Body Parts
- ab
- the muscles of the abdomen
- abdomen
- the cavity containing the major viscera; in mammals it is separated from the thorax by the diaphragm
- abdomen
- the region of the body of a vertebrate between the thorax and the pelvis
- abdominal aorta
- a branch of the descending aorta
- abdominal external oblique muscle
- a diagonally arranged abdominal muscle on either side of the torso
- abdominal nerve plexus
- a large plexus of sympathetic nerves in the abdomen behind the stomach
- abducens muscle
- the ocular muscle whose contraction turns the eyeball outward
- abducens
- a small motor nerve supplying the lateral rectus muscle of the eye
- abductor
- a muscle that draws a body part away from the median line
- abomasum
- the fourth compartment of the stomach of a ruminant; the one where digestion takes place
- acanthion
- the craniometric point at the anterior extremity of the intermaxillary suture
- accessory cephalic vein
- a vein that passes along the radial edge of the forearm and joins the cephalic vein near the elbow
- accessory hemiazygos vein
- a vein formed by the union of the 4th to 7th posterior intercostal veins; empties into the azygos vein
- accessory nerve
- arises from two sets of roots (cranial and spinal) that unite to form the nerve
- accessory vertebral vein
- a vein that accompanies the vertebral vein but passes through the foramen of the transverse process of the 7th cervical vertebra and empties into the brachiocephalic vein
- accompanying vein
- a vein accompanying another structure; a vein may accompany an artery in such a way that the arterial pulses aid venous return
- acetabulum
- the cup-shaped hollow in the hipbone into which the head of the femur fits to form a ball-and-socket joint
- acinus
- one of the small sacs or saclike dilations in a compound gland
- acoustic meatus
- either of the passages in the outer ear from the auricle to the tympanic membrane
- acoustic nerve
- a composite sensory nerve supplying the hair cells of the vestibular organ and the hair cells of the cochlea
- acromial process
- the outermost point of the spine of the shoulder blade
- acrosome
- a process at the anterior end of a sperm cell that produces enzymes to facilitate penetration of the egg
- aculea
- small spiny outgrowth on the wings of certain insects
- aculeus
- a sharp-pointed process especially a sting of a hymenopterous insect
- aculeus
- a stiff sharp-pointed plant process
- acumen
- a tapering point
- Adam's apple
- the largest cartilage of the larynx
- adductor
- a muscle that draws a body part toward the median line
- adenohypophysis
- the anterior lobe of the pituitary body; primarily glandular in nature
- adhesion
- a fibrous band of scar tissue that binds together normally separate anatomical structures
- adipose tissue
- a kind of body tissue containing stored fat that serves as a source of energy; it also cushions and insulates vital organs
- adnexa
- accessory or adjoining anatomical parts or appendages to an organ (especially of the embryo)
- adrenal cortex
- the cortex of the adrenal gland; secretes corticosterone and sex hormones
- adrenal medulla
- the medulla of the adrenal gland; secretes epinephrine
- adrenal
- either of a pair of complex endocrine glands situated near the kidney
- adult tooth
- any of the 32 teeth that replace the deciduous teeth of early childhood and (with luck) can last until old age
- adventitia
- an enveloping or covering membrane or layer of body tissue
- afferent
- a nerve that passes impulses from receptors toward or to the central nervous system
- afterbirth
- the placenta and fetal membranes that are expelled from the uterus after the baby is born
- agnail
- a loose narrow strip of skin near the base of a fingernail; tearing it produces a painful sore that is easily infected
- agonist
- a muscle that contracts while another relaxes
- air bladder
- an air-filled sac near the spinal column in many fishes that helps maintain buoyancy
- air cell
- a tiny sac for holding air in the lungs; formed by the terminal dilation of tiny air passageways
- air sac
- any of the membranous air-filled extensions of the lungs of birds
- air sac
- any of the thin-walled extensions of the tracheae of insects
- airway
- the passages through which air enters and leaves the body
- ala
- a wing of an insect
- ala
- a flat wing-shaped process or winglike part of an organism
- albuginea
- whitish tunic
- allantois
- the vascular fetal membrane that lies below the chorion and develops from the hindgut in many embryonic higher vertebrates (reptiles, birds and mammals)
- allograft
- tissue or organ transplanted from a donor of the same species but different genetic makeup; recipient's immune system must be suppressed to prevent rejection of the graft
- alpha receptor
- receptors postulated to exist on nerve cell membranes of the sympathetic nervous system in order to explain the specificity of certain agents that affect only some sympathetic activities (such as vasoconstriction and relaxation of intestinal muscles and contraction of smooth muscles)
- alveolar arch
- the part of the upper or lower jawbones in which the teeth are set
- alveolar artery
- a branch of the maxillary artery that supplies the alveolar process
- alveolar bed
- lung tissue densely packed with alveoli
- alveolar point
- craniometric point that is the most anterior point in the midline on the alveolar process of the maxilla
- alveolar process
- a ridge that forms the borders of the upper and lower jaws and contains the sockets of the teeth
- alveolus
- a bony socket in the alveolar ridge that holds a tooth
- ambulacrum
- one of the five areas on the undersurface of an echinoderm on which the tube feet are located
- amnion
- thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
- amniotic cavity
- the fluid-filled cavity that surrounds the developing embryo
- ampulla
- the dilated portion of a canal or duct especially of the semicircular canals of the ear
- amygdala
- an almond-shaped neural structure in the anterior part of the temporal lobe of the cerebrum; intimately connected with the hypothalamus and the hippocampus and the cingulate gyrus; as part of the limbic system it plays an important role in motivation and emotional behavior
- anal sphincter
- the sphincter muscle of the anus
- anastomotic vein
- either of two communicating veins serving the brain
- anatomical sphincter
- a ring of muscle that contracts to close an opening
- anatomical structure
- a particular complex anatomical part of a living thing and its construction and arrangement
- anconeous muscle
- the muscle that extends the forearm and abducts the ulna in pronation of the wrist
- angular artery
- the terminal branch of the facial artery
- angular vein
- a short vein formed by the supraorbital vein and the supratrochlear vein and continuing as the facial vein
- animal foot
- the pedal extremity of vertebrates other than human beings
- animal leg
- the leg of an animal
- animal tissue
- the tissue in the bodies of animals
- ankle
- a gliding joint between the distal ends of the tibia and fibula and the proximal end of the talus
- anklebone
- the bone in the ankle that articulates with the leg bones to form the ankle joint
- anlage
- an organ in its earliest stage of development; the foundation for subsequent development
- annualry
- the third finger (especially of the left hand)
- ANS
- the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands
- antagonist
- a muscle that relaxes while another contracts
- antagonistic muscle
- (physiology) a muscle that opposes the action of another
- antenna
- one of a pair of mobile appendages on the head of e.g. insects and crustaceans; typically sensitive to touch and taste
- anterior cardinal vein
- a major drainage channel from the cephalic part of the body
- anterior cerebral artery
- one of two branches of the internal carotid artery; divides into two branches that serve (1) the thalamus and (2) parts of the frontal and parietal cortex
- anterior cerebral vein
- accompanies the anterior cerebral artery and empties into the basal vein
- anterior crural nerve
- one of a pair of nerves that originate from lumbar nerves and supply the muscles and skin of the anterior part of the thigh
- anterior facial vein
- a continuation of the angular vein; unites with the retromandibular vein before emptying into the internal jugular vein
- anterior fontanelle
- corresponds to the bregma when bones have ossified
- anterior horn
- one of the two roots of a spinal nerve that passes ventrally from the spinal cord and that consists of motor fibers
- anterior jugular vein
- arises below the chin from veins draining the lower face; joins the external jugular vein
- anterior labial veins
- veins from the labia majora to the external pudendal vein
- anterior meningeal artery
- branch of the anterior ethmoidal artery that supplies meninges in the anterior cranial fossa
- anterior naris
- either one of the two external openings to the nasal cavity in the nose
- anterior serratus muscle
- muscles that rotate the scapula and elevate the rib cage
- anterior temporal artery
- temporal artery that goes to the anterior part of the cerebral cortex of the temporal lobe
- anterior vertebral vein
- a vein that accompanies the ascending cervical artery and opens into the vertebral vein
- anterior
- a tooth situated at the front of the mouth
- antler
- deciduous horn of a member of the deer family
- antrum
- a natural cavity or hollow in a bone
- anus
- the excretory opening at the end of the alimentary canal
- anvil
- the ossicle between the malleus and the stapes
- aorta
- the large trunk artery that carries blood from the left ventricle of the heart to branch arteries
- aortic arch
- the part of the aorta that arches and turns downward
- aortic orifice
- the orifice from the lower left chamber of the heart to the aorta
- aortic plexus
- a plexus of lymph nodes in the lower portion of the abdominal aorta
- aortic valve
- a semilunar valve between the left ventricle and the aorta; prevents blood from flowing from the aorta back into the heart
- apocrine gland
- a large sweat gland that produces both a fluid and an apocrine secretion; in human beings located in hairy regions of the body
- apodeme
- ridge-like ingrowth of the exoskeleton of an arthropod that supports internal organs and provides attachment points for muscles
- aponeurosis
- any of the deeper and thicker fascia that attach muscles to bones; resemble flattened tendons
- apophysis
- (botany) a natural swelling or enlargement: at the base of the stalk or seta in certain mosses or on the cone scale of certain conifers
- apophysis
- (anatomy) a natural outgrowth or projection on an organ or body part such as the process of a vertebra
- apparatus
- (anatomy) a group of body parts that work together to perform a given function
- apparatus urogenitalis
- the system that includes all organs involved in reproduction and in the formation and voidance of urine
- appendage
- an external body part that projects from the body
- appendage
- a natural prolongation or projection from a part of an organism either animal or plant
- appendicular artery
- the branch of the ileocolic artery that supplies the vermiform appendix
- appendicular skeleton
- the part of the skeleton that includes the pectoral girdle and the pelvic girdle and the upper and lower limbs
- appendicular vein
- a vein that accompanies the appendicular artery and empties into the ileocolic vein
- appendix
- a vestigial process that extends from the lower end of the cecum and that resembles a small pouch
- arachnoid
- the middle of the 3 meninges
- arch
- a curved bony structure supporting or enclosing organs (especially the inner sides of the feet)
- archenteron
- central cavity of the gastrula; becomes the intestinal or digestive cavity
- archipallium
- the olfactory cortex of the cerebrum
- arcuate artery of the kidney
- curved arteries of the kidney
- arcuate artery
- curved artery in the foot
- arcuate vein of the kidney
- veins that receive blood from interlobular veins of kidney and rectal venules
- arcus zygomaticus
- the slender arch formed by the temporal process of the cheekbone that bridges to the zygomatic process of the temporal bone
- arcus
- a whitish deposit in the shape of an arc that is sometimes seen in the cornea
- area 17 of Brodmann
- the part of the occipital cortex that receives the fibers of the optic radiation from the lateral geniculate body and is the primary receptive area for vision
- area of cardiac dullness
- a triangular area of the front of the chest (determined by percussion); corresponds to the part of the heart not covered by the lungs
- area
- a part of an animal that has a special function or is supplied by a given artery or nerve
- areola
- small space in a tissue or body part such as the area between veins on a leaf or an insect's wing
- areola
- small circular area such as that around the human nipple or an inflamed area around a pimple or insect bite
- areolar tissue
- fibrous connective tissue with the fibers arranged in a mesh or net
- areteria cervicalis
- an artery that supplies the muscles of the neck
- arista
- bristlelike process near the tip of the antenna of certain flies
- arm
- a human limb; technically the part of the superior limb between the shoulder and the elbow but commonly used to refer to the whole superior limb
- arm bone
- a bone in the arm
- armpit
- the hollow under the arm where it is joined to the shoulder
- arse
- vulgar slang for anus
- arse
- the fleshy part of the human body that you sit on
- arteria alveolaris inferior
- the alveolar artery that goes through the mandibular canal to supply the lower teeth
- arteria alveolaris superior
- the alveolar artery that supplies the upper teeth
- arteria ascendens
- the branch of the ileocolic artery that supplies the ascending colon
- arteria auricularis
- artery that supplies blood to the ear
- arteria axillaris
- the part of the main artery of the arm that lies in the armpit and is continuous with the subclavian artery above and the brachial artery below
- arteria basilaris
- an unpaired artery; supplies the pons and cerebellum and the back part of the cerebrum and the inner ear
- arteria brachialis
- the main artery of the upper arm; a continuation of the axillary artery; bifurcates into the radial and ulnar arteries at the elbow
- arteria buccalis
- a branch of the maxillary artery that supplies blood to the buccinator muscle and the cheek
- arteria bulbi penis
- a branch of the internal pudendal artery of males that supplies the bulb of the penis
- arteria bulbi vestibuli
- a branch of the internal pudendal artery in females that supplies the bulb of the vestibule
- arteria carotis
- either of two major arteries of the neck and head; branches from the aorta
- arteria celiaca
- an artery that originates from the abdominal aorta just below the diaphragm and branches into the left gastric artery and the common hepatic artery and the splenic artery
- arteria centralis retinae
- a branch of the ophthalmic artery; enters the eyeball with the optic nerve
- arteria cerebelli
- an artery that supplies the cerebellum
- arteria cerebri
- any of the arteries supplying blood to the cerebral cortex
- arteria choroidea
- an artery that supplies the choroid plexus
- arteria ciliaris
- one of several arteries supplying the choroid coat of the eye
- arteria circumflexa femoris
- an artery that supplies the hip joint and thigh muscles
- arteria circumflexa humeri
- an artery that supplies the shoulder joint and shoulder muscles
- arteria circumflexa ilium
- an artery that supplies the lower abdominal walls and skin and the sartorius muscle
- arteria circumflexa scapulae
- an artery that serves the muscles of the shoulder and scapular area
- arteria colica
- arteries that supply blood to the colon
- arteria communicans
- any of three arteries in the brain that make up the circle of Willis
- arteria coronaria
- the artery that branches from the aorta to supply blood to the heart
- arteria cystica
- a branch of the hepatic artery; supplies the gall bladder and the surface of the liver
- arteria digitalis
- arteries in the hand and foot that supply the fingers and toes
- arteria epigastrica
- one of three arteries supplying the anterior walls of the abdomen
- arteria ethmoidalis
- a branch of the ophthalmic artery supplying structures in and around the nasal capsule
- arteria facialis
- an artery that originates in the external carotid and gives off branches that supply the neck and face
- arteria femoralis
- the chief artery of the thigh; a continuation of the external iliac artery
- arteria gastrica breves
- several small arteries branching off of the splenic artery and going to the greater curvature of the stomach
- arteria gastrica sinistra
- a branch of the celiac artery that supplies the lesser curvature of the stomach and the abdominal part of the esophagus
- arteria gastrica
- the arteries that supply the walls of the stomach
- arteria glutes
- branches of the internal iliac artery that supply the hip joint and gluteal region
- arteria hepatica
- arteries that supply the liver
- arteria ileocolica
- an artery that originates from the superior mesenteric artery and supplies the terminal part of the ileum and the cecum and the vermiform appendix and the ascending colon
- arteria ileum
- branch of the superior mesenteric artery that supplies the ileum
- arteria iliaca
- one of the large arteries supplying blood to the pelvis and legs
- arteria iliolumbalis
- an artery that originates in the internal iliac artery and supplies the pelvic muscles and bones
- arteria infraorbitalis
- an artery that originates from the maxillary artery and supplies structures below the orbit (from lower eyelid to upper lip)
- arteria intercostalis
- several arteries and supplying the intercostal spaces of the rib cage
- arteria labialis inferior
- an artery that is a branch of the facial artery that supplies the lower lip
- arteria labialis superior
- an artery that is a branch of the facial artery that supplies the upper lip
- arteria labialis
- an artery that is a branch of the facial artery that supplies the lips of the mouth
- arteria lacrimalis
- an artery that originates from the ophthalmic artery and supplies the lacrimal gland and rectal eye muscles and the upper eyelid and the forehead
- arteria laryngea
- either of two arteries that supply blood to the larynx
- arteria lienalis
- an artery that originates from the celiac trunk and supplies blood to the spleen
- arteria lingualis
- an artery originating from the external carotid artery and supplying the under side of the tongue
- arteria lumbalis
- one of four or five pairs of arteries that originate in the abdominal aorta and supply the lumbar vertebrae and the back muscles and abdominal wall
- arteria maxillaris
- either of two arteries branching from the external carotid artery and supplying structure of the face
- arteria meningea
- any of three arteries supplying the meninges of the brain and neighboring structures
- arteria mesenterica
- one of two branches of the aorta that pass between the two layers of the mesentery to the intestines
- arteria metacarpea
- dorsal and palmar arteries of the hand
- arteria metatarsea
- dorsal and plantar arteries to the metatarsal region of the foot
- arteria musculophrenica
- an artery that supplies the abdomen and intercostal muscles
- arteria nutricia
- an artery that supplies the medullary cavity of the long bone
- arteria ophthalmica
- a branch of the internal carotid artery that supplies the eye and neighboring structures
- arteria ovarica
- the artery that branches from the aorta and supplies blood to the ovaries
- arteria palatina
- one of several arteries supplying the face
- arteria pancreatica
- a branch of the splenic artery that supplies the pancreas
- arteria perinealis
- a branch of the internal pudendal artery that supplies superficial structures of the perineum
- arteria poplitea
- a continuation of the femoral artery that branches to supply the legs and feet
- arteria pudenda
- arteries supplying the external genital organs of humans
- arteria pulmonalis
- one of two arteries (branches of the pulmonary trunk) that carry venous blood from the heart to the lungs
- arteria radialis
- branch of the brachial artery beginning below the elbow and extending down the forearm around the wrist and into the palm
- arteria rectalis
- one of the arteries supplying the rectal area
- arteria renalis
- an artery originating from the abdominal aorta and supplying the kidneys and adrenal glands and ureters
- arteria subclavia
- either of two arteries that supply blood to the neck and arms
- arteria temporalis intermedia
- temporal artery that goes to the middle part of the cerebral cortex of the temporal lobe
- arteria temporalis posterior
- temporal artery that supplies the posterior part of the cortex of the temporal lobe
- arteria testicularis
- a branch of the aorta supplying the testicles
- arteria ulnaris
- large artery that branches from the brachial artery to supply the muscles of the forearm and wrist and hand
- arteria uterina
- a branch of the internal iliac artery that supplies the uterus and the upper part of the vagina
- arteria vaginalis
- a branch of the internal iliac that provides blood for the vagina and the base of the bladder and the rectum
- arteria vertebralis
- the first branch of the subclavian artery; divided into four parts
- arteria
- a blood vessel that carries blood from the heart to the body
- arteriola
- one of the small thin-walled arteries that end in capillaries
- artery of the labyrinth
- an artery that is a branch of the basilar artery that supplies the labyrinth
- arthromere
- any of the segments in the body of a jointed animal like an arthropod
- articular muscle
- a muscle that inserts directly onto the capsule of a joint
- articulatio coxae
- the ball-and-socket joint between the head of the femur and the acetabulum
- articulatio cubiti
- hinge joint between the forearm and upper arm and the corresponding joint in the forelimb of a quadruped
- articulatio genus
- hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella
- articulatio humeri
- a ball-and-socket joint between the head of the humerus and a cavity of the scapula
- articulatio plana
- a freely moving joint in which the articulations allow only gliding motions
- articulatio radiocarpea
- a joint between the distal end of the radius and the proximal row of carpal bones
- articulatio spheroidea
- a freely moving joint in which a sphere on the head of one bone fits into a rounded cavity in the other bone
- articulatio synovialis
- a joint so articulated as to move freely
- articulatio temporomandibularis
- the joint between the head of the lower jawbone and the temporal bone
- articulatio trochoidea
- a freely moving joint in which movement is limited to rotation
- articulatio
- (anatomy) the point of connection between two bones or elements of a skeleton (especially if it allows motion)
- articulator
- a movable speech organ
- articulatory system
- the system of joints in the body
- arytaenoid
- either of two small cartilages at the back of the larynx to which the vocal folds are attached
- ascending aorta
- the ascending part of the aorta as it emerges from the left ventricle
- ascending colon
- the part of the large intestine that ascends from the cecum to the transverse colon
- association area
- cortical areas that are neither motor or sensory but are thought to be involved in higher processing of information
- aster
- star-shaped structure formed in the cytoplasm of a cell having fibers like rays that surround the centrosome during mitosis
- asterion
- the craniometric point at the junction of the lamboid suture and the occipitomastoid suture and the parietomastoid suture
- astroglia
- tissue consisting of large stellate neuroglial cells
- ateria gastrica dextra
- a branch of the hepatic artery that supplies the pyloric portion of the stomach on the lesser curvature
- atheroma
- a fatty deposit in the intima (inner lining) of an artery; can obstruct blood flow
- athlete's heart
- enlarged heart commonly found among athletes trained for endurance
- atlas
- the 1st cervical vertebra
- atrial artery
- the branch of the coronary artery that supplies the muscles of the atria
- atrial auricle
- a small conical pouch projecting from the upper anterior part of each atrium of the heart
- atrioventricular node
- a node of specialized heart muscle located in the septal wall of the right atrium; receives impulses from the sinoatrial node and transmits them to atrioventricular bundle
- atrioventricular valve
- either of two heart valves through which blood flows from the atria to the ventricles; prevents return of blood to the atrium
- atrium
- any chamber that is connected to other chambers or passageways (especially one of the two upper chambers of the heart)
- atrium cordis
- the upper chamber of each half of the heart
- atrium dextrum
- the right upper chamber of the heart that receives blood from the venae cavae and coronary sinus
- atrium sinistrum
- the left upper chamber of the heart that receives blood from the pulmonary veins
- attic
- informal terms for a human head
- auditory apparatus
- all of the components of the organ of hearing including the outer and middle and inner ears
- auditory area
- the cortical area that receives auditory information from the medial geniculate body
- auditory center
- the part of the brain (in a fold of the cerebral cortex of the temporal lobe on both sides of the brain) that receives impulses from the ear by way of the auditory nerve
- auditory ossicle
- ossicles of the middle ear that transmit acoustic vibrations from the eardrum to the inner ear
- auditory system
- the sensory system for hearing
- auricle
- the externally visible cartilaginous structure of the external ear
- auricula
- a pouch projecting from the top front of each atrium of the heart
- auricular point
- the craniometric point at the center of the opening of the external acoustic meatus
- auricular vein
- one of two veins serving the ear region
- autograft
- tissue that is taken from one site and grafted to another site on the same person
- autonomic ganglion
- any of the ganglia of the autonomic system whose unmyelinated fibers innervate the internal organs
- autonomic plexus
- a plexus of sympathetic and parasympathetic nerve fibers
- awn
- slender bristlelike appendage found on the bracts of grasses
- axial muscle
- a skeletal muscle of the trunk or head
- axial skeleton
- the part of the skeleton that includes the skull and spinal column and sternum and ribs
- axillary node
- any of the lymph glands of the armpit; fights infections in the neck and chest and arm regions
- axillary vein
- a continuation of the basilic vein and brachial vein that becomes the subclavian vein
- axis
- the 2nd cervical vertebra; serves as a pivot for turning the head
- axolemma
- outer membrane covering an axon
- azygos vein
- one of a system of veins that drain the thoracic and abdominal walls; arises as a continuation of the right ascending lumbar vein and terminates in the superior vena cava
- baby tooth
- one of the first temporary teeth of a young mammal (one of 20 in children)
- back tooth
- a tooth situated at the back of the mouth
- back
- the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
- back
- the posterior part of a human (or animal) body from the neck to the end of the spine
- bag
- mammary gland of bovids (cows and sheep and goats)
- balancer
- either of the rudimentary hind wings of dipterous insects; used for maintaining equilibrium during flight
- ball
- a more or less rounded anatomical body or mass
- ball
- one of the two male reproductive glands that produce spermatozoa and secrete androgens
- band
- a cord-like tissue connecting two larger parts of an anatomical structure
- bandy leg
- a leg bowed outward at the knee (or below the knee)
- barbel
- slender tactile process on the jaws of a fish
- bare bone
- bone stripped of flesh
- baroreceptor
- a sensory receptor that responds to pressure
- Bartholin's gland
- either of the two posterior vestibular glands that secrete a lubricating mucus; homologous to Cowper's gland in the male
- basal ganglion
- any of several masses of subcortical grey matter at the base of each cerebral hemisphere that seem to be involved in the regulation of voluntary movement
- basal vein
- a large vein passing along the medial surface of the temporal lobe and emptying into the great cerebral vein
- basilar membrane
- a membrane in the cochlea that supports the organ of Corti
- basilic vein
- a vein that drains the back of the hand and forearm and empties into the axillary vein
- basivertebral vein
- one of a number of veins draining the spongy substance of the vertebrae and emptying into the anterior internal vertebral venous plexus
- bay window
- slang for a paunch
- beak
- beaklike mouth of animals other than birds (e.g., turtles)
- beak
- horny projecting mouth of a bird
- beak
- informal terms for the nose
- bear claw
- claw of a bear; often used in jewelry
- beard
- a tuft or growth of hairs or bristles on certain plants such as iris or grasses
- belly
- the underpart of the body of certain vertebrates such as snakes or fish
- belly
- a protruding abdomen
- beta receptor
- receptors postulated to exist on nerve cell membranes of the sympathetic nervous system in order to explain the specificity of certain agents that affect only some sympathetic activities (such as vasodilation and increased heart beat)
- betweenbrain
- the posterior division of the forebrain; connects the cerebral hemispheres with the mesencephalon
- biauriculate heart
- a heart (as of mammals and birds and reptiles) having two auricles
- biceps
- any skeletal muscle having two origins (but especially the muscle that flexes the forearm)
- biceps brachii
- a muscle that flexes and supinates the forearm
- bicuspid valve
- valve with two cusps; situated between the left atrium and the left ventricle
- bicuspid
- a tooth having two cusps or points; located between the incisors and the molars
- big toe
- the first largest innermost toe
- bile duct
- a duct formed by the hepatic and cystic ducts; opens into the duodenum
- biliary ductule
- excretory ducts of the liver; empty into the hepatic ducts
- bird's foot
- the foot of a bird
- birth canal
- a passage in the uterus and vagina through which a fetus passes during vaginal birth
- bladder sphincter
- the sphincter muscle of the urinary bladder; made up of a thickened muscular layer of bladder around the urethral opening
- bladder
- a distensible membranous sac (usually containing liquid or gas)
- blade
- a broad flat body part (as of the shoulder or tongue)
- blastocele
- the fluid-filled cavity inside a blastula
- blastoderm
- a layer of cells on the inside of the blastula
- blastopore
- the opening into the archenteron
- bleb
- (pathology) an elevation of the skin filled with serous fluid
- blind gut
- the cavity in which the large intestine begins and into which the ileum opens
- blister
- (botany) a swelling on a plant similar to that on the skin
- blood blister
- blister containing blood or bloody serum usually caused by an injury
- blood vessel
- a vessel in which blood circulates
- blowhole
- the spiracle of a cetacean located far back on the skull
- bob
- a short or shortened tail of certain animals
- bodily cavity
- (anatomy) a natural hollow or sinus within the body
- body
- the body excluding the head and neck and limbs
- bone marrow
- the fatty network of connective tissue that fills the cavities of bones
- bone
- rigid connective tissue that makes up the skeleton of vertebrates
- bonelet
- a small bone; especially one in the middle ear
- bony labyrinth
- cavity in the petrous part of the temporal bone that contains the membranous labyrinth
- boob
- either of two soft fleshy milk-secreting glandular organs on the chest of a woman
- book lung
- organ in many arachnids containing many thin folds of membrane resembling the leaves of a book
- bosom
- a person's breast or chest
- bowel
- the part of the alimentary canal between the stomach and the anus
- Bowman's capsule
- thin double membrane surrounding the glomerulus of a nephron
- brachial plexus
- a network of nerves formed by cervical and thoracic spinal nerves and supplying the arm and parts of the shoulder
- brachial vein
- two veins in either arm that accompany the brachial artery and empty into the axillary vein
- brachiocephalic vein
- veins formed by the union of the internal jugular and subclavian veins
- brain stem
- the part of the brain continuous with the spinal cord and comprising the medulla oblongata and pons and midbrain and parts of the hypothalamus
- brain
- that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord
- braincase
- the part of the skull that encloses the brain
- branchia
- respiratory organ of aquatic animals that breathe oxygen dissolved in water
- branchial arch
- one of the bony or cartilaginous arches on each side of the pharynx that support the gills of fishes and aquatic amphibians
- branchial cleft
- one of a series of slit openings in the pharynxes of fishes and aquatic amphibians through which water passes
- breadbasket
- an enlarged and muscular saclike organ of the alimentary canal; the principal organ of digestion
- breast
- the part of an animal's body that corresponds to a person's chest
- breast
- the front of the trunk from the neck to the abdomen
- breastbone
- the flat bone that articulates with the clavicles and the first seven pairs of ribs
- bregma
- the craniometric point at the junction of the sagittal and coronal sutures at the top of the cranium
- bridge
- the hard ridge that forms the upper part of the nose
- bristle
- a stiff hair
- Brodmann's area
- one of the cortical areas mapped out on the basis of its cytoarchitecture
- bronchial artery
- arteries that accompany the bronchioles
- bronchial tube
- either of the two main branches of the trachea
- bronchial vein
- veins serving the bronchi; empty into the azygos vein
- bronchiole
- any of the smallest bronchial ducts; ending in alveoli
- brow
- the part of the face above the eyes
- brush
- a bushy tail or part of a bushy tail (especially of the fox)
- bubo
- a lymph node that is inflamed and swollen because of plague or gonorrhea or tuberculosis
- buccal cavity
- the cavity between the jaws and the cheeks
- buccinator muscle
- a muscle that flattens the cheek and retracts the angle of the mouth
- buccula
- a fold of fatty tissue under the chin
- bucktooth
- a large projecting front tooth
- buff
- bare skin
- bulb
- a rounded dilation or expansion in a canal or vessel or organ
- bulb
- lower or hindmost part of the brain; continuous with spinal cord; (`bulb' is an old term for medulla oblongata)
- bulbar conjunctiva
- the part of the conjunctiva covering the anterior face of the sclera and the surface epithelium of the cornea
- bull neck
- a thick short powerful neck
- bullethead
- a head shaped like a bullet
- bundle of His
- a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract
- burl
- a large rounded outgrowth on the trunk or branch of a tree
- bursa
- a small fluid-filled sac located between movable parts of the body especially at joints
- bursa omentalis
- an isolated part of the peritoneal cavity that is dorsal to the stomach
- bust
- the chest of a woman
- buttock
- either of the two large fleshy masses of muscular tissue that form the human rump
- button
- a female sexual organ homologous to the penis
- bypass
- a surgically created shunt (usually around a damaged part)
- cakehole
- informal terms for the mouth
- calamus
- the hollow spine of a feather
- calcaneus
- the largest tarsal bone; forms the human heel
- calcarine fissure
- a sulcus in the mesial surface of the occipital lobe of the cerebrum
- calf bone
- the outer and thinner of the two bones of the human leg between the knee and ankle
- calf
- the muscular back part of the shank
- caliculus
- a small cup-shaped structure (as a taste bud or optic cup or cavity of a coral containing a polyp)
- callus
- (botany) an isolated thickening of tissue, especially a stiff protuberance on the lip of an orchid
- calvaria
- the dome of the skull
- canal of Schlemm
- a circular canal in the eye that drains aqueous humor from the anterior chamber of the eye into the anterior ciliary veins
- canal
- a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance
- canaliculus
- a small canal or duct as in some bones and parts of plants
- canalis cervicis uteri
- a spindle-shaped canal extending from the uterus to the vagina
- canalis inguinalis
- oblique passage through the lower abdominal wall; in males it is the passage through which the testes descend into the scrotum and it contains the spermatic cord; in females it transmits the round ligament of the uterus
- canalis vertebralis
- the canal in successive vertebrae through which the spinal cord passes
- canine
- one of the four pointed conical teeth (two in each jaw) located between the incisors and the premolars
- cannon bone
- greatly developed metatarsal or metacarpal bone in the shank or cannon part of the leg in hoofed mammals
- cannon
- lower part of the leg extending from the hock to the fetlock in hoofed mammals
- capillary bed
- a layer of tissue densely packed with capillaries
- capillary vein
- a minute vein continuous with a capillary
- capillary
- any of the minute blood vessels connecting arterioles with venules
- capitate
- the wrist bone with a rounded head shape that articulates with the 3rd metacarpus
- capsule
- a structure that encloses a body part
- caput
- the upper part of the human body or the front part of the body in animals; contains the face and brains
- cardia
- the opening into the stomach and that part of the stomach connected to the esophagus
- cardiac muscle
- the muscle tissue of the heart; adapted to continued rhythmic contraction
- cardiac plexus
- a plexus of nerves supplying the heart and nearby structures
- cardiac sphincter
- the valve between the distal end of the esophagus and the stomach; the physiological sphincter at the esophagogastric junction
- cardiac valve
- a valve to control one-way flow of blood
- cardinal vein
- any of the major venous channels in primitive adult vertebrates and in embryos of higher vertebrates
- cardiovascular system
- the organs and tissues involved in circulating blood and lymph through the body
- carina
- any of various keel-shaped structures or ridges such as that on the breastbone of a bird or that formed by the fused petals of a pea blossom
- carina fornicis
- ridge on the lower surface of the fornix of the brain
- carnassial tooth
- the last upper premolar and first lower molar teeth of a carnivore; having sharp edges for cutting flesh
- carotid body
- a chemoreceptor located near the bifurcations of the carotid arteries; monitors oxygen content of the blood and helps control respiration
- carotid plexus
- a plexus of nerves surrounding the internal carotid artery
- carpal tunnel
- a passageway in the wrist through which nerves and the flexor muscles of the hands pass
- carpal
- any of the eight small bones of the wrist of primates
- cartilage bone
- any bone that develops within cartilage rather than a fibrous tissue
- cartilage
- tough elastic tissue; mostly converted to bone in adults
- cartilaginous structure
- body structure given shape by cartilage
- cartilaginous tube
- a duct with cartilaginous walls
- caruncle
- an outgrowth on a plant or animal such as a fowl's wattle or a protuberance near the hilum of certain seeds
- cauda
- any taillike structure
- caudal appendage
- tail especially of a mammal posterior to and above the anus
- caudal fin
- the tail of fishes and some other aquatic vertebrates
- caudal vertebra
- one of 4 vertebrae in the human coccyx
- caudate
- a tail-shaped basal ganglion located in a lateral ventricle of the brain
- caul
- the inner membrane of embryos in higher vertebrates (especially when covering the head at birth)
- caul
- part of the peritoneum attached to the stomach and to the colon and covering the intestines
- cauliflower ear
- an auricle deformed by injury; common among boxers
- cavernous sinus
- either of a pair of large venous sinuses in the cranial cavity
- cell membrane
- a thin membrane (a double layer of lipids) enclosing the cytoplasm of a cell; proteins in the membrane control passage of ions (like sodium or potassium or calcium) in and out of the cell
- cell nucleus
- a part of the cell containing DNA and RNA and responsible for growth and reproduction
- cell organ
- a specialized part of a cell; analogous to an organ
- cellulite
- lumpy deposits of body fat especially on women's thighs etc.
- celom
- a cavity in the mesoderm of an embryo that gives rise in humans to the pleural cavity and pericardial cavity and peritoneal cavity
- center
- a cluster of nerve cells governing a specific bodily process
- central gyrus
- either of two gyri on either side of the central sulcus
- central vein of retina
- vein formed by the union of the retinal veins; accompanies central arteries of the retina in the optic nerve
- central vein of suprarenal gland
- a single draining vein; on the right it empties into the inferior vena cava; on the left it empties into the left renal vein
- central veins of liver
- terminal branches of the hepatic veins that lie in the hepatic lobules and receive blood from the liver sinusoids
- centriole
- one of a pair of small cylindrical cell organelles near the nucleus in animal cells; composed of nine triplet microtubules and form the asters during mitosis
- centromere
- a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape
- centrum
- the main body of a vertebra
- cephalic vein
- a large vein of the arm that empties into the axillary vein
- ceras
- one of the often brightly colored and branching hornlike structures on the back of the nudibranch (and other related mollusks) that serve as gills
- cere
- the fleshy, waxy covering at the base of the upper beak of some birds
- cerebellar hemisphere
- either of two lateral lobes of the cerebellum
- cerebellar vein
- the veins draining the cerebellum
- cerebellum
- a major division of the vertebrate brain; situated above the medulla oblongata and beneath the cerebrum in humans
- cerebral cortex
- the layer of unmyelinated neurons (the grey matter) forming the cortex of the cerebrum
- cerebral hemisphere
- either half of the cerebrum
- cerebral peduncle
- a bundle of myelinated neurons joining different parts of the brain
- cerebral vein
- any of several veins serving the cerebral hemispheres of the brain
- cerebrum
- anterior portion of the brain consisting of two hemispheres; dominant part of the brain in humans
- cervical glands
- mucus-secreting glands in the mucosa of the uterine cervix
- cervical nerve
- any of eight pairs of spinal nerves emerging from the cervical section of the spinal cord
- cervical plexus
- a nerve plexus lying beneath the sternocleidomastoid muscle
- cervical vein
- a vein that accompanies an artery of the same name
- cervical vertebra
- one of 7 vertebrae in the human spine located in the neck region
- cervix
- necklike opening to the uterus
- cervix
- the part of an organism (human or animal) that connects the head to the rest of the body
- chaeta
- a stiff chitinous seta or bristle especially of an annelid worm
- chalaza
- one of two spiral bands of tissue connecting the egg yolk to the enclosing membrane at either end of the shell
- chamber
- an enclosed volume in the body
- cheek
- either side of the face below the eyes
- cheek pouch
- a membranous pouch inside the mouth of many rodents (as a gopher)
- cheekbone
- the arch of bone beneath the eye that forms the prominence of the cheek
- chela
- a grasping structure on the limb of a crustacean or other arthropods
- chelicera
- either of the first pair of fang-like appendages near the mouth of an arachnid; often modified for grasping and piercing
- chemoreceptor
- a sensory receptor that responds to chemical stimuli
- chest cavity
- the cavity in the vertebrate body enclosed by the ribs between the diaphragm and the neck and containing the lungs and heart
- chest
- the part of the human torso between the neck and the diaphragm or the corresponding part in other vertebrates
- chiasm
- an intersection or crossing of two tracts in the form of the letter X
- chiasma opticum
- the crossing of the optic nerves from the two eyes at the base of the brain
- chin
- the protruding part of the lower jaw
- chine
- backbone of an animal
- chondriosome
- an organelle containing enzymes responsible for producing energy
- chop
- a jaw
- chopper
- informal terms for a human `tooth'
- chordamesoderm
- the area of mesoderm that forms the notochord
- chorioallantoic membrane
- the very vascular fetal membrane composed of the fused chorion and adjacent wall of the allantois
- chorion
- the outermost membranous sac enclosing the embryo in higher vertebrates (reptiles, birds and mammals)
- chorionic villus
- one of the tiny villi that stick out of the fetal chorion and combine with the mother's uterine tissue to form the placenta
- choroid plexus
- a vascular plexus of the cerebral ventricles that regulate intraventricular pressure
- choroid vein
- either of two veins serving the choroid coat of the eye
- choroid
- a highly vascular membrane in the eye between the retina and the sclera; a dark pigmentation minimizes the scattering of light inside the eye
- ciliary body
- the part of the tunic of the eye between the choroid coat and the iris
- ciliary veins
- small veins coming from the ciliary body
- cilium
- a hairlike projection from the surface of a cell; provides locomotion in free-swimming unicellular organisms
- cingulate gyrus
- a long curved structure on the medial surface of the cerebral hemispheres; the cortical part of the limbic system
- cingulum
- (anatomy) an encircling structure (as the ridge around the base of a tooth)
- circle of Willis
- a ring of arteries at the base of the brain
- circumflex artery
- any of several paired curving arteries
- circumflex femoral vein
- either of two veins that accompany arteries of the same name serving the hip and thigh
- circumflex iliac vein
- accompanies the artery of the same name
- circumflex vein
- any of several curved parallel veins accompanying arteries of the same name
- cirrus
- a slender flexible animal appendage as on barnacles or crinoids or many insects; often tactile
- cistern
- a sac or cavity containing fluid especially lymph or cerebrospinal fluid
- clapper
- a mobile mass of muscular tissue covered with mucous membrane and located in the oral cavity
- claustrum
- a layer of grey matter in the brain adjacent to the lenticular nucleus
- clavicle
- bone linking the scapula and sternum
- claw
- sharp curved horny process on the toe of a bird or some mammals or reptiles
- claw
- a bird's foot
- cleavage
- the line formed by a groove between two parts (especially the separation between a woman's breasts)
- clenched fist
- a hand with the fingers clenched in the palm (as for hitting)
- clitoral vein
- veins that serve the clitoris
- cloaca
- (zoology) the cavity (in birds, reptiles, amphibians, most fish, and monotremes but not mammals) at the end of the digestive tract into which the intestinal, genital, and urinary tracts open
- cloven foot
- a hoof divided into two parts at its distal extremity (as of ruminants or swine)
- CNS
- the portion of the vertebrate nervous system consisting of the brain and spinal cord
- cobblers
- a man's testicles (from Cockney rhyming slang: cobbler's awl rhymes with ball)
- coccygeal nerve
- the lowest pair of spinal nerves
- coccygeal plexus
- a small plexus formed by the fifth sacral and coccygeal nerves
- coccyx
- the end of the vertebral column in humans and tailless apes
- cochlea
- the snail-shaped tube (in the inner ear coiled around the modiolus) where sound vibrations are converted into nerve impulses by the organ of Corti
- cock
- obscene terms for penis
- cockscomb
- the fleshy red crest on the head of the domestic fowl and other gallinaceous birds
- coelenteron
- the saclike body cavity of a coelenterate
- colic vein
- vein serving the large intestine
- colon
- the part of the large intestine between the cecum and the rectum; it extracts moisture from food residues before they are excreted
- column
- any tubular or pillar-like supporting structure in the body
- comb
- ciliated comb-like swimming plate of a ctenophore
- comb-plate
- a locomotor organ consisting of a row of strong cilia whose bases are fused
- commissure
- a bundle of nerve fibers passing from one side to the other of the brain or spinal cord
- common cardinal vein
- the major return channels to the heart; formed by anastomosis of the anterior and posterior cardinal veins
- common carotid
- runs upward in the neck and divides into the external and internal carotid arteries
- common facial vein
- vein formed by union of facial vein and the retromandibular vein and emptying into the jugular vein
- common iliac artery
- terminal branches of the abdominal aorta
- common iliac vein
- formed by the internal and external iliac veins; unites with its fellow from the opposite side of the body to form the inferior vena cava
- compound eye
- in insects and some crustaceans: composed of many light-sensitive elements each forming a portion of an image
- concha
- (anatomy) a structure that resembles a shell in shape
- condylar process
- the condyle of the ramus of the mandible that articulates with the skull
- condyle
- a round bump on a bone where it forms a joint with another bone
- condylion
- the craniometric point at the tip of the mandibular condyle
- conjunctiva
- a transparent lubricating mucous membrane that covers the eyeball and the under surface of the eyelid
- conjunctival layer of eyelids
- the part of the conjunctiva lining the posterior surface of the eyelids; continuous with the bulbar conjunctiva
- conjunctival veins
- veins draining the conjunctiva
- conk
- informal term for the nose
- connective tissue
- tissue of mesodermal origin consisting of e.g. collagen fibroblasts and fatty cells; supports organs and fills spaces between them and forms tendons and ligaments
- conodont
- the tiny fossil cone-shaped tooth of a primitive vertebrate of order Conodonta
- contractile organ
- a bodily organ that contracts
- convolution of Broca
- the motor speech center in the left hemisphere of the brain in most people
- convolution
- a convex fold or elevation in the surface of the brain
- cornea
- the transparent dome-shaped anterior portion of the outer covering of the eye; it covers the iris and pupil and is continuous with the sclera
- cornu
- (anatomy) any structure that resembles a horn in shape
- corona
- (anatomy) any structure that resembles a crown in shape
- coronal suture
- the suture between the parietal and frontal bones of the skull
- coronary sinus
- a short sinus receiving most of the veins of the heart; empties into the right atrium
- coronet
- margin between the skin of the pastern and the horn of the hoof
- coronion
- the craniometric point at the tip of the coronoid process of the mandible
- coronoid process of the mandible
- the coronoid process that provides an attachment for the temporal muscle
- coronoid process
- a sharp triangular process projecting from a bone
- corpus callosum
- a broad transverse nerve tract connecting the two cerebral hemispheres
- corpus geniculatum laterale
- a neural structure that serves as a processing station on the way from the retina to the occipital lobe of the cerebral cortex
- corpus geniculatum mediale
- a neural structure that serves as the last of a series of processing centers along the auditory pathway from the cochlea to the temporal lobe of the cerebral cortex
- corpus luteum
- yellow endocrine tissue that forms in a ruptured Graafian follicle following the release of an ovum; it degenerates after a few days unless pregnancy has begun
- corpus mamillare
- one of two small round structures on the undersurface of the brain that form the terminals of the anterior arches of the fornix
- corpus sternum
- the large central part of the breastbone
- corpus striatum
- a striped mass of white and grey matter located in front of the thalamus in each cerebral hemisphere; consists of the caudate nucleus and the lenticular nucleus
- cortex
- the tissue forming the outer layer of an organ or structure in plant or animal
- cortex
- the tissue that surrounds the lens nucleus
- cortical area
- any of various regions of the cerebral cortex
- corticospinal tract
- any of the important motor nerves on each side of the central nervous system that run from the sensorimotor areas of the cortex through the brainstem to motor neurons of the cranial nerve nuclei and the ventral root of the spinal cord
- costa
- a riblike part of a plant or animal (such as a middle rib of a leaf or a thickened vein of an insect wing)
- costa
- any of the 12 pairs of curved arches of bone extending from the spine to or toward the sternum in humans (and similar bones in most vertebrates)
- costal cartilage
- the cartilages that connect the sternum and the ends of the ribs; its elasticity allows the chest to move in respiration
- costal groove
- groove between the ribs where the nerves and blood vessels are
- costoaxillary vein
- one of several veins connecting intercostal veins with the lateral thoracic vein or the thoracoepigastric vein
- countenance
- the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)
- cowl muscle
- either of two flat triangular muscles of the shoulder and upper back that are involved in moving the shoulders and arms
- Cowper's gland
- either of two glands that discharge a component of seminal fluid into the urethra; homologous to Bartholin's gland in the female
- cranial cavity
- the cavity enclosed by the cranium
- cranial nerve
- any of the 12 paired nerves that originate in the brain stem
- cranial orbit
- the bony cavity in the skull containing the eyeball
- craniometric point
- a landmark on the skull from which craniometric measurements can be taken
- craw
- a pouch in many birds and some lower animals that resembles a stomach for storage and preliminary maceration of food
- crazy bone
- a point on the elbow where the ulnar nerve passes near the surface; a sharp tingling sensation results when the nerve is knocked against the bone
- crest
- a showy growth of e.g. feathers or skin on the head of a bird or other animal
- crotaphion
- the tip of the greater wing of the sphenoid bone
- crotch
- external sex organ
- croup
- the part of an animal that corresponds to the human buttocks
- crus
- the leg from the knee to foot
- crystalline lens
- biconvex transparent body situated behind the iris in the eye; its role (along with the cornea) is to focus light on the retina
- ctenidium
- comb-like respiratory structure serving as the gill of certain mollusks
- cubital nerve
- a nerve running along the inner side of the arm and passing near the elbow; supplies intrinsic muscles of the hand and the skin of the medial side of the hand
- cubitus
- the arm from the elbow to the fingertips
- cuboid bone
- the cube shaped bone on the outer side of the tarsus
- cuneiform bone
- a wrist bone that articulates with the pisiform and hamate and lunate bones
- cunt
- obscene terms for female genitals
- cupule
- a sucker on the feet of certain flies
- cusp
- a thin triangular flap of a heart valve
- cutaneous vein
- one of a number of veins in the subcutaneous tissue that empty into deep veins
- cuticle
- the dead skin at the base of a fingernail or toenail
- cutis
- a natural protective body covering and site of the sense of touch
- cyst
- a small anatomically normal sac or bladderlike structure (especially one containing fluid)
- cystic vein
- vein that drains the gallbladder
- cytoskeleton
- a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence
- cytostome
- mouth of a protozoan
- dacryocyst
- either of the two dilated ends of the lacrimal ducts at the nasal ends of the eyes that fill with tears secreted by the lacrimal glands
- dacryon
- the craniometric point at the junction of the anterior border of the lacrimal bone with the frontal bone
- dactyl
- a finger or toe in human beings or corresponding body part in other vertebrates
- decidua
- the epithelial tissue of the endometrium
- deep middle cerebral vein
- accompanies the middle cerebral artery deep in the Sylvian fissure; empties into the basal vein
- deep temporal vein
- temporal veins that empty into the pterygoid plexus
- deltoid eminence
- a bump on the outside of the humerus where the deltoid muscle attaches
- deltoid
- a large triangular muscle covering the shoulder joint and serving to abduct and flex and extend and rotate the arm
- dentate nucleus
- a large laminar nucleus of grey matter within the white matter of each cerebral hemisphere
- denticle
- small pointed ridge on the exoskeleton of an arthropod
- dentin
- bone (calcified tissue) surrounding the pulp cavity of a tooth
- depressor
- any skeletal muscle that draws a body part down
- depressor
- any nerve whose activity tends to reduce the activity or tone of the body part it serves
- descending aorta
- the descending part of the aorta that branches into the thoracic and abdominal aortae
- descending colon
- the part of the large intestine that descends from the transverse colon to the sigmoid colon
- dewlap
- a hanging fold of loose skin on an elderly person's neck
- diaphragm
- (anatomy) a muscular partition separating the abdominal and thoracic cavities; functions in respiration
- diaphysis
- the main (mid) section of a long bone
- digestive gland
- any gland having ducts that pour secretions into the digestive tract
- digestive system
- the system that makes food absorbable into the body
- digital vein
- one of the veins serving the fingers or toes
- dilator
- a muscle or nerve that dilates or widens a body part
- diploic vein
- one of the veins serving the spongy part of the cranial bones
- dock
- the solid bony part of the tail of an animal as distinguished from the hair
- dorsal fin
- unpaired median fin on the backs of fishes and some other aquatic vertebrates that help to maintain balance
- dorsal horn
- one of two roots of a spinal nerve that passes dorsally from the spinal cord and that consists of sensory fibers
- dorsal scapular vein
- vein that is a tributary of the subclavian vein or external jugular vein and accompanies the descending scapular artery
- dorsal vertebra
- one of 12 vertebrae in the human vertebral column; thoracic vertebrae extend from the seventh cervical vertebra down to the first lumbar vertebra
- dorsum
- the back of the body of a vertebrate or any analogous surface (as the upper or outer surface of an organ or appendage or part)
- duct gland
- a gland that secretes externally through a duct
- ductless gland
- any of the glands of the endocrine system that secrete hormones directly into the bloodstream
- ductule
- a very small duct
- ductus arteriosus
- a blood vessel in a fetus that bypasses pulmonary circulation by connecting the pulmonary artery directly to the ascending aorta; normally closes at birth
- ductus deferens
- a duct that carries spermatozoa from the epididymis to the ejaculatory duct
- dug
- an udder or breast or teat
- duodenum
- the part of the small intestine between the stomach and the jejunum
- dura
- the outermost (and toughest) of the 3 meninges
- ear
- the sense organ for hearing and equilibrium
- ear lobe
- the fleshy pendulous part of the external human ear
- eardrum
- the membrane in the ear that vibrates to sound
- eccrine gland
- a small sweat gland that produces only a fluid; restricted to the human skin
- ectoblast
- the outer germ layer that develops into skin and nervous tissue
- effector
- an organ (a gland or muscle) that becomes active in response to nerve impulses
- efferent
- a nerve that conveys impulses toward or to muscles or glands
- ejaculatory duct
- a part of the seminal duct formed by the duct from the seminal vesicle and the vas deferens; passes through the prostate gland
- elastic tissue
- connective tissue consisting chiefly of elastic fibers found in the dermis of the skin and in the walls of veins and arteries and in some tendons and ligaments
- elbow
- the joint of a mammal or bird that corresponds to the human elbow
- elbow bone
- the inner and longer of the two bones of the human forearm
- elytron
- either of the horny front wings in beetles and some other insects which cover and protect the functional hind wings
- embryonic tissue
- tissue in an embryo
- eminence
- a protuberance on a bone especially for attachment of a muscle or ligament
- emissary vein
- one of several connecting veins in the scalp and head that drain blood from sinuses in the dura mater to veins outside the skull
- enation
- a natural projection or outgrowth from a plant body or organ
- end organ
- a specialized structure at the peripheral end of some motor or sensory nerve fibers
- endoblast
- the inner germ layer that develops into the lining of the digestive and respiratory systems
- endocardium
- the membrane that lines the cavities of the heart and forms part of the heart valves
- endocranium
- membrane lining the inside of the skull
- endocrine system
- the system of glands that produce endocrine secretions that help to control bodily metabolic activity
- endometrium
- (pregnancy) the mucous membrane that lines the uterus; thickens under hormonal control and (if pregnancy does not occur) is shed in menstruation; if pregnancy occurs it is shed along with the placenta at parturition
- endoneurium
- delicate connective tissue around individual nerve fibers in nerve
- endoskeleton
- the internal skeleton; bony and cartilaginous structure (especially of vertebrates)
- endosteum
- vascular membrane that lines the inner surface of long bones
- endothelium
- an epithelium of mesoblastic origin; a thin layer of flattened cells that lines the inside of some body cavities
- endplate
- the flattened end of a motor neuron that transmits neural impulses to a muscle
- energid
- a biological unit consisting of a nucleus and the body of cytoplasm with which it interacts
- enteroceptor
- any receptor that responds to stimuli inside the body
- enteron
- the alimentary canal (especially of an embryo or a coelenterate)
- entomion
- the craniometric point at the tip of the angular part of the parietal bone that articulates with the temporal bone
- entrails
- internal organs collectively (especially those in the abdominal cavity)
- ependyma
- thin epithelial membrane lining the ventricles of the brain and the spinal cord canal
- epicanthic fold
- a vertical fold of skin over the nasal canthus; typical for many east Asian peoples; sometimes occurs in Down's syndrome
- epicardia
- the short part of the esophagus extending downward from the diaphragm to the stomach
- epicardium
- the innermost of the two layers of the pericardium
- epicondyle
- a projection on a bone above a condyle serving for the attachment of muscles and ligaments
- epididymis
- a convoluted tubule in each testis; carries sperm to vas deferens
- epigastric fossa
- a slight depression in the midline just below the sternum (where a blow can affect the solar plexus)
- epigastric vein
- veins serving the anterior walls of the abdomen
- epigastrium
- the region lying on or over the stomach (just below the sternum)
- epiglottis
- a flap of cartilage that covers the windpipe while swallowing
- epiphysis
- the end of a long bone; initially separated from the main bone by a layer of cartilage that eventually ossifies so the parts become fused
- epiphysis
- a small endocrine gland in the brain; situated beneath the back part of the corpus callosum; secretes melatonin
- episcleral veins
- small veins in the sclera near the corneal margin; empty into the anterior ciliary veins
- epithelial tissue
- membranous tissue covering internal organs and other internal surfaces of the body
- erectile organ
- an organ containing erectile tissue
- erectile tissue
- vascular tissue capable of filling with blood and becoming rigid
- erogenous zone
- any area of the body especially sensitive to sexual stimulation
- esophageal veins
- small veins from the esophagus emptying into the brachiocephalic vein or the azygos veins
- esophagus
- the passage between the pharynx and the stomach
- ethmoid sinus
- a sinus of the meatuses of the nasal cavity (behind the bridge of the nose)
- ethmoid
- one of the eight bones of the cranium; a small bone filled with air spaces that forms part of the eye sockets and the nasal cavity
- ethmoidal vein
- veins that drain the ethmoidal sinuses and empty into the superior ophthalmic vein
- Eustachian tube
- either of the paired tubes connecting the middle ears to the nasopharynx; equalizes air pressure on the two sides of the eardrum
- excrescence
- (pathology) an abnormal outgrowth or enlargement of some part of the body
- excretory organ
- an organ that separates waste substances from the blood and discharges them
- exoskeleton
- the exterior protective or supporting structure or shell of many animals (especially invertebrates) including bony or horny parts such as nails or scales or hoofs
- extensor
- a skeletal muscle whose contraction extends or stretches a body part
- external body part
- any body part visible externally
- external carotid
- the branch of the carotid artery that supplies blood to the face and tongue and external parts of the head
- external ear
- the part of the ear visible externally
- external gill
- occurs in some mollusks and in tadpoles and other immature amphibians
- external iliac artery
- the outer branch of the common iliac artery on either side of the body; becomes the femoral artery
- external iliac vein
- a continuation of the femoral vein; unites with the internal iliac vein to form the common iliac vein
- external jugular vein
- formed by the junction of the posterior auricular and the retromandibular veins; empties into the subclavian vein
- external nasal vein
- one of the veins that drain the external nose and empty into the angular or facial vein
- external organ
- an organ that is situated on or near the surface of the body
- external orifice
- the orifice through which urine is discharged
- exteroceptor
- any receptor that responds to stimuli outside the body
- extremity
- that part of a limb that is farthest from the torso
- eye muscle
- one of the small muscles of the eye that serve to rotate the eyeball
- eye
- the organ of sight
- eyeball
- the ball-shaped capsule containing the vertebrate eye
- eyecup
- (embryology) a two-walled cuplike depression that develops into the pigmented and sensory layers of the retina
- eyelid
- either of two folds of skin that can be moved to cover or open the eye
- face
- the part of an animal corresponding to the human face
- face
- the front of the human head from the forehead to the chin and ear to ear
- facia
- a sheet or band of fibrous connective tissue separating or binding together muscles and organs etc
- facial muscle
- any of the skeletal muscles of the face
- facial vein
- any of several veins draining the face
- facial
- cranial nerve that supplies facial muscles
- falciform ligament
- a ligament that attaches part of the liver to the diaphragm and the abdominal wall
- fallen arch
- an instep flattened so the entire sole rests on the ground
- Fallopian tube
- either of a pair of tubes conducting the egg from the ovary to the uterus
- false glottis
- the opening between the false vocal folds
- false vocal cord
- either of the upper two vocal cords that are not involved in vocalization
- family jewels
- external male sex organs
- fang
- hollow or grooved tooth of a venomous snake; used to inject its poison
- fang
- canine tooth of a carnivorous animal; used to seize and tear its prey
- fang
- an appendage of insects that is capable of injecting venom; usually evolved from the legs
- fanny
- external female sex organs
- fascicle
- a bundle of fibers (especially nerve fibers)
- fauces
- the passage between the back of the mouth and the pharynx
- faucial tonsil
- either of two masses of lymphatic tissue one on each side of the oral pharynx
- feature
- the characteristic parts of a person's face: eyes and nose and mouth and chin
- female internal reproductive organ
- the reproductive organs of a woman
- female reproductive system
- the reproductive system of females
- femoral biceps
- the biceps muscle of the thigh; it flexes the knee and rotates the leg laterally
- femoral vein
- a vein that accompanies the femoral artery in the same sheath; a continuation of the popliteal vein; becomes the external iliac vein
- femoris
- the longest and thickest bone of the human skeleton; extends from the pelvis to the knee
- fenestra
- a small opening covered with membrane (especially one in the bone between the middle and inner ear)
- fenestra cochleae
- fenestra leading into the cochlea
- fenestra of the vestibule
- fenestra that has the base of the stapes attached to it
- fertilization membrane
- the membrane that forms around a fertilized ovum and prevents penetration by additional spermatozoon
- fetal circulation
- the system of blood vessels and structures through which blood moves in a fetus
- fetal membrane
- any membrane that functions for the protection or nourishment or respiration or excretion of a developing fetus
- fetlock
- projection behind and above a horse's hoof
- fetlock
- the joint between the cannon bone and the pastern
- fetter bone
- the part between the fetlock and the hoof
- fibrocartilage
- cartilage that is largely composed of fibers like those in ordinary connective tissue
- fibrous joint
- an immovable joint (especially between the bones of the skull)
- fibrous tissue
- tissue consisting of or containing fibers in both animals and plants
- fibular vein
- accompany the peroneal arteries; arising in the heel and running up the back of the leg to join the posterior tibial veins of the popliteal vein
- fifth cranial nerve
- the main sensory nerve of the face and motor nerve for the muscles of mastication
- filament
- a threadlike structure (as a chainlike series of cells)
- fillet
- a bundle of sensory nerve fibers going to the thalamus
- fimbria
- thin projections forming a fringe (especially around the ovarian end of the Fallopian tube)
- fin
- organ of locomotion and balance in fishes and some other aquatic animals
- finger
- any of the terminal members of the hand (sometimes excepting the thumb)
- fingernail
- the nail at the end of a finger
- first cranial nerve
- a collective term for numerous olfactory filaments in the nasal mucosa
- first stomach
- the first compartment of the stomach of a ruminant; here food is collected and returned to the mouth as cud for chewing
- fishbone
- a bone of a fish
- fissure
- (anatomy) a long narrow slit or groove that divides an organ into lobes
- fissure of Rolando
- a brain fissure extending upward on the lateral surface of both hemispheres; separates the frontal and parietal lobes
- fissure of Sylvius
- the deepest and most prominent of the cortical fissures; separates the frontal lobes and temporal lobes in both hemispheres
- fistula
- an abnormal passage leading from a suppurating cavity to the body surface
- flab
- loose or flaccid body fat
- flag
- a conspicuously marked or shaped tail
- flagellum
- a lash-like appendage used for locomotion (e.g., in sperm cells and some bacteria and protozoa)
- flame cell
- organ of excretion in flatworms
- flank
- the side between ribs and hipbone
- flap
- a movable piece of tissue partly connected to the body
- flatfoot
- a foot afflicted with a fallen arch; abnormally flattened and spread out
- flesh
- the soft tissue of the body of a vertebrate: mainly muscle tissue and fat
- flexor
- a skeletal muscle whose contraction bends a joint
- flipper
- the flat broad limb of aquatic animals specialized for swimming
- fluke
- either of the two lobes of the tail of a cetacean
- fold
- a folded part (as in skin or muscle)
- follicle
- any small spherical group of cells containing a cavity
- fontanel
- any membranous gap between the bones of the cranium in an infant or fetus
- foot
- the part of the leg of a human being below the ankle joint
- foot
- any of various organs of locomotion or attachment in invertebrates
- fore wing
- either of the anterior pair of wings on an insect that has four wings
- forearm
- the part of the superior limb between the elbow and the wrist
- forebrain
- the anterior portion of the brain; the part of the brain that develops from the anterior part of the neural tube
- forefinger
- the finger next to the thumb
- forefoot
- a front foot of a quadruped
- forehead
- the large cranial bone forming the front part of the cranium: includes the upper part of the orbits
- foreleg
- the forelimb of a quadruped
- forelimb
- the front limb (or the homologous structure in other animals, such as a flipper or wing)
- forepaw
- front paw; analogous to the human hand
- foreskin
- a fold of skin covering the tip of the penis
- foreskin
- a fold of skin covering the tip of the clitoris
- fornix
- generally any arch shaped structure (but often it refers to the arched roof of an anatomical space)
- fornix
- an arched bundle of white fibers at the base of the brain by which the hippocampus of each hemisphere projects to the contralateral hippocampus and to the thalamus and mamillary bodies
- fossa
- a concavity in a surface (especially an anatomical depression)
- fossorial foot
- foot adapted for digging as in moles
- fourth cranial nerve
- either of the two cranial nerves on either side that control the superior oblique muscles of the eyes
- fourth ventricle
- an irregular ventricle between the third ventricle and the central canal of the spinal cord
- fovea
- area consisting of a small depression in the retina containing cones and where vision is most acute
- frame
- the hard structure (bones and cartilages) that provides a frame for the body of an animal
- frill
- (paleontology) a bony plate that curves upward behind the skull of many ceratopsian dinosaurs
- frill
- an external body part consisting of feathers or hair about the neck of a bird or other animal
- frontal cortex
- that part of the cerebral cortex in either hemisphere of the brain lying directly behind the forehead
- frontal gyrus
- any of the convolutions of the outer surface of the frontal lobe of the cerebrum
- frontal sinus
- one of a pair of cavities in the frontal bone
- frontal suture
- the suture between two halves of the frontal bone (usually obliterated by the age of 6)
- fundus
- (anatomy) the base of a hollow organ or that part of the organ farthest from its opening
- funiculus
- any of several body structure resembling a cord
- furcula
- a forked bone formed by the fusion of the clavicles of most birds
- fuzz
- filamentous hairlike growth on a plant
- gall bladder
- a muscular sac attached to the liver that stores bile (secreted by the liver) until it is needed for digestion
- ganglion
- an encapsulated neural structure consisting of a collection of cell bodies or neurons
- gaskin
- lower part of a horse's thigh between the hock and the stifle
- gastric mill
- thick-walled muscular pouch below the crop in many birds and reptiles for grinding food
- gastric vein
- one of several veins draining the stomach walls
- gastrocnemius
- the muscle in the back part of the leg that forms the greater part of the calf; responsible for the plantar flexion of the foot
- gastroepiploic vein
- one of two veins serving the great curvature of the stomach
- genicular vein
- veins that drain blood from structures around the knee; empty into the popliteal vein
- geniculate body
- one of four small oval masses that protrude slightly from the underside of the thalamus and function as synaptic centers on the way to the cerebral cortex
- genital system
- organs and tissues involved in the production and maturation of gametes and in their union and subsequent development as offspring
- germ
- a small apparently simple structure (as a fertilized egg) from which new tissue can develop into a complete organism
- germ layer
- (embryology) any of the 3 layers of cells differentiated in embryos following gastrulation
- GI tract
- tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination
- gingiva
- the tissue (covered by mucous membrane) of the jaws that surrounds the bases of the teeth
- ginglymoid joint
- a freely moving joint in which the bones are so articulated as to allow extensive movement in one plane
- girdle
- an encircling or ringlike structure
- glabella
- a smooth prominence of the frontal bone between and above the eyebrows; the most forward projecting point of the forehead in the midline at the level of the supraorbital ridges
- gland
- any of various organs that synthesize substances needed by the body and release it through ducts or directly into the bloodstream
- glandulae sebaceae
- a cutaneous gland that secretes sebum (usually into a hair follicle) for lubricating hair and skin
- glans
- a small rounded structure; especially that at the end of the penis or clitoris
- glans clitoridis
- small mass of erectile tissue at the end of the body of the clitoris
- glans penis
- the conical mass of erectile tissue that forms the head of the penis
- glenoid cavity
- the concavity in the head of the scapula that receives the head of the humerus to form the shoulder joint
- glenoid fossa
- a deep concavity in the temporal bone at the root of the zygomatic arch that receives the condyle of the mandible
- glia
- sustentacular tissue that surrounds and supports neurons in the central nervous system; glial and neural cells together compose the tissue of the central nervous system
- globus pallidus
- the inner pale yellow part of the lenticular nucleus
- glochid
- a barbed spine or bristle (often tufted on cacti)
- glomerulus
- a small intertwined group of capillaries in the malpighian body; it filters the blood during urine formation
- glossopharyngeal nerve
- sensory nerve to the pharynx and back of the tongue; motor fibers innervate muscles that elevate the pharynx and larynx; includes parasympathetic fibers to the otic ganglion
- glottis
- the vocal apparatus of the larynx; the true vocal folds and the space between them where the voice tone is generated
- glottis vera
- the space between the two true vocal folds
- glute
- any one of three large skeletal muscles that form the buttock and move the thigh
- gluteal vein
- veins draining the gluteal muscles on either side of the body
- gluteus maximus
- the outermost of the three gluteal muscles
- gluteus medius
- the middle of the three gluteal muscles
- gluteus minimus
- the innermost of the three gluteal muscles
- gnathion
- the most inferior point of the mandible in the midline
- Golgi apparatus
- a netlike structure in the cytoplasm of animal cells (especially in those cells that produce secretions)
- gonad
- a gland in which gametes (sex cells) are produced
- gonion
- the craniometric point on either side at the apex of the lower jaw
- Graafian follicle
- a vascular body in a mammalian ovary enclosing a developing egg
- graft
- (surgery) tissue or organ transplanted from a donor to a recipient; in some cases the patient can be both donor and recipient
- granulation
- new connective tissue and tiny blood vessels that form on the surfaces of a wound during the healing process
- gray matter
- greyish nervous tissue containing cell bodies as well as fibers; forms the cerebral cortex consisting of unmyelinated neurons
- great adductor muscle
- the muscle that adducts and extends the thigh
- great cerebral vein
- a cerebral vein formed by the two internal cerebral veins and continuing into the sinus rectus
- great saphenous vein
- the longest vein in the body; runs from foot to the groin where it joins the femoral vein
- greater pectoral muscle
- a skeletal muscle that adducts and rotates the arm
- greater peritoneal sac
- the interior of the peritoneum; a potential space between layers of the peritoneum
- greater rhomboid muscle
- rhomboid muscle that draws the scapula toward the spinal column
- green gland
- one of a pair of glands (believed to have excretory functions) in some crustaceans near the base of the large antennae
- grinder
- grinding tooth with a broad crown; located behind the premolars
- groin
- the crease at the junction of the inner part of the thigh with the trunk together with the adjacent region and often including the external genitals
- groove
- (anatomy) any furrow or channel on a bodily structure or part
- gustatory organ
- an oval sensory end organ on the surface of the tongue
- haemal arch
- a structure arising ventrally from a vertebral centrum and enclosing the caudal blood vessels
- hair
- a filamentous projection or process on an organism
- hair follicle
- a small tubular cavity containing the root of a hair; small muscles and sebaceous glands are associated with them
- hair
- any of the cylindrical filaments characteristically growing from the epidermis of a mammal
- half-moon
- the crescent-shaped area at the base of the human fingernail
- hamate
- the wrist bone in line with the 4th and 5th fingers
- hammer
- the ossicle attached to the eardrum
- hammertoe
- a deformed toe which is bent in a clawlike arch
- hamstring
- one of the tendons at the back of the knee
- hand
- terminal part of the forelimb in certain vertebrates (e.g. apes or kangaroos)
- hand
- the (prehensile) extremity of the superior limb
- haunch
- the hip and buttock and upper thigh in human beings
- haunch
- the loin and leg of a quadruped
- haustorium
- a root-like attachment in parasitic plants that penetrates and obtains food from the host
- Haversian canal
- any of the many tiny canals that contain blood vessels and connective tissue and that form a network in bone
- haw
- the nictitating membrane of a horse
- hawk nose
- a nose curved downward like the beak of a hawk
- head
- the rounded end of a bone that fits into a rounded cavity in another bone to form a joint
- head
- that part of a skeletal muscle that is away from the bone that it moves
- heart ventricle
- a chamber of the heart that receives blood from an atrium and pumps it to the arteries
- heart
- the hollow muscular organ located behind the sternum and between the lungs; its rhythmic contractions move the blood through the body
- heel
- the back part of the human foot
- hemizygos vein
- a continuation of the left ascending lumbar vein; crosses the midline at the 8th vertebra and empties into the azygos vein
- hemorrhoidal vein
- any of several veins draining the walls of the anal canal and rectum
- hepatic duct
- the duct that drains bile from the liver
- hepatic lobe
- any of the five lobes forming the liver
- hepatic portal vein
- a short vein that carries blood into the liver
- hepatic vein
- a vein that drains the liver; empties into the vena cava
- heterocercal fin
- a tail fin with unequal lobes in which the vertebral column turns upward into the larger lobe as in sharks
- heterodactyl foot
- a bird's foot having the first and second toes of each foot directed backward and the third and fourth forward
- heterograft
- tissue from an animal of one species used as a temporary graft (as in cases of severe burns) on an individual of another species
- hilum
- (anatomy) a depression or fissure where vessels or nerves or ducts enter a bodily organ
- hind leg
- the back limb of a quadruped
- hind limb
- a posterior appendage such as a leg or the homologous structure in other animals
- hindbrain
- the posterior portion of the brain including cerebellum and brainstem
- hindfoot
- a rear foot of a quadruped
- hindgut
- the caudal part of the alimentary canal in vertebrate embryos
- hip
- either side of the body below the waist and above the thigh
- hip socket
- the socket part of the ball-and-socket joint between the head of the femur and the innominate bone
- hip
- the structure of the vertebrate skeleton supporting the lower limbs in humans and the hind limbs or corresponding parts in other vertebrates
- hipbone
- large flaring bone forming one half of the pelvis; made up of the ilium and ischium and pubis
- hippocampus
- a complex neural structure (shaped like a sea horse) consisting of grey matter and located on the floor of each lateral ventricle; intimately involved in motivation and emotion as part of the limbic system; has a central role in the formation of memories
- hock
- tarsal joint of the hind leg of hoofed mammals; corresponds to the human ankle
- homocercal fin
- symmetrical tail fin extending beyond the end of the vertebral column as in most bony fishes
- hood
- (zoology) an expandable part or marking that resembles a hood on the head or neck of an animal
- hoof
- the foot of an ungulate mammal
- hoof
- the horny covering of the end of the foot in ungulate mammals
- hooks
- large strong hand (as of a fighter)
- horn
- any hard protuberance from the head of an organism that is similar to or suggestive of a horn
- horn
- one of the bony outgrowths on the heads of certain ungulates
- horny structure
- any rigid body structure composed primarily of keratin
- horse's foot
- the hoof of a horse
- horseback
- the back of a horse
- human head
- the head of a human being
- humerus
- bone extending from the shoulder to the elbow
- hyaline cartilage
- translucent cartilage that is common in joints and the respiratory passages; forms most of the fetal skeleton
- hyaloid
- the transparent membrane enveloping the vitreous humor of the eye and separating it from the retina
- hymen
- a fold of tissue that partly covers the entrance to the vagina of a virgin
- hyoid
- a U-shaped bone at the base of the tongue that supports the tongue muscles
- hypochondrium
- the upper region of the abdomen just below the lowest ribs on either side of the epigastrium
- hypodermis
- layer of cells that secretes the chitinous cuticle in e.g. arthropods
- hypogastric artery
- the inner branch of the common iliac artery on either side of the body; divides into several branches that supply blood to the pelvic and gluteal areas
- hypogastric plexus
- a plexus of nerves serving the pelvic viscera
- hypogastric vein
- a vein that unites with the external iliac vein to form the common iliac vein
- hypoglossal
- supplies intrinsic muscles of the tongue and other tongue muscles
- hypophyseal stalk
- the funnel-shaped stalk connecting the pituitary gland to the hypothalamus
- hypophysis
- the master gland of the endocrine system; located at the base of the brain
- hypothalamus
- a basal part of the diencephalon governing autonomic nervous system
- ileocecal valve
- valve between the ileum of the small intestine and the cecum of the large intestine; prevents material from flowing back from the large to the small intestine
- ileocolic vein
- a vein that drains the end of the ileum and the appendix and the cecum and the lower part of the ascending colon
- ileum
- the part of the small intestine between the jejunum and the cecum
- iliac vein
- one of three veins draining the pelvic area
- iliolumbar vein
- a branch of the internal iliac vein
- ilium
- the upper and widest of the three bones making up the hipbone
- immune system
- a system (including the thymus and bone marrow and lymphoid tissues) that protects the body from foreign substances and pathogenic organisms by producing the immune response
- imperforate anus
- a congenital defect of the anus; there is partial or complete obstruction of the anal opening
- imperforate hymen
- hymen that is completely closed so that menstrual blood cannot flow out
- incisor
- a tooth for cutting or gnawing; located in the front of the mouth in both jaws
- incompetent cervix
- (obstetrics) uterine cervix that becomes dilated before term and without labor often resulting in miscarriage or premature birth
- inferior cerebellar artery
- the inferior branch of the cerebellar artery
- inferior cerebral vein
- veins that drain the undersurface of the cerebral hemispheres and empty into the cavernous and transverse sinuses
- inferior colliculus
- an essential auditory center in the midbrain
- inferior epigastric vein
- empties into the external iliac vein
- inferior labial vein
- a tributary of the facial vein that drains the lower lip
- inferior mesenteric artery
- arises near the lower end of the aorta and supplies the large intestine
- inferior ophthalmic vein
- a vein that drains a venous network in the floor and medial wall of the eye socket
- inferior pulmonary vein
- either of two pulmonary veins (left and right) returning blood from the inferior lobes of the lungs
- inferior rectus
- the ocular muscle whose contraction turns the eyeball down and medially
- inferior thalamostriate vein
- tributaries to the basal vein
- inferior thyroid vein
- any of several veins on each side that drain the thyroid gland and empty into the innominate vein
- inferior vena cava
- receives blood from lower limbs and abdominal organs and empties into the posterior part of the right atrium of the heart; formed from the union of the two iliac veins
- inferior vocal cord
- either of the two lower vocal folds that come together to form the glottis; produce a vocal tone when they are approximated and air from the lungs passes between them
- infundibulum
- any of various funnel-shaped parts of the body (but especially the hypophyseal stalk)
- ingrown hair
- a hair that does not emerge from the follicle but remains embedded in the skin (usually causing inflammation)
- ingrown toenail
- toenail having its free tip or edges embedded in the surrounding flesh
- inion
- the craniometric point that is the most prominent point at the back of the head (at the occipital protuberance)
- inner ear
- a complex system of interconnecting cavities; concerned with hearing and equilibrium
- innominate artery
- a large artery arising from the arch of the aorta and divides into the right subclavian artery and the right common carotid artery; supplies the right side of the neck and head and the right shoulder and arm
- instep
- the arch of the foot
- integumentary system
- the skin and its appendages
- intercapitular vein
- veins connecting the dorsal and palmar veins of the hand or the dorsal and plantar veins of the foot
- intercostal vein
- several veins draining the intercostal spaces of the rib cage
- intercostal
- muscles between the ribs; they contract during inspiration
- intermaxillary suture
- the suture between the two maxillae of the upper jawbone
- internal auditory vein
- veins that drain the inner ear
- internal carotid artery
- the branch of the carotid artery that supplies blood to the brain and eyes and internal parts of the head
- internal cerebral vein
- two paired veins passing caudally near the midline and uniting to form the great cerebral vein
- internal jugular vein
- a continuation of the sigmoid sinus of the dura mater; joins the subclavian vein to form the brachiocephalic vein
- internal maxillary artery
- the maxillary artery that supplies deep structure of the face and some of the meninges
- internal organ
- a main organ that is situated inside the body
- internasal suture
- the suture between the two nasal bones
- interparietal suture
- the suture uniting the two parietal bones
- interphalangeal joint
- any of the joints between the phalanges of the fingers or toes
- interstice
- a small structural space between tissues or parts of an organ
- interstitial tissue
- tissue between the cells of a structure or part in plant or animal
- intervertebral vein
- one of several veins accompanying spinal nerves
- intestinal artery
- an artery that is a branch of the superior mesenteric artery that supplies the jejunum
- intima
- the innermost membrane of an organ (especially the inner lining of an artery or vein or lymphatic vessel)
- introitus
- entrance or opening to a hollow organ or tube (especially the vaginal opening)
- investment
- outer layer or covering of an organ or part or organism
- involuntary muscle
- a muscle that contracts without conscious control and found in walls of internal organs such as stomach and intestine and bladder and blood vessels (excluding the heart)
- iris
- muscular diaphragm that controls the size of the pupil which in turn controls the amount of light that enters the eye; it forms the colored portion of the eye
- ischial bone
- one of the three sections of the hipbone; situated below the ilium
- islands of Langerhans
- cell clusters in the pancreas that form the endocrine part of that organ; secrete insulin and other hormones
- jaw
- the part of the skull of a vertebrate that frames the mouth and holds the teeth
- jaw
- the bones of the skull that frame the mouth and serve to open it; the bones that hold the teeth
- jawbone
- the jaw in vertebrates that is hinged to open the mouth
- jejunum
- the part of the small intestine between the duodenum and the ileum
- jowl
- a fullness and looseness of the flesh of the lower cheek and jaw (characteristic of aging)
- jugal point
- the craniometric point at the union of the frontal and temporal processes of the zygomatic bone
- jugular
- veins in the neck that return blood from the head
- keel
- the median ridge on the breastbone of birds that fly
- kidney
- either of two bean-shaped excretory organs that filter wastes (especially urea) from the blood and excrete them and water in urine
- knee
- joint between the femur and tibia in a quadruped; corresponds to the human knee
- kneecap
- a small flat triangular bone in front of the knee that protects the knee joint
- knuckle
- a joint of a finger when the fist is closed
- labia majora
- the two outer folds of the vulva
- labia minora
- the two inner folds of the vulva
- labial vein
- a vein draining the lips of the mouth
- labial vein
- veins draining the lips of the vulva
- labium
- a liplike structure that bounds a bodily orifice (especially any of the four labiate folds of a woman's vulva)
- lachrymal duct
- any of several small ducts that carry tears from the lacrimal glands
- lachrymal gland
- any of the glands in the eyes that secrete tears
- lacrimal apparatus
- the structures that secrete and drain tears from the eye
- lacrimal bone
- small fragile bone making up part of the front inner walls of each eye socket and providing room for the passage of the lacrimal ducts
- lacrimal vein
- drains the lacrimal gland; empties into the superior ophthalmic vein
- lacteal
- any of the lymphatic vessels that convey chyle from the small intestine to the thoracic duct
- lactiferous duct
- ducts of the mammary gland that carry milk to the nipple
- lambda
- the craniometric point at the junction of the sagittal and lamboid sutures of the skull
- lamboid suture
- the suture between the occipital and parietal bones
- lamella
- a thin membrane that is one of the calcified layers that form bones
- lamina
- a thin plate or layer (especially of bone or mineral)
- lamina arcus vertebrae
- lamina of the vertebral arch; the flattened posterior part of the vertebral arch from which the spinous process extends
- landmark
- an anatomical structure used as a point of origin in locating other anatomical structures (as in surgery) or as point from which measurements can be taken
- language area
- a large cortical area (in the left hemisphere in most people) containing all the centers associated with language
- lantern jaw
- a long thin lower jaw
- lap
- the upper side of the thighs of a seated person
- lappet
- a fleshy wrinkled and often brightly colored fold of skin hanging from the neck or throat of certain birds (chickens and turkeys) or lizards
- large intestine
- beginning with the cecum and ending with the rectum; includes the cecum and the colon and the rectum; extracts moisture from food residues which are later excreted as feces
- laryngeal vein
- one of two veins draining the larynx
- laryngopharynx
- the lower part of the pharynx
- larynx
- a cartilaginous structure at the top of the trachea; contains elastic vocal cords that are the source of the vocal tone in speech
- lat
- a broad flat muscle on either side of the back
- lateral condyle
- a condyle on the outer side of the lower extremity of the femur
- lateral epicondyle
- epicondyle near the lateral condyle of the femur
- lateral line
- sense organs of fish and amphibians; believed to detect pressure changes in the water
- lateral ventricle
- either of two horseshoe-shaped ventricles one in each cerebral hemisphere; they communicate with the third ventricle via the foramen of Monro
- layer
- thin structure composed of a single thickness of cells
- leaf node
- (botany) the small swelling that is the part of a plant stem from which one or more leaves emerge
- left brain
- the cerebral hemisphere to the left of the corpus callosum that controls the right half of the body
- left coronary artery
- arises from the left aortic sinus; supplies the left side of the heart
- left gastric vein
- arises from a union of veins from the gastric cardia; runs in the lesser omentum; empties into the portal vein
- left ventricle
- the chamber on the left side of the heart that receives arterial blood from the left atrium and pumps it into the aorta
- left
- the hand that is on the left side of the body
- leg
- a human limb; commonly used to refer to a whole limb but technically only the part of the limb between the knee and ankle
- leg
- a structure in animals that is similar to a human leg and used for locomotion
- leg bone
- a bone of the leg
- lens capsule
- a tenuous mesoblastic membrane surrounding the lens of the eye
- lens nucleus
- the central structure of the lens that is surrounded by the cortex
- lenticular nucleus
- a basal ganglion shaped like a lens and including the outer reddish putamen and the inner pale yellow pallidum
- leptomeninges
- the two innermost layers of the meninges; cerebrospinal fluid circulates between these innermost layers
- lesser omentum
- a part of the peritoneum attached to the stomach and liver and supporting the hepatic vessels
- lesser rhomboid muscle
- rhomboid muscle that draws the scapula toward the vertebral column and slightly upward
- levator
- a muscle that serves to lift some body part (as the eyelid or lip)
- lien
- a large dark-red oval organ on the left side of the body between the stomach and the diaphragm; produces cells involved in immune responses
- ligament
- a sheet or band of tough fibrous tissue connecting bones or cartilages or supporting muscles or organs
- ligamentum teres uteri
- ligament attached to the uterus on either side in front of and below the opening of the Fallopian tube and passing through the inguinal canal to the labia majora
- limb
- one of the jointed appendages of an animal used for locomotion or grasping: arm; leg; wing; flipper
- limbic brain
- a system of functionally related neural structures in the brain that are involved in emotional behavior
- limbus
- a border or edge of any of various body parts distinguished by color or structure
- lingual vein
- a vein that receives blood from the tongue and the floor of the mouth and empties into the internal jugular or the facial vein
- lip
- either of two fleshy folds of tissue that surround the mouth and play a role in speaking
- liposome
- an artificially made microscopic vesicle into which nucleic acids can be packaged; used in molecular biology as a transducing vector
- little finger
- the finger farthest from the thumb
- little toe
- the fifth smallest outermost toe
- liver
- large and complicated reddish-brown glandular organ located in the upper right portion of the abdominal cavity; secretes bile and functions in metabolism of protein and carbohydrate and fat; synthesizes substances involved in the clotting of the blood; synthesizes vitamin A; detoxifies poisonous substances and breaks down worn-out erythrocytes
- lobate foot
- a bird's foot having separate toes each with membranous flaps along the sides
- lobe
- (anatomy) a somewhat rounded subdivision of a bodily organ or part
- lobe of the lung
- any of the three lobes of the right lung or the two lobes of the left lung
- lobule
- a small lobe or subdivision of a lobe
- locule
- a small cavity or space within an organ or in a plant or animal
- locus niger
- a layer of deeply pigmented grey matter in the midbrain; associated with the striate body; is involved in metabolic disturbances associated with Parkinson's disease and with Huntington's disease
- loin
- either side of the backbone between the hipbone and the ribs in humans as well as quadrupeds
- loins
- the region of the hips and groin and lower abdomen
- loins
- the lower part of the abdomen just above the external genital organs
- long bone
- in limbs of vertebrate animals: a long cylindrical bone that contains marrow
- love handle
- excess fat around the waistline
- lower respiratory tract
- the bronchi and lungs
- lumbar nerve
- any of five pairs of spinal nerves emerging from the lumbar section of the spinal cord
- lumbar plexus
- a plexus of nerves formed by the ventral branches of the first four lumbar nerves
- lumbar plexus
- a lymphatic plexus located along the lower portion of the aorta and iliac vessels
- lumbar vein
- veins that drain the posterior body wall and the lumbar vertebral venous plexuses
- lumbar vertebra
- one of 5 vertebrae in the human vertebral column; lumbar vertebrae extend from the twelfth thoracic vertebra down to the sacral vertebrae
- lumbosacral plexus
- a nerve plexus formed by the ventral divisions of the coccygeal and sacral and lumbar nerves; supplies the lower limbs and perineum and coccygeal area
- lumen
- a cavity or passage in a tubular organ
- lunate bone
- one of the eight small wrist bones
- lung
- either of two saclike respiratory organs in the chest of vertebrates; serves to remove carbon dioxide and provide oxygen to the blood
- Luschka's tonsil
- a collection of lymphatic tissue in the throat behind the uvula (on the posterior wall and roof of the nasopharynx)
- lymph gland
- the source of lymph and lymphocytes
- lymph vessel
- a vascular duct that carries lymph which is eventually added to the venous blood circulation
- lymphatic system
- the interconnected system of spaces and vessels between body tissues and organs by which lymph circulates throughout the body
- lymphatic tissue
- tissue making up the lymphatic system
- lysosome
- an organelle found in the cytoplasm of most cells (especially in leukocytes and liver and kidney cells)
- macula
- a small yellowish central area of the retina that is rich in cones and that mediates clear detailed vision
- male chest
- the chest of a man
- male internal reproductive organ
- the reproductive organs of a man
- male reproductive gland
- the reproductive organs of a man
- male reproductive system
- the reproductive system of males
- malpighian body
- the capsule that contains Bowman's capsule and a glomerulus at the expanded end of a nephron
- malposed tooth
- a tooth that has grown in a faulty position
- mamilla
- the small projection of a mammary gland
- mamma
- milk-secreting organ of female mammals
- mandibular gland
- a salivary gland inside the lower jaw on either side that produces most of the nocturnal saliva; discharges saliva into the mouth under the tongue
- manubrium
- the upper part of the breastbone
- marrowbone
- a bone containing edible marrow; used especially in flavoring soup
- marsupium
- an external abdominal pouch in most marsupials where newborn offspring are suckled
- masseter
- a large muscle that raises the lower jaw and is used in chewing
- mastoid
- process of the temporal bone behind the ear at the base of the skull
- mastoidale
- the craniometric point at the lowest point of the mastoid process
- matrix
- the formative tissue at the base of a nail
- maxilla
- the jaw in vertebrates that is fused to the cranium
- maxillary sinus
- one of a pair of sinuses forming a cavity in the maxilla
- maxillary vein
- posterior continuation of the pterygoid plexus; joins the superficial temporal vein to form the retromandibular vein
- meatus
- a natural body passageway
- medial condyle
- a condyle on the inner side of the lower extremity of the femur
- medial rectus
- the ocular muscle whose contraction turns the eyeball medially
- mediastinum
- the part of the thoracic cavity between the lungs that contains the heart and aorta and esophagus and trachea and thymus
- medulla
- the inner part of an organ or structure in plant or animal
- medulla spinalis
- a major part of the central nervous system which conducts sensory and motor nerve impulses to and from the brain; a long tubelike structure extending from the base of the brain through the vertebral canal to the upper lumbar region
- megacolon
- an abnormal enlargement of the colon; can be congenital (as in Hirschsprung's disease) or acquired (as when children refuse to defecate)
- Meibomian gland
- a long sebaceous gland that lubricates the eyelids
- member
- the male sex organ (`member' is a euphemism)
- membrane bone
- any bone that develops within membranous tissue without previous cartilage formation; e.g. the clavicle and bones of the skull
- membrane
- a pliable sheet of tissue that covers or lines or connects the organs or cells of animals or plants
- membranous labyrinth
- the sensory structures of the inner ear including the labyrinthine receptors and the cochlea; contained within the bony labyrinth
- meningeal veins
- veins at accompany the meningeal arteries
- meninges
- a membrane (one of 3) that envelops the brain and spinal cord
- meniscus
- (anatomy) a disk of cartilage that serves as a cushion between the ends of bones that meet at a joint
- mentum
- a projection below the mouth of certain mollusks that resembles a chin
- mesencephalon
- the middle portion of the brain
- mesenchyme
- mesodermal tissue that forms connective tissue and blood and smooth muscles
- mesenteric plexus
- a plexus of autonomic nerves
- mesenteric vein
- a tributary of the portal vein passing from the intestine between the two layers of mesentery
- mesentery
- a double layer of peritoneum that attaches to the back wall of the abdominal cavity and supports the small intestines
- mesoblast
- the middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue
- mesocolon
- mesentery that holds the lower colon to the dorsal abdominal wall
- mesothelium
- epithelium originating in the embryonic mesoderm; lines the primordial body cavity
- metacarpal vein
- dorsal and palmar veins of the hand
- metacarpal
- any bone of the hand between the wrist and fingers
- metacarpus
- the part of the hand between the carpus and phalanges
- metaphysis
- the growing part of a long bone between the diaphysis and the epiphysis
- metatarsal
- any bone of the foot between the ankle and the toes
- metatarsal arch
- the short lateral arch formed by the heads of the metatarsals
- metatarsal vein
- dorsal and plantar branches of veins serving the metatarsal region of the foot
- metatarsus
- the skeleton of the human foot between the toes and the tarsus; the corresponding part of the foot in birds or of the hind foot in quadrupeds
- metencephalon
- the part of the hindbrain that develops into the pons and the cerebellum
- metopion
- the craniometric point midway between the frontal eminences of the skull
- microglia
- neuroglial tissue of mesodermal origin that can become phagocytic
- micropenis
- an abnormally small penis
- microtubule
- a microscopically small tubule
- mid-calf
- the middle of the calf; half way between the knee and ankle
- middle cerebral artery
- one of two branches of the internal carotid artery; divides into three branches
- middle cerebral vein
- either of two cerebral veins
- middle ear
- the main cavity of the ear; between the eardrum and the inner ear
- middle finger
- the second finger; between the index finger and the ring finger
- middle meningeal artery
- branch of the maxillary artery; its branches supply meninges
- middle temporal vein
- arises near the eye; joins the superficial temporal veins to form the retromandibular vein
- middle thyroid vein
- a vein on each side that drains the lateral part of the thyroid and empties into the internal jugular vein
- middle
- the middle area of the human torso (usually in front)
- minge
- vulgar term for a woman's pubic hair or genitals
- minimus
- the fifth digit; the little finger or little toe
- modiolus
- the central conical bony pillar of the cochlea
- mons
- a mound of fatty tissue covering the pubic area in women
- Montgomery's tubercle
- one of the sebaceous glands on the areolae of the breast that lubricate the breast during breast-feeding
- mouth
- the externally visible part of the oral cavity on the face and the system of organs surrounding the opening
- mouth
- the opening through which food is taken in and vocalizations emerge
- mouthpart
- any part of the mouth of an insect or other arthropod especially one adapted to a specific way of feeding
- MPS
- a widely distributed system of free and fixed macrophages derived from bone marrow
- mucosa
- mucus-secreting membrane lining all body cavities or passages that communicate with the exterior
- muscle system
- the muscular system of an organism
- muscle
- animal tissue consisting predominantly of contractile cells
- muscle
- one of the contractile organs of the body
- musculophrenic vein
- veins that drain the upper abdominal wall and the lower intercostal spaces and the abdomen
- musculoskeletal system
- the system of muscles and tendons and ligaments and bones and joints and associated tissues that move the body and maintain its form
- musculospiral nerve
- largest branch of the brachial plexus; extends down the humerus to the lateral epicondyle where it divides into one branch that goes to the skin on the back of the hand and another that goes to the underlying extensor muscles
- musculus abductor digiti minimi manus
- the abductor muscle of the little finger
- musculus abductor digiti minimi pedis
- the abductor muscles of the little toe
- musculus abductor hallucis
- the abductor muscle of the great toe
- musculus abductor pollicis
- the abductor muscle of the thumb
- musculus adductor brevis
- the short adductor muscle of the thigh
- musculus adductor hallucis
- the adductor muscle of the great toe
- musculus adductor longus
- the long adductor muscle of the thigh
- musculus articularis cubiti
- a small branch of the triceps that inserts into the capsule of the elbow joint
- musculus articularis genus
- the articular muscle of the knee
- musculus pectoralis minor
- a skeletal muscle that draws down the scapula or raises the ribs
- musculus pectoralis
- either of two large muscles of the chest
- musculus quadriceps femoris
- a muscle of the thigh that extends the leg
- musculus sartorius
- a muscle in the thigh that helps to rotate the leg into the sitting position assumed by a tailor; the longest muscle in the human body
- musculus scalenus
- any of four pairs of muscles extending from the cervical vertebrae to the second rib; involved in moving the neck and in breathing
- musculus serratus posterior
- skeletal muscle that draws the rib cage backward and downward
- musculus sphincter ani externus
- an external ring of striated muscle surrounding the anus
- musculus sphincter ani internus
- an internal ring of smooth muscle formed by circular fibers of the rectum
- musculus sphincter ductus choledochi
- the smooth muscle sphincter of the common bile duct
- musculus sphincter ductus pancreatici
- the smooth muscle sphincter of the main pancreatic duct
- musculus sphincter pupillae
- a ring of smooth muscle surrounding the iris
- musculus sphincter pylori
- the sphincter muscle of the pylorus that separates the stomach from the duodenum
- musculus sphincter urethrae
- a striated sphincter muscle that constricts the urethra
- musculus sternocleidomastoideus
- one of two thick muscles running from the sternum and clavicle to the mastoid and occipital bone; turns head obliquely to the opposite side; when acting together they flex the neck and extend the head
- musculus temporalis
- muscle extending from the temporal fossa to the coronoid process of the mandible; acts to raise the mandible and close the jaws
- musculus teres major
- teres muscle that moves the arm and rotates it medially
- musculus teres minor
- teres muscle that adducts the arm and rotates it laterally
- musculus tibialis
- either of two skeletal muscle in each leg arising from the tibia; provides for movement of the foot
- musculus transversalis abdominis
- a flat muscle with transverse fibers that forms the anterior and lateral walls of the abdominal cavity
- musculus triceps brachii
- the skeletal muscle having three origins that extends the forearm when it contracts
- muzzle
- forward projecting part of the head of certain animals; includes the jaws and nose
- myelencephalon
- the posterior part of the hindbrain in developing vertebrates; forms the medulla oblongata in adults
- myenteric plexus
- a plexus of unmyelinated fibers and postganglionic autonomic cell bodies in the muscular coat of the esophagus and stomach and intestines
- myocardium
- the middle muscular layer of the heart wall
- myometrium
- the smooth muscle forming the wall of the uterus
- nabothian gland
- one of many small glands of the uterine cervix that secrete mucus
- nail
- horny plate covering and protecting part of the dorsal surface of the digits
- naked eye
- the eye unaided by any optical instrument that alters the power of vision or alters the apparent size or distance of objects
- naris
- any of the openings to the nasal cavities that allow air to flow through the cavities to the pharynx
- nasal cavity
- either of the two cavities lying between the floor of the cranium and the roof of the mouth and extending from the face to the pharynx
- nasal concha
- one of several turbinate bones in the nasal cavity
- nasal meatus
- the passages in the nasal cavity formed by the projections of the nasal conchae
- nasal septum
- a partition of bone and cartilage between the nasal cavities
- nasal sinus
- any of the paired sinuses in the bones of the face adjacent to the nasal cavity that are lined with mucous membrane that is continuous with the lining of the nasal cavities
- nasal
- an elongated rectangular bone that forms the bridge of the nose
- nasion
- the craniometric point at the bridge of the nose where the frontal and nasal bones of the skull meet
- nasofrontal vein
- a vein located in the anterior medial part of the orbit; connects the superior ophthalmic with the angular vein
- nasolacrimal duct
- a duct that carries tears from the lacrimal sac to the nasal cavity
- nasopharynx
- cavity forming the upper part of the pharynx
- navicular
- the largest wrist bone on the thumb side
- neb
- a long projecting or anterior elongation of an animal's head; especially the nose
- neencephalon
- the part of the brain having the most recent phylogenetic origin; the cerebral cortex and related parts
- neocortex
- the cortical part of the neencephalon
- nephron
- any of the small tubules that are the excretory units of the vertebrate kidney
- nerve pathway
- a bundle of myelinated nerve fibers following a path through the brain
- nerve plexus
- a network of intersecting nerves
- nerve tissue
- tissue composed of neurons
- nerve
- any bundle of nerve fibers running to various organs and tissues of the body
- nervous system
- the sensory and control apparatus consisting of a network of nerve cells
- nervure
- one of the horny ribs that stiffen and support the wing of an insect
- nervus ischiadicus
- arises from the sacral plexus and passes about halfway down the thigh where it divides into the common peroneal and tibial nerves
- nervus oculomotorius
- supplies extrinsic muscles of the eye
- nervus opticus
- the cranial nerve that serves the retina
- nervus phrenicus
- one of a pair of nerves that arises from cervical spinal roots and passes down the thorax to innervate the diaphragm and control breathing
- nervus saphenus
- a branch of the femoral nerve that supplies cutaneous branches to the inner aspect of the leg and foot
- nervus spinalis
- any of the 31 pairs of nerves emerging from each side of the spinal cord (each attached to the cord by two roots: ventral and dorsal)
- nervus vagus
- a mixed nerve that supplies the pharynx and larynx and lungs and heart and esophagus and stomach and most of the abdominal viscera
- neural arch
- a structure arising dorsally from a vertebral centrum and enclosing the spinal cord
- neural structure
- a structure that is part of the nervous system
- neural tube
- a tube of ectodermal tissue in the embryo from which the brain and spinal cord develop
- neuroepithelium
- epithelium associated with special sense organs and containing sensory nerve endings
- neurohypophysis
- the posterior lobe of the pituitary body; primarily glandular in nature
- neuropil
- the complex network of unmyelinated axones, dendrites, and glial branches that form the bulk of the central nervous system's grey matter and in which nerve cell bodies are embedded
- nictitating membrane
- a protective fold of skin in the eyes of reptiles and birds and some mammals
- nodule
- small rounded wartlike protuberance on a plant
- nose
- the organ of smell and entrance to the respiratory tract; the prominent part of the face of man or other mammals
- notochord
- a flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates
- nucleolar organiser
- the particular part of a chromosome that is associated with a nucleolus after nuclear division
- nucleole
- a small round body of protein in a cell nucleus; such organelles contain RNA and are involved in protein synthesis
- nucleus
- any histologically identifiable mass of neural cell bodies in the brain or spinal cord
- obelion
- the craniometric point on the sagittal suture near the lamboid suture
- oblique vein of the left atrium
- a tributary of the coronary sinus; on the posterior wall of the left atrium
- obturator vein
- a vein formed by the union of tributaries that drain the hip joints and thigh muscles; empties into the internal iliac vein
- occipital bone
- a saucer-shaped membrane bone that forms the back of the skull
- occipital cortex
- that part of the cerebral cortex in either hemisphere of the brain lying in the back of the head
- occipital gyrus
- any of the convolutions of the outer surface of the occipital lobe of the cerebrum
- occipital vein
- a vein that drains the occipital region
- occipitomastoid suture
- the suture between the occipital and the temporal bones; a continuation of the lamboid suture
- occiput
- back part of the head or skull
- ocellus
- an eye having a single lens
- OD
- the right eye
- odontoid process
- a toothlike process at the back of 2nd vertebra of the neck
- oil gland
- a gland that secretes oil
- olecranon
- process of the ulna that forms the outer bump of the elbow and fits into the fossa of the humerus when the arm is extended
- olfactory brain
- a center in the cerebral hemispheres that governs the sense of smell in lower animals; in humans it seems to mediate complex emotional behavior
- olfactory bulb
- one of two enlargements at the terminus of the olfactory nerve at the base of the brain just above the nasal cavities
- oligodendria
- tissue consisting of glial cells with sheetlike processes that form the myelin sheath of nerve fibers
- omasum
- the third compartment of the stomach of a ruminant
- omentum
- a fold of peritoneum supporting the viscera
- ommatidium
- any of the numerous small cone-shaped eyes that make up the compound eyes of some arthropods
- opening
- an aperture or hole that opens into a bodily cavity
- operculum
- a hard flap serving as a cover for (a) the gill slits in fishes or (b) the opening of the shell in certain gastropods when the body is retracted
- ophryon
- the craniometric point in the midline of the forehead immediately above the orbits
- ophthalmic vein
- either of two veins that serve the eye; empties into the cavernous sinus
- optic radiation
- a nerve pathway from the lateral geniculate body to the visual cortex
- orbital point
- the craniometric point at the lowest point on the lower edge of the orbit
- organ
- a fully differentiated structural and functional unit in an animal that is specialized for some particular function
- organ of Corti
- the hearing organ of the inner ear; contains receptors that respond to sound waves
- organ of hearing
- the part of the ear that is responsible for sensations of sound
- organ of speech
- any of the organs involved in speech production
- oropharynx
- cavity formed by the pharynx at the back of the mouth
- os
- a mouth or mouthlike opening
- OS
- the left eye
- os breve
- a bone that is of approximately equal dimension in all directions
- os palatinum
- either of two irregularly shaped bones that form the back of the hard palate and helps to form the nasal cavity and the floor of the orbits
- os pisiforme
- a small wrist bone that articulates only with the triquetral
- os pubis
- one of the three sections of the hipbone; together these two bones form the front of the pelvis
- os sesamoideum
- any of several small round bones formed in a tendon where it passes over a joint
- os sphenoidale
- butterfly-shaped bone at the base of the skull
- os temporale
- a thick bone forming the side of the human cranium and encasing the inner ear
- os trapezium
- the wrist bone on the thumb side of the hand that articulates with the 1st and 2nd metacarpals
- os trapezoideum
- the wrist bone between the trapezium and the capitate bones
- osmoreceptor
- sensory end organ that responds to changes in osmotic pressure
- osteophyte
- small abnormal bony outgrowth
- ostiole
- a small pore especially one in the reproductive bodies of certain algae and fungi through which spores pass
- otic ganglion
- an autonomic ganglion whose postganglionic fibers are distributed to the parotid gland
- ovarian vein
- one of the veins that drain the ovaries; the right opens into the inferior vena cava; the left opens into the left renal vein
- ovary
- (vertebrates) one of usually two organs that produce ova and secrete estrogen and progesterone
- overlip
- the upper lip
- ovipositor
- egg-laying tubular structure at the end of the abdomen in many female insects and some fishes
- ovotestis
- hermaphroditic gonad that contains both testicular and ovarian tissue
- oxtail
- the skinned tail of cattle; used especially for soups
- pad
- the fleshy cushion-like underside of an animal's foot or of a human's finger
- palaeencephalon
- the more primitive parts of the brain phylogenetically; most structures other than the cerebral cortex
- palatine vein
- a vein that drains the region of the palate and empties into the facial vein
- paleocerebellum
- the anterior lobe of the cerebellum which was one of the earliest parts of the hindbrain to develop in mammals
- palm
- the inner surface of the hand from the wrist to the base of the fingers
- pancreas
- a large elongated exocrine gland located behind the stomach; secretes pancreatic juice and insulin
- pancreatic duct
- a duct connecting the pancreas with the intestine
- pancreatic vein
- veins draining the pancreas and emptying into the superior mesenteric and splenic veins
- papilla
- a small projection of tissue at the base of a hair or tooth or feather
- papilla
- a small nipple-shaped protuberance concerned with taste, touch, or smell
- papilla
- (botany) a tiny outgrowth on the surface of a petal or leaf
- papillary muscle
- any of several muscles associated with the atrioventricular valves
- parafovea
- area of the retina immediately surrounding the fovea
- parapodium
- one of a pair of fleshy appendages of a polychete annelid that functions in locomotion and breathing
- parasympathetic
- originates in the brain stem and lower part of the spinal cord; opposes physiological effects of the sympathetic nervous system: stimulates digestive secretions; slows the heart; constricts the pupils; dilates blood vessels
- parathyroid
- any one of four endocrine glands situated above or within the thyroid gland
- paraumbilical vein
- small veins arising in skin around the navel; terminate as accessory portal veins
- parenchyma
- animal tissue that constitutes the essential part of an organ as contrasted with e.g. connective tissue and blood vessels
- parietal bone
- either of two skull bones between the frontal and occipital bones and forming the top and sides of the cranium
- parietal cortex
- that part of the cerebral cortex in either hemisphere of the brain lying below the crown of the head
- parietal gyrus
- any of the convolutions of the outer surface of the parietal lobe of the cerebrum
- parietal pericardium
- the tough outermost layer of the pericardium that is attached to the diaphragm and the sternum
- parietal pleura
- pleura that lines the inner chest walls and covers the diaphragm
- parieto-occipital fissure
- a sulcus near the posterior end of each hemisphere that separates the parietal lobes and the occipital lobes in both hemispheres
- parietomastoid suture
- the suture between the parietal and the temporal bones
- parotid gland
- a large salivary gland that produces 50% of daytime saliva; in human beings it is located in front of and below each ear
- parotid vein
- parotid branches of the facial vein; they drain part of the parotid gland and empty into the retromandibular vein
- pars anterior
- the anterior part of the anterior pituitary
- pars intermedia
- a thin piece of tissue that has become part of the posterior pituitary
- partition
- (anatomy) a structure that separates areas in an organism
- passage
- a path or channel or duct through or along which something may pass
- patent ductus arteriosus
- a ductus arteriosus that failed to close at birth; may require surgical correction
- paw
- a clawed foot of an animal especially a quadruped
- pectoral arch
- the bony arch formed by the collarbones and shoulder blades in humans
- pectoral fin
- either of a pair of fins situated just behind the head in fishes that help control the direction of movement
- pectoral girdle
- a skeletal support to which the forelimbs of vertebrates are attached
- pectoral vein
- veins that drain the pectoral muscles and empty into the subclavian vein
- pedal extremity
- the extremity of the limb in vertebrates
- peeper
- an informal term referring to the eye
- peg
- informal terms for the leg
- pellicle
- thin protective membrane in some protozoa
- pelvic cavity
- the space bounded by the bones of the pelvis and containing the pelvic viscera
- pelvic fin
- either of a pair of fins attached to the pelvic girdle in fishes that help control the direction of movement; correspond to hind limbs of a land vertebrate
- pelvis
- a structure shaped like a funnel in the outlet of the kidney into which urine is discharged before passing into the ureter
- pennon
- wing of a bird
- perforated eardrum
- an eardrum with a hole or tear in it; can interfere with normal hearing and cause other ear problems
- perforating vein
- veins that accompany the perforating arteries; drain leg muscles; empty into the deep femoral vein
- periarterial plexus
- an autonomic plexus that accompanies an artery
- pericardial cavity
- the space between the layers of the pericardium that contains fluid that lubricates the membrane surfaces and allows easy heart movement
- pericardial sac
- the membrane surrounding the heart
- pericardial vein
- several small veins from the pericardium
- pericardium
- a serous membrane with two layers that surrounds the heart
- perimysium
- the sheath of connective tissue that covers a bundle of muscle fibers
- perineum
- the general region between the anus and the genital organs
- perineurium
- the sheath of connective tissue that covers a bundle of nerve fibers
- periosteum
- a dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles; contains nerves and blood vessels that nourish the enclosed bone
- peripheral nervous system
- the section of the nervous system lying outside the brain and spinal cord
- peristome
- (botany) fringe of toothlike appendages surrounding the mouth of a moss capsule
- peristome
- region around the mouth in various invertebrates
- perithelium
- tissue layer around small blood vessels
- peritoneum
- a transparent membrane that lines the abdominal cavity in mammals and covers most of the viscera
- peroneus
- muscle of the lower leg that is involved in moving the foot
- Peyer's patch
- any of several lymph nodes in the walls of the intestines near the junction of the ileum and colon
- phalanx
- any of the bones of the fingers or toes
- pharyngeal vein
- veins from the pharyngeal plexus that empty into the internal jugular vein
- pharynx
- the passage to the stomach and lungs; in the front part of the neck below the chin and above the collarbone
- phrenic vein
- either of two veins that drain the diaphragm
- physiological sphincter
- a sphincter that is not recognizable at autopsy because its resting arrangement cannot be distinguished from adjacent tissue
- pia mater
- the highly vascular innermost of the 3 meninges
- pilus
- hairlike structure especially on the surface of a cell or microorganism
- pineal eye
- a sensory structure capable of light reception located on the dorsal side of the diencephalon in various reptiles
- pinguecula
- a slightly elevated elastic tissue deposit in the conjunctiva that may extend to the cornea but does not cover it
- piriform area
- pear-shaped neural structure on either side of the brain in the rhinencephalon
- placenta
- the vascular structure in the uterus of most mammals providing oxygen and nutrients for and transferring wastes from the developing fetus
- plastron
- (zoology) the part of a turtle's shell forming its underside
- plate
- any flat platelike body structure or part
- platysma
- either of two broad muscles located on either side of the neck and innervated by the facial nerve; extends from lower jaw to clavicle and is involved in moving the mouth and jaw
- pleopod
- one of the paired abdominal appendages of certain aquatic crustaceans that function primarily for carrying the eggs in females and are usually adapted for swimming
- pleura
- the thin serous membrane around the lungs and inner walls of the chest
- pleural cavity
- the cavity in the thorax that contains the lungs and heart
- plexus dentalis
- a plexus of nerves serving the teeth
- plexus pulmonalis
- one of two autonomic nerve plexuses in each lung
- plexus sacralis
- a nerve plexus formed by the 4th and 5th lumbar and 1st, 2nd, 3rd sacral nerves; supplies the pelvic region and lower limbs
- plexus
- a network of intersecting blood vessels or intersecting nerves or intersecting lymph vessels
- plica vocalis
- either of two pairs of folds of mucous membrane projecting into the larynx
- pock
- a pustule in an eruptive disease
- pocket
- (anatomy) saclike structure in any of various animals (as a marsupial or gopher or pelican)
- podetium
- an organ or body resembling a stalk; especially the outgrowth of the thallus of certain lichens on which the ascocarp is borne
- pogonion
- the craniometric point that is the most forward-projecting point on the anterior surface of the chin
- pollex
- the thick short innermost digit of the forelimb
- pons Varolii
- a band of nerve fibers linking the medulla oblongata and the cerebellum with the midbrain
- popliteal vein
- a vein arising in the knee and ascending to become the femoral vein
- pore
- any small opening in the skin or outer surface of an animal
- porta hepatis
- opening for major blood vessels to enter and leave the liver
- portacaval shunt
- shunt that is created surgically between the portal vein and the inferior vena cava so that blood from the abdominal organs can bypass the liver
- portal system
- system of veins that carry blood from the abdominal organs to the liver
- postcentral gyrus
- the convolution of parietal lobe that is bounded in front by the central sulcus
- posterior cardinal vein
- a major drainage channel from the caudal part of the body
- posterior cerebral artery
- arises from the basilar artery; divides into three branches
- posterior facial vein
- posterior branch of the facial vein; formed by temporal veins in front of the ear
- posterior labial veins
- veins that pass posterior from the labia majora to the internal pudendal vein
- posterior meningeal artery
- branch of the ascending pharyngeal artery that supplies the dura mater of the posterior cranial fossa
- posterior naris
- either one of the two posterior openings at the back of the nasal cavity leading to the nasopharynx
- posterior vein of the left ventricle
- arises near the apex of the heart and empties into the coronary sinus
- precava
- receives blood from the head and arms and chest and empties into the right atrium of the heart; formed from the azygos and both brachiocephalic veins
- precentral gyrus
- the convolution of the frontal lobe that is bounded in back by the central sulcus and that contains the motor area
- precordium
- the external surface of the body overlying the heart and stomach
- preen gland
- oil-secreting gland situated at the base of the tail in most birds
- prefrontal cortex
- the anterior part of the frontal lobe
- prehensor
- the anterior pair of legs of a centipede that are modified to seize prey and inject venom from the toxicognaths
- prepyloric vein
- a tributary of the right gastric vein
- pressure point
- an area on the skin that is highly sensitive to pressure
- pricker
- a small sharp-pointed tip resembling a spike on a stem or leaf
- proboscis
- the human nose (especially when it is large)
- proboscis
- a long flexible snout as of an elephant
- pronator
- a muscle that produces or assists in pronation
- pronucleus
- the nucleus of the ovum or sperm after fertilization but before they fuse to form the nucleus of the zygote
- prostate
- a firm partly muscular chestnut sized gland in males at the neck of the urethra; produces a viscid secretion that is the fluid part of semen
- protective fold
- a flap of tissue that protects what it covers
- prothorax
- the anterior part of an insect's thorax; bears the first pair of legs
- proud flesh
- the swollen tissue around a healing wound or ulcer
- pseudopod
- temporary outgrowth used by some microorganisms as an organ of feeding or locomotion
- psoas
- either of two muscles of the abdomen and pelvis that flex the trunk and rotate the thigh
- pterion
- the craniometric point in the region of the sphenoid fontanelle
- pterygium
- either of two thickened triangular layers of conjunctiva extending from the nasal edge of the eye to the cornea; it arises from irritation of the pinguecula
- pterygoid muscle
- muscle descending from the sphenoid bone to the lower jaw
- pterygoid plexus
- a plexus of veins draining the region of the pterygoid muscles and draining into the internal maxillary and anterior facial veins
- pterygoid process
- two bony processes descending from the body of the sphenoid bone
- pudding face
- a large fat human face
- pudendal cleavage
- the fissure between the labia majora
- pudendal vein
- vein of the pudendum
- pudendum
- human external genital organs collectively especially of a female
- pug nose
- a short nose; flattened and turned up at the end
- pulmonary trunk
- the artery that carries venous blood from the right ventricle of the heart and divides into the right and left pulmonary arteries
- pulmonary valve
- a semilunar valve between the right ventricle and the pulmonary artery; prevents blood from flowing from the artery back into the heart
- pulmonary vein
- any of four veins that carry arterial blood from the lungs to the left atrium of the heart
- pulp
- the soft inner part of a tooth
- pulp cavity
- the central cavity of a tooth containing the pulp (including the root canal)
- puppy fat
- fat on the body of a baby or child; disappears at adolescence
- Purkinje fiber
- a specialized cardiac muscle fiber that is part of the Purkinje network
- Purkinje's system
- a network of Purkinje fibers that carry the cardiac impulse from the atrioventricular node to the ventricles of the heart and causes them to contract
- pustule
- a small inflamed elevation of skin containing pus; a blister filled with pus
- putamen
- the outer reddish part of the lenticular nucleus
- pyloric vein
- receives veins from the upper surfaces of the stomach and empties into the portal vein
- pylorus
- a small circular opening between the stomach and the duodenum
- quick
- any area of the body that is highly sensitive to pain (as the flesh underneath the skin or a fingernail or toenail)
- quill
- a stiff hollow protective spine on a porcupine or hedgehog
- radial vein
- superficial veins ascending the radial side of the forearm; combines with the ulnar veins to form the brachial vein
- radiation
- a radial arrangement of nerve fibers connecting different parts of the brain
- radicle
- (anatomy) a small structure resembling a rootlet (such as a fibril of a nerve)
- radius
- the outer and slightly shorter of the two bones of the human forearm
- ramus
- the posterior part of the mandible that is more or less vertical
- rattle
- loosely connected horny sections at the end of a rattlesnake's tail
- ray
- any of the stiff bony spines in the fin of a fish
- receptor
- a cellular structure that is postulated to exist in order to mediate between a chemical agent that acts on nervous tissue and the physiological response
- receptor
- an organ having nerve endings (in the skin or viscera or eye or ear or nose or mouth) that respond to stimulation
- rectum
- the terminal section of the alimentary canal; from the sigmoid flexure to the anus
- rectus
- any of various straight muscles
- rectus superior
- the ocular muscle whose contraction turns the eyeball upward and medially
- red bone marrow
- bone marrow of children and some adult bones that is required for the formation of red blood cells
- reflex arc
- the neural path of a reflex
- renal cortex
- the cortex of the kidney containing the glomeruli and the convoluted tubules
- renal vein
- veins that accompany renal arteries; open into the vena cava at the level of the 2nd lumbar vertebra
- reproductive organ
- any organ involved in sexual reproduction
- RES
- a widely distributed system consisting of all the cells able to ingest bacteria or colloidal particles etc, except for certain white blood cells
- respiratory center
- the center in the medulla oblongata and pons that integrates sensory information about the level of oxygen and carbon dioxide in the blood and determines the signals to be sent to the respiratory muscles
- respiratory organ
- any organ involved in the process of respiration
- respiratory system
- the system for taking in oxygen and giving off carbon dioxide; in terrestrial animals this is accomplished by breathing
- rete testis
- network of tubules carrying sperm from the seminiferous tubules to the vasa efferentia
- reticulum
- the second compartment of the stomach of a ruminant
- retina
- the innermost light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve
- rhinion
- the anterior tip at the end of the suture of the nasal bones
- rhomboid
- any of several muscles of the upper back that help move the shoulder blade
- rib
- a riblike supporting or strengthening part of an animal or plant
- rib cage
- the bony enclosing wall of the chest
- ribosome
- an organelle in the cytoplasm of a living cell; they attach to mRNA and move down it one codon at a time and then stop until tRNA brings the required amino acid; when it reaches a stop codon it falls apart and releases the completed protein molecule for use by the cell
- ridge
- any long raised border or margin of a bone or tooth or membrane
- right atrioventricular valve
- valve with three cusps; situated between the right atrium and the right ventricle; allows blood to pass from atrium to ventricle and closes to prevent backflow when the ventricle contracts
- right brain
- the cerebral hemisphere to the right of the corpus callosum that controls the left half of the body
- right coronary artery
- arises from the right aortic sinus; supplies the right side of the heart
- right ventricle
- the chamber on the right side of the heart that receives venous blood from the right atrium and pumps it into the pulmonary trunk
- right
- the hand that is on the right side of the body
- rima
- a narrow elongated opening or fissure between two symmetrical parts
- Rolando's area
- the cortical area that influences motor movements
- Roman nose
- a nose with a prominent slightly aquiline bridge
- root
- the embedded part of a bodily structure such as a tooth, nail, or hair
- root canal
- the passage in the root of a tooth through which its nerve and blood vessels enter the pulp cavity
- rostrum
- beaklike projection of the anterior part of the head of certain insects such as e.g. weevils
- rotator cuff
- a supporting structure of the shoulder consisting of the muscles and tendons that attach the arm to the shoulder joint and enable the arm to move
- round bone
- bones that are round in shape
- rudiment
- the remains of a body part that was functional at an earlier stage of life
- ruga
- (anatomy) a fold or wrinkle or crease
- SA node
- a specialized bit of heart tissue that controls the heartbeat
- sac
- a structure resembling a bag in an animal
- saccule
- a small sac or pouch (especially the smaller chamber of the membranous labyrinth)
- sacral nerve
- any of five pairs of spinal nerves emerging from the sacral region of the spinal cord
- sacral vein
- vein of the sacral region
- sacral vertebra
- one of 5 vertebrae in the human spine that fuse in the adult to form the sacrum
- sacrum
- wedge-shaped bone consisting of five fused vertebrae forming the posterior part of the pelvis; its base connects with the lowest lumbar vertebra and its tip with the coccyx
- saddle
- posterior part of the back of a domestic fowl
- salivary duct
- a duct through which saliva passes from the salivary gland into the mouth
- salivary gland
- any of three pairs of glands in the mouth and digestive system that secrete saliva for digestion
- salpinx
- a tube in the uterus or the ear
- saphenous vein
- either of two chief superficial veins of the leg that drain blood from the foot
- sarcolemma
- an extensible membrane enclosing the contractile substance of a muscle fiber
- sarcosome
- a large mitochondrion in a striated muscle fiber
- scalp
- the skin that covers the top of the head
- scapula
- either of two flat triangular bones one on each side of the shoulder in human beings
- scar tissue
- the connective tissue that forms a scar; consists of fibroblasts in new scars and collagen fibers in old scars
- sclera
- the whitish fibrous membrane (albuginea) that with the cornea forms the outer covering and protection of the eyeball
- scleral veins
- tributaries of the anterior ciliary veins that drain the sclera of the eye
- scrotal vein
- veins passing from the scrotum to the pudendal veins
- scrotum
- the external pouch that contains the testes
- scut
- a short erect tail
- semicircular canal
- one of three tube loops filled with fluid and in planes nearly at right angles with one another; concerned with equilibrium
- semilunar valve
- a heart valve with cusps shaped like half-moons; prevents blood from flowing back into the heart
- seminal duct
- the efferent duct of the testis in man
- seminal vesicle
- either of a pair of glands located on either side of the male urinary bladder that open into the vas deferens and that secrete many components of semen during ejaculation
- seminiferous tubule
- any of the numerous long convoluted tubules in the testis which are the sites where spermatozoa mature
- semipermeable membrane
- a membrane (as a cell membrane) that allows some molecules to pass through but not others
- sensorimotor area
- an area of the cortex including the precentral gyrus and the postcentral gyrus and combining sensory and motor functions
- sensorium
- the areas of the brain that process and register incoming sensory information and make possible the conscious awareness of the world
- sensory hair
- a long stiff hair growing from the snout or brow of most mammals as e.g. a cat
- sensory system
- the body's system of sense organs
- septum
- (anatomy) a dividing partition between two tissues or cavities
- sericterium
- silk-producing gland of insects (especially of a silkworm) or spiders
- serosa
- a thin membrane lining the closed cavities of the body; has two layers with a space between that is filled with serous fluid
- serratus posterior inferior
- a thin quadrilateral muscle at the junction of the thoracic and lumbar regions; acts to counteract the pull of the diaphragm on the ribs to which it is attached
- serratus posterior superior
- a thin quadrilateral muscle of the upper and dorsal part of the thorax; acts to elevate the upper ribs
- serratus
- any of several muscles of the trunk
- seta
- stalk of a moss capsule
- seta
- a stiff hair or bristle
- shank
- the part of the human leg between the knee and the ankle
- shank's mare
- you own legs
- shin
- the front part of the human leg between the knee and the ankle
- shin
- the inner and thicker of the two bones of the human leg between the knee and ankle
- short saphenous vein
- a vein running from the foot up the back of the leg to the knee
- shoulder
- the part of the body between the neck and the upper arm
- shunt
- a passage by which a bodily fluid (especially blood) is diverted from one channel to another
- side
- either the left or right half of a body
- sigmoid colon
- the s-shaped curve between the descending colon and the rectum
- sigmoid sinus
- an S-shaped dural sinus on the temporal and occipital bones
- sigmoid vein
- tributaries of the inferior mesenteric vein; drains the sigmoid colon
- sinciput
- the front part of the head or skull (including the forehead)
- sinew
- a cord or band of inelastic tissue connecting a muscle with its bony attachment
- sinus
- any of various air-filled cavities especially in the bones of the skull
- sinus rectus
- an unpaired sinus of the dura mater
- sinus transversus
- a paired dural sinus; terminates in the sigmoid sinus
- sinus
- a wide channel containing blood; does not have the coating of an ordinary blood vessel
- sinusoid
- tiny endothelium-lined passages for blood in the tissue of an organ
- siphon
- a tubular organ in an aquatic animal (especially in mollusks) through which water can be taken in or expelled
- skeletal muscle
- a muscle that is connected at either or both ends to a bone and so move parts of the skeleton; a muscle that is characterized by transverse stripes
- skeletal structure
- any structure created by the skeleton of an organism
- skin graft
- a piece of skin taken from a donor area and surgically grafted at the site of an injury or burn
- skull
- the bony skeleton of the head of vertebrates
- small
- the slender part of the back
- small intestine
- the longest part of the alimentary canal; where digestion is completed
- smooth muscle
- muscle tissue that does not appear striated under the microscope; has the form of thin layers or sheets
- socket
- a bony hollow into which a structure fits
- soft palate
- a muscular flap that closes off the nasopharynx during swallowing or speaking
- sole
- the underside of the foot
- soleus
- a broad flat muscle in the calf of the leg under the gastrocnemius muscle
- spermatic cord
- a structure resembling a cord that suspends the testis within the scrotum and contains the vas deferens and other vessels and nerves
- sphenion
- the anterior tip of the parietal bone
- sphenoid fontanel
- the irregularly shaped area on either side of the cranium where the frontal bone and the anterior tip of the parietal bone and the temporal bone and the greater wing of the sphenoid bone meet; corresponds to the pterion when bones have ossified
- spicule
- small pointed structure serving as a skeletal element in various marine and freshwater invertebrates e.g. sponges and corals
- spinal nerve root
- one of two roots of the spinal nerves
- spinal nerve roots
- either of two roots of the spinal nerves
- spinal vein
- veins that drain the spinal cord
- spindlelegs
- long thin legs
- spine
- a sharp rigid animal process or appendage; as a porcupine quill or a ridge on a bone or a ray of a fish fin
- spiracle
- a breathing orifice
- splanchnic nerve
- any of several nerves of the sympathetic part of the autonomic nervous system that innervate viscera and blood vessels
- splenic vein
- a vein formed by several small veins on the surface of the spleen; joins the superior mesenteric to form the portal vein
- splenius
- either of two flat muscles that extend from the upper vertebrae to the base of the skull and serve to rotate or flex or extend the head and neck
- splint bone
- a rudimentary metacarpal or metatarsal bone on either side of the cannon bone in the leg of a horse or related animal
- spur
- tubular extension at the base of the corolla in some flowers
- stapes
- the stirrup-shaped ossicle that transmits sound from the incus to the cochlea
- stellate venule
- a star-shaped group of venules in the renal cortex
- stephanion
- the craniometric point on the coronal suture above the acoustic meatus
- sternocleidomastoid vein
- drains the sternocleidomastoid muscle; empties into the internal jugular vein
- stigma
- an external tracheal aperture in a terrestrial arthropod
- stinger
- a sharp organ of offense or defense (as of a wasp or stingray or scorpion) often connected with a poison gland
- stinging hair
- a multicellular hair in plants like the stinging nettle that expels an irritating fluid
- stoma
- a mouth or mouthlike opening (especially one created by surgery on the surface of the body to create an opening to an internal organ)
- stretch receptor
- a receptor in a muscle that responds to stretching of the muscle tissue
- striated muscle tissue
- muscle tissue characterized by transverse stripes
- stroma
- the supporting tissue of an organ (as opposed to parenchyma)
- stump
- the part of a limb or tooth that remains after the rest is removed
- style
- a slender bristlelike or tubular process
- stylet
- small needlelike appendage; especially the feeding organ of a tardigrade
- styloid process
- extends from the base of the temporal bone
- stylomastoid vein
- a vein that drains the tympanic cavity and empties into the retromandibular vein
- subclavian vein
- a continuation of the axillary vein; joins the internal jugular to form the brachiocephalic vein
- sublingual gland
- a small salivary gland that produces mucin (the viscous component of saliva); in human beings it is located on either side of the mouth under the tongue
- sublingual vein
- a tributary of the lingual vein
- submucosa
- the connective tissue beneath mucous membrane
- substantia alba
- whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths
- subthalamic nucleus
- an oval mass of grey matter located in the caudal part of the subthalamus; associated with the striate body
- subthalamus
- the ventral part of the thalamus
- sucker
- an organ specialized for sucking nourishment or for adhering to objects by suction
- sudoriferous gland
- any of the glands in the skin that secrete perspiration
- sulcus
- (anatomy) any of the narrow grooves in an organ or tissue especially those that mark the convolutions on the surface of the brain
- superciliary arch
- a ridge on the frontal bone above the eye socket
- superficial epigastric vein
- empties into the great saphenous vein
- superficial middle cerebral vein
- a large vein along the line of the Sylvian fissure to the cavernous sinus
- superficial temporal vein
- join the middle temporal vein to empty into the retromandibular vein
- superior cerebellar artery
- the superior branch of the cerebellar artery
- superior cerebral vein
- a cerebral vein that drains the dorsal convexity of the cerebral hemisphere and empties into the cavernous sinus
- superior colliculus
- an essential visual center between the retina and the striate cortex
- superior epigastric veins
- veins that accompany the superior epigastric artery
- superior labial vein
- a tributary of the facial vein that drains the upper lip
- superior mesenteric artery
- originates from the upper part of the aorta that supplies the small intestines and the cecum and the colon
- superior ophthalmic vein
- a vein that begins at the inner angle of the eye socket and passes through the superior orbital fissure to empty into the cavernous sinus
- superior pulmonary vein
- either of two pulmonary veins (left and right) returning blood from the superior lobes of the lungs
- superior thalamostriate vein
- a long vein that helps to form the internal cerebral vein
- superior thyroid vein
- a vein on each side that drains the upper part of the thyroid and empties into the internal jugular vein
- supinator
- a muscle (especially in the forearm) that produces or assists in supination
- supraorbital vein
- drains the front of the scalp; unites with the supratrochlear vein to form the angular vein
- supratrochlear vein
- drains the front of the scalp; unites with the supraorbital vein to form the angular vein
- sweat duct
- a small duct that conveys sweat from a sudoriferous gland to the surface of the skin
- Sylvian aqueduct
- a canal connecting the third and fourth ventricles
- sympathetic nervous system
- originates in the thoracic regions of the spinal cord; opposes physiological effects of the parasympathetic: reduces digestive secretions; speeds the heart; contracts blood vessels
- symphysion
- the most forward point of the alveolar process of the mandible
- synovial membrane
- a thin membrane in synovial (freely moving) joints that lines the joint capsule and secretes synovial fluid
- syrinx
- the vocal organ of a bird
- system
- a group of physiologically or anatomically related organs or parts
- tail
- the posterior part of the body of a vertebrate especially when elongated and extending beyond the trunk or main part of the body
- talon
- a sharp hooked claw especially on a bird of prey
- taret organ
- (endocrinology) organ most affected by a particular hormone
- target organ
- (radiology) organ intended to receive the therapeutic dose of a radioactive substance
- tarsal
- any bone of the tarsus
- tarsus
- the part of the foot of a vertebrate between the metatarsus and the leg; in human beings the bones of the ankle and heel collectively
- telencephalon
- the anterior division of the forebrain; the cerebrum and related parts of the hypothalamus
- temple
- the flat area on either side of the forehead
- temporal artery
- any of the three arteries on either side of the brain supplying the cortex of the temporal lobe
- temporal cortex
- that part of the cerebral cortex in either hemisphere of the brain lying inside the temples of the head
- temporal gyrus
- any of the convolutions of the outer surface of the temporal lobe of the cerebrum
- temporal vein
- any of several veins draining the temporal region
- tendon of Achilles
- a large tendon that runs from the heel to the calf
- tensor
- any of several muscles that cause an attached structure to become tense or firm
- tensor tympani
- a small muscle in the middle ear that tenses to protect the eardrum
- tentacle
- any of various elongated tactile or prehensile flexible organs that occur on the head or near the mouth in many animals; used for feeling or grasping or locomotion
- tentorium
- (anatomy) a fold of dura mater that covers the cerebellum and supports the occipital lobes of the cerebrum
- teres
- either of two muscles in the shoulder region that move the shoulders and arms
- testicular vein
- a vein from the testicles
- thalamostriate vein
- a vein serving the thalamus and corpus striatum
- thalamus
- large egg-shaped structures of grey matter that form the dorsal subdivision of the diencephalon
- thenar
- the fleshy area of the palm at the base of the thumb
- thermoreceptor
- a sensory receptor that responds to heat and cold
- thick skin
- skin that is very thick (as an elephant or rhinoceros)
- thigh
- the part of the leg between the hip and the knee
- third ventricle
- a narrow ventricle in the midplane below the corpus callosum; communicates with the fourth ventricle via the Sylvian aqueduct
- thoracic aorta
- a branch of the descending aorta; divides into the iliac arteries
- thoracic duct
- the major duct of the lymphatic system
- thoracic nerve
- any of twelve pairs of spinal nerves emerging from the thoracic region of the spinal cord
- thoracic vein
- veins that drain the thoracic walls
- thoracoepigastric vein
- a vein arising from the region of the superficial epigastric vein and opening into the axillary vein or thoracic vein
- thorax
- part of an insect's body that bears the wings and legs
- thorax
- the middle region of the body of an arthropod between the head and the abdomen
- throat
- the part of an animal's body that corresponds to a person's throat
- thumbnail
- the nail of the thumb
- thymus
- a ductless glandular organ at the base of the neck that produces lymphocytes and aids in producing immunity; atrophies with age
- thyroid vein
- any of several small veins draining blood from the thyroid area
- thyroid
- located near the base of the neck
- tibial vein
- veins of the lower leg; empty into the popliteal vein
- tibialis anterior
- a muscle running from the tibia to the first metatarsal and cuneiform bones
- tibialis posterior
- a deep muscle of the leg
- tissue
- part of an organism consisting of an aggregate of cells having a similar structure and function
- toe
- one of the digits of the foot
- toe
- forepart of a hoof
- toenail
- the nail at the end of a toe
- tomentum
- a network of tiny blood vessels between the cerebral surface of the pia mater and the cerebral cortex
- tooth
- hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defense
- tooth
- toothlike structure in invertebrates found in the mouth or alimentary canal or on a shell
- topknot
- showy crest or knot of hair or feathers
- toxicognath
- either of a pair of poison fangs in the modified front pair of legs of the centipede
- trabecula
- rod-shaped structures of fibrous tissue that divide an organ into parts (as in the penis) or stabilize the structure of an organ (as in the spleen)
- trachea
- one of the tubules forming the respiratory system of most insects and many arachnids
- trachea
- membranous tube with cartilaginous rings that conveys inhaled air from the larynx to the bronchi
- tracheal vein
- several small veins from the trachea
- tract
- a system of body parts that together serve some particular purpose
- tragus
- a small cartilaginous flap in front of the external opening of the ear
- transverse colon
- the part of the large intestine that extends across the abdominal cavity and joins the ascending to the descending colon
- transverse process
- one of two processes that extend from each vertebra and provide the point of articulation for the ribs
- triceps
- any skeletal muscle having three origins (but especially the triceps brachii)
- trochanter
- one of the bony prominences developed near the upper extremity of the femur to which muscles are attached
- trophoblast
- the membrane that forms the wall of the blastocyst in early development; aids implantation in the uterine wall
- trotter
- foot of a pig or sheep especially one used as food
- true rib
- one of the first seven ribs in a human being which attach to the sternum
- tube foot
- tentacular tubular process of most echinoderms (starfish and sea urchins and holothurians) having a sucker at the end and used for e.g. locomotion and respiration
- tube
- (anatomy) any hollow cylindrical body structure
- tubular cavity
- a cavity having the shape of a tube
- tubule
- a small tube
- tuft
- a bunch of feathers or hair
- tunica albuginea testes
- whitish cover of the testicle
- turbinal
- any of the scrolled spongy bones of the nasal passages in man and other vertebrates
- tusk
- a long pointed tooth specialized for fighting or digging; especially in an elephant or walrus or hog
- tympanic bone
- the bone enclosing the middle ear
- tympanic vein
- veins from the tympanic cavity that empty into the retromandibular vein
- ulnar vein
- any of several veins of the forearm
- umbilical vein
- a vein in the umbilical cord; returns nutrient blood from the placenta to the fetus
- umbilical vesicle
- membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functional
- umbilical
- membranous duct connecting the fetus with the placenta
- underbelly
- the soft belly or underside of an animal's body
- underlip
- the lower lip
- underpart
- a part lying on the lower side or underneath an animal's body
- undescended testicle
- a testis that fails to move into the scrotum as the male fetus develops
- upper respiratory tract
- the nose and throat and trachea
- ureter
- either of a pair of thick-walled tubes that carry urine from the kidney to the urinary bladder
- urethra
- duct through which urine is discharged in most mammals and which serves as the male genital duct
- urinary bladder
- a membranous sac for temporary retention of urine
- urinary tract
- the organs and tubes involved in the production and excretion of urine
- urochord
- a notochord of a larval tunicate typically confined to the caudal region
- uropygium
- posterior part of a bird's body from which the tail feathers grow
- uterine cavity
- the space inside the uterus between the cervical canal and the Fallopian tubes
- uterine vein
- one of two veins on each side that arise from the uterine plexus and empty into the internal iliac vein
- uterus
- a hollow muscular organ in the pelvic cavity of females; contains the developing fetus
- utricle
- a small pouch into which the semicircular canals open
- uvea
- the part of the eye that contains the iris and ciliary body and choroid
- uveoscleral pathway
- a tubule that drains excess aqueous humor
- uvula
- a small pendant fleshy lobe at the back of the soft palate
- vacuole
- a tiny cavity filled with fluid in the cytoplasm of a cell
- vagina
- the lower part of the female reproductive tract; a moist canal in female mammals extending from the labia minora to the uterus
- valve
- a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it
- valvelet
- a small valve
- vane
- the flattened weblike part of a feather consisting of a series of barbs on either side of the shaft
- varicose vein
- a vein that is permanently dilated; most common in the legs
- vas
- a tube in which a body fluid circulates
- vasa efferentia
- the several highly convoluted tubules that lead from the rete testis to the vas deferens and form the head of the epididymis
- vasa vasorum
- any small blood vessel ramifying on the outside of a major artery or vein
- vascular structure
- a structure composed of or provided with blood vessels
- vascular system
- the vessels and tissue that carry or circulate fluids such as blood or lymph or sap through the body of an animal or plant
- vegetation
- an abnormal growth or excrescence (especially a warty excrescence on the valves of the heart)
- vein of penis
- a vein serving the penis
- vein
- a blood vessel that carries blood from the capillaries toward the heart
- vena bulbi penis
- vein of the head of the penis; tributary of the internal pudendal vein that drains the perineum
- vena bulbi vestibuli
- vein of the vestibular bulb
- vena canaliculi cochleae
- vein of the cochlear canal
- vena cava
- either of two large veins that return oxygen-depleted blood to the right atrium of the heart
- vena dorsalis clitoridis profunda
- deep dorsal vein of the clitoris; tributary of the vesical venous plexus
- vena profunda penis
- deep vein of the penis; enters the prostatic plexus
- vena vertebralis
- a vein that goes through the foramina of the cervical vertebrae and forms a plexus around the vertebral artery; empties into the brachiocephalic vein
- vena vesicalis
- veins that drain the vesical plexus and join the internal iliac veins
- vena vestibularis
- veins that drain the saccule and utricle
- vena vorticosum
- a vein formed by branches from the back surface of the eye and the ciliary body; empties into the ophthalmic veins
- venae dorsales clitoridis superficiales
- superficial dorsal veins of the clitoris; tributaries of the external pudendal vein on either side
- venae dorsales penis profunda
- deep dorsal vein of the penis; tributary of the prostatic plexus
- venae dorsales penis superficiales
- superficial dorsal veins of the penis; paired tributaries of the external pudendal veins on each side
- venae interlobulares hepatis
- interlobular veins of the liver
- venae interlobulares renis
- interlobular veins of the kidney; receive blood from the arcuate vein and empty into the renal veins
- venae palpebrales
- veins of the eyelids
- venae profundae clitoridis
- deep veins of the clitoris; join the vesical plexus
- venae renis
- veins of the kidney; drain the kidney into the renal vein
- venation
- (zoology) the system of venous blood vessels in an animal
- vent
- external opening of urinary or genital system of a lower vertebrate
- venter
- a bulging body part (as the belly of a muscle)
- venter
- the womb
- ventricle
- one of four connected cavities in the brain; is continuous with the central canal of the spinal cord and contains cerebrospinal fluid
- vermis
- the narrow central part of the cerebellum between the two hemispheres
- vertebra
- one of the bony segments of the spinal column
- vestibular apparatus
- organs mediating the labyrinthine sense; concerned with equilibrium
- vestibular gland
- a gland that opens into the vestibule of the vagina; secretions lubricate the vagina during coitus
- vestibule
- any of various bodily cavities leading to another cavity (as of the ear or vagina)
- vestibule of the ear
- the central cavity of the bony labyrinth of the ear
- vestibule of the vagina
- the space between the labia minora containing the orifice of the urethra
- villus
- a minute hairlike projection on mucous membrane
- visceral pleura
- pleura that covers the lungs
- visual area
- the cortical area that receives information from the lateral geniculate body of the thalamus
- visual system
- the sensory system for vision
- vital organ
- a bodily organ that is essential for life
- voluntary muscle
- striated muscle that can be controlled voluntarily
- vomer
- thin trapezoidal bone of the skull forming the posterior and inferior parts of the nasal septum
- vulva
- external parts of the female genitalia
- waist
- the narrowing of the body between the ribs and hips
- wasp waist
- a very slender waist
- water blister
- blister containing a nonpurulent clear watery content
- water vascular system
- system of fluid-filled tubes used by echinoderms in locomotion and feeding and respiration
- web
- membrane connecting the toes of some aquatic birds and mammals
- webbed foot
- a bird's foot with folds of skin between the toes
- webfoot
- a foot having the toes connected by folds of skin
- Wernicke's center
- the auditory word center; located in the posterior part of the superior temporal convolution in most people
- wing
- a movable organ for flying (one of a pair)
- wisdom tooth
- any of the last 4 teeth on each side of the upper and lower jaw; the last of the permanent teeth to erupt (between ages 16 and 21)
- wishbone
- the furcula of a domestic fowl
- withers
- the highest part of the back at the base of the neck of various animals especially draft animals
- Wormian bone
- any of the tiny soft bones found in the sutures between cranial bones
- xiphoid process
- smallest of the three parts of the breastbone; articulates with the corpus sternum and the seventh rib
- yellow bone marrow
- bone marrow that is yellow with fat; found at the ends of long bones in adults
- yolk sac
- membranous structure enclosing the yolk of eggs in birds, reptiles, marsupials, and some fishes; circulates nutrients to the developing embryo
- zona pellucida
- thick membrane around the mammalian ovum; can be penetrated by one sperm in the fertilization process; usually remains around the fertilized egg until it is implanted in the wall of the uterus
- zona
- (anatomy) any encircling or beltlike structure
- zonula
- small beltlike zone
- zygodactyl foot
- a bird's foot having the first and fourth toes of each foot directed backward and the second and third forward
- zygomatic process
- a slender process of the temporal bone that strengthens the zygomatic arch