any small opening in the skin or outer surface of an animal


the orifice from the lower left chamber of the heart to the aorta


a mouth or mouthlike opening (especially one created by surgery on the surface of the body to create an opening to an internal organ)


(anatomy) any hollow cylindrical body structure


any of the small tubules that are the excretory units of the vertebrate kidney


the capsule that contains Bowman's capsule and a glomerulus at the expanded end of a nephron


thin double membrane surrounding the glomerulus of a nephron


a small intertwined group of capillaries in the malpighian body; it filters the blood during urine formation


a network of tiny blood vessels between the cerebral surface of the pia mater and the cerebral cortex


a path or channel or duct through or along which something may pass


oewn-auditory_meatus-n oewn-acoustic_meatus-n oewn-ear_canal-n oewn-auditory_canal-n oewn-external_auditory_canal-n

either of the passages in the outer ear from the auricle to the tympanic membrane


a bump on the outside of the humerus where the deltoid muscle attaches


the passages in the nasal cavity formed by the projections of the nasal conchae


the canal in successive vertebrae through which the spinal cord passes


a natural or surgical joining of parts or branches of tubular structures so as to make or become continuous


an aperture or hole that opens into a bodily cavity

the orifice into the aorta from the lower left chamber of the heart


opening for major blood vessels to enter and leave the liver


the spiracle of a cetacean located far back on the skull


an external tracheal aperture in a terrestrial arthropod


oewn-duct-n oewn-epithelial_duct-n oewn-canal-n oewn-channel-n

a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance


a small canal or duct as in some bones and parts of plants


a circular canal in the eye that drains aqueous humor from the anterior chamber of the eye into the anterior ciliary veins


a wide channel containing blood; does not have the coating of an ordinary blood vessel


either of a pair of large venous sinuses in the cranial cavity


a short sinus receiving most of the veins of the heart; empties into the right atrium


an S-shaped dural sinus on the temporal and occipital bones


a paired dural sinus; terminates in the sigmoid sinus


any of various air-filled cavities especially in the bones of the skull


a sinus of the meatuses of the nasal cavity (behind the bridge of the nose)


one of a pair of cavities in the frontal bone


one of a pair of sinuses forming a cavity in the maxilla


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


tiny endothelium-lined passages for blood in the tissue of an organ


a small cavity or space within an organ or in a plant or animal


the dilated portion of a canal or duct especially of the semicircular canals of the ear


any of the cylindrical filaments characteristically growing from the epidermis of a mammal


a hair that does not emerge from the follicle but remains embedded in the skin (usually causing inflammation)


a covering for the body (or parts of it) consisting of a dense growth of threadlike structures (as on the human head); helps to prevent heat loss


a covering over the surface of your head


fine soft dense hair (as the fine short hair of cattle or deer or the wool of sheep or the undercoat of certain dogs)


the fine downy hair covering a human fetus; normally shed during the ninth month of gestation


growth of hair covering the scalp of a human being


the natural margin formed by hair on the head


a line of scalp that can be seen when sections of hair are combed in opposite directions


a V-shaped point in the hairline in the middle of the forehead


a tuft of hair that grows in a different direction from the rest of the hair and usually will not lie flat


oewn-hairdo-n oewn-hairstyle-n oewn-hair_style-n oewn-coiffure-n oewn-coif-n

the arrangement of the hair (especially a woman's hair)


a woman's hairstyle in which the hair gives a puffy appearance


a lock of hair growing (or falling) over the forehead


a prominent forelock (especially one brushed upward from the forehead)


a lock of hair that has been artificially waved or curled


a curl of hair made by dampening a strand of hair and curling it and holding the curl with a clip or bobby pin


a spiral curl plastered on the forehead or cheek


one of many long thin braids of hair radiating from the scalp; popularized by Rastafarians


a border of hair that is cut short and hangs across the forehead


a hair style for women and children; a short haircut all around


a hairdo that creates undulations in the hair


oewn-braid-n oewn-plait-n oewn-tress-n oewn-twist-n

a hairdo formed by braiding or twisting the hair


a roll of hair worn at the nape of the neck


a hairdo characterized by deep regular waves that are made by a heated curling iron


a smooth hair style with the ends of the hair curled inward


a hair style in which the front hair is swept up from the forehead


a hair style that draws the hair back so that it hangs down in back of the head like a pony's tail


a series of waves in the hair made by applying heat and chemicals


a short haircut with hairs standing up like a brush


a closely cropped haircut; usually for men or boys


haircut in which the head is shaved except for a band of hair down the middle of the scalp


a roll of hair brushed back from the forehead


a long tuft of hair left on top of the shaven head


hair resembling thatched roofing material


hair on the face (especially on the face of a man)


the hair growing on the lower part of a man's face


a small tufted beard worn by Emperor Napoleon III


an unshaved growth of hair on the upper lip

he looked younger after he shaved off his mustache


a large bushy moustache (with hair growing sometimes down the sides of the mouth)


oewn-sideburn-n oewn-burnside-n oewn-mutton_chop-n oewn-side-whiskers-n

facial hair that has grown down the side of a man's face in front of the ears (especially when the rest of the beard is shaved off)


a small chin beard trimmed to a point; named for its resemblance to a goat's beard


short stiff hairs growing on a man's face when he has not shaved for a few days


a short pointed beard (named after the artist Anthony Vandyke)


a small patch of facial hair just below the lower lip and above the chin


vulgar term for a woman's pubic hair or genitals


the crustlike surface of a healing skin lesion


a dry scab formed on the skin following a burn or cauterization of the skin


(anatomy) the base of a hollow organ or that part of the organ farthest from its opening


any of several body structure resembling a cord


any bulge or swelling of an anatomical structure or part


a thin tissue or blood sample spread on a glass slide and stained for cytologic examination and diagnosis under a microscope


any of several cytologic smears obtained from different parts of the alimentary tract; obtained by specialized lavage techniques and used mainly to diagnose cancer in those parts


alimentary tract smear of material obtained from the esophagus


alimentary tract smear of material obtained from the stomach


alimentary tract smear of material obtained from the mouth


alimentary tract smear of material obtained from the duodenum


a sample of secretions and superficial cells of the uterine cervix and uterus; examined with a microscope to detect any abnormal cells


any of several cytologic smears obtained from different parts of the lower respiratory tract; used for cytologic study of cancer and other diseases of the lungs


smear taken from the vaginal mucosa for cytological analysis


a bit of tissue or blood or urine that is taken for diagnostic purposes

they collected a urine specimen for urinalysis


a specimen used for cytologic examination and diagnosis


a cord-like tissue connecting two larger parts of an anatomical structure


part of an organism consisting of an aggregate of cells having a similar structure and function


the soft tissue of the body of a vertebrate: mainly muscle tissue and fat


fibrous connective tissue with the fibers arranged in a mesh or net


a cell that produces insulin in the isles of Langerhans in the pancreas


a layer of tissue densely packed with capillaries


animal tissue that constitutes the essential part of an organ as contrasted with e.g. connective tissue and blood vessels


tissue between the cells of a structure or part in plant or animal


a kind of body tissue containing stored fat that serves as a source of energy; it also cushions and insulates vital organs

fatty tissue protected them from the severe cold


a fatty deposit in the intima (inner lining) of an artery; can obstruct blood flow


lumpy deposits of body fat especially on women's thighs etc.


fat on the body of a baby or child; disappears at adolescence


rigid connective tissue that makes up the skeleton of vertebrates


oewn-anklebone-n oewn-astragal-n oewn-astragalus-n oewn-talus-n

the bone in the ankle that articulates with the leg bones to form the ankle joint


the cube shaped bone on the outer side of the tarsus


any of the eight small bones of the wrist of primates


a passageway in the wrist through which nerves and the flexor muscles of the hands pass


the largest wrist bone on the thumb side


oewn-triquetral-n oewn-triquetral_bone-n oewn-os_triquetrum-n oewn-cuneiform_bone-n oewn-pyramidal_bone-n

a wrist bone that articulates with the pisiform and hamate and lunate bones


a small wrist bone that articulates only with the triquetral


the wrist bone on the thumb side of the hand that articulates with the 1st and 2nd metacarpals


the wrist bone between the trapezium and the capitate bones


the wrist bone with a rounded head shape that articulates with the 3rd metacarpus


oewn-hamate-n oewn-hamate_bone-n oewn-unciform_bone-n oewn-os_hamatum-n

the wrist bone in line with the 4th and 5th fingers


any bone that develops within cartilage rather than a fibrous tissue


oewn-cheekbone-n oewn-zygomatic_bone-n oewn-zygomatic-n oewn-malar-n oewn-malar_bone-n oewn-jugal_bone-n oewn-os_zygomaticum-n

the arch of bone beneath the eye that forms the prominence of the cheek


the end of the vertebral column in humans and tailless apes


bone (calcified tissue) surrounding the pulp cavity of a tooth


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


the largest tarsal bone; forms the human heel


large flaring bone forming one half of the pelvis; made up of the ilium and ischium and pubis


a U-shaped bone at the base of the tongue that supports the tongue muscles


the upper and widest of the three bones making up the hipbone


one of the three sections of the hipbone; situated below the ilium


in limbs of vertebrate animals: a long cylindrical bone that contains marrow


oewn-lower_jaw-n oewn-mandible-n oewn-mandibula-n oewn-mandibular_bone-n oewn-submaxilla-n oewn-lower_jawbone-n oewn-jawbone-n oewn-jowl-n

the jaw in vertebrates that is hinged to open the mouth


the posterior part of the mandible that is more or less vertical


a ridge that forms a seam between two parts


the seam at the middle of the hard palate


the joint between the head of the lower jawbone and the temporal bone


any bone that develops within membranous tissue without previous cartilage formation; e.g. the clavicle and bones of the skull


a projection below the mouth of certain mollusks that resembles a chin


any bone of the hand between the wrist and fingers


any bone of the foot between the ankle and the toes


an elongated rectangular bone that forms the bridge of the nose


a small bone; especially one in the middle ear


ossicles of the middle ear that transmit acoustic vibrations from the eardrum to the inner ear


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


a small flat triangular bone in front of the knee that protects the knee joint


one of the three sections of the hipbone; together these two bones form the front of the pelvis


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)


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


either of two flat triangular bones one on each side of the shoulder in human beings


the concavity in the head of the scapula that receives the head of the humerus to form the shoulder joint


a deep concavity in the temporal bone at the root of the zygomatic arch that receives the condyle of the mandible


the outermost point of the spine of the shoulder blade


any of several small round bones formed in a tendon where it passes over a joint


a bone that is of approximately equal dimension in all directions


a bony hollow into which a structure fits


butterfly-shaped bone at the base of the skull


the flat bone that articulates with the clavicles and the first seven pairs of ribs


the large central part of the breastbone


smallest of the three parts of the breastbone; articulates with the corpus sternum and the seventh rib


a thick bone forming the side of the human cranium and encasing the inner ear


the kind and number and arrangement of teeth (collectively) in a person or animal


hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defense


the central cavity of a tooth containing the pulp (including the root canal)


the last upper premolar and first lower molar teeth of a carnivore; having sharp edges for cutting flesh


any of the scrolled spongy bones of the nasal passages in man and other vertebrates


oewn-upper_jaw-n oewn-upper_jawbone-n oewn-maxilla-n oewn-maxillary-n

the jaw in vertebrates that is fused to the cranium


one of the bony segments of the spinal column


a fibrocartilaginous disc serving as a cushion between all of the vertebrae of the spinal column (except between the first two)


the slender arch formed by the temporal process of the cheekbone that bridges to the zygomatic process of the temporal bone


the socket part of the ball-and-socket joint between the head of the femur and the innominate bone


oewn-eye_socket-n oewn-orbit-n oewn-cranial_orbit-n oewn-orbital_cavity-n

the bony cavity in the skull containing the eyeball


a bony socket in the alveolar ridge that holds a tooth


the fatty network of connective tissue that fills the cavities of bones


bone marrow of children and some adult bones that is required for the formation of red blood cells


bone marrow that is yellow with fat; found at the ends of long bones in adults


a membrane in the cochlea that supports the organ of Corti


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


a fibrous scleroprotein in bone and cartilage and tendon and other connective tissue; yields gelatin on boiling


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


delicate connective tissue around individual nerve fibers in nerve


a fibrous scleroprotein found in elastic tissues such as the walls of arteries


tough elastic tissue; mostly converted to bone in adults


(anatomy) a disk of cartilage that serves as a cushion between the ends of bones that meet at a joint


cartilage that is largely composed of fibers like those in ordinary connective tissue


translucent cartilage that is common in joints and the respiratory passages; forms most of the fetal skeleton


vascular tissue capable of filling with blood and becoming rigid


animal tissue consisting predominantly of contractile cells


one of the contractile organs of the body


muscle tissue characterized by transverse stripes


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


that part of a skeletal muscle that is away from the bone that it moves


striated muscle that can be controlled voluntarily


a muscle that draws a body part away from the median line


the abductor muscle of the little finger


a muscle that draws a body part toward the median line


the muscle that adducts and extends the thigh


a muscle that produces or assists in pronation


a muscle (especially in the forearm) that produces or assists in supination


a muscle that serves to lift some body part (as the eyelid or lip)


the muscle that extends the forearm and abducts the ulna in pronation of the wrist


(physiology) a muscle that opposes the action of another

the biceps and triceps are antagonistic muscles


a muscle that contracts while another relaxes

when bending the elbow the biceps are the agonist


a muscle that relaxes while another contracts

when bending the elbow the triceps are the antagonist


a muscle that inserts directly onto the capsule of a joint


a small branch of the triceps that inserts into the capsule of the elbow joint


a muscle that flattens the cheek and retracts the angle of the mouth


a large muscle that raises the lower jaw and is used in chewing


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


a skeletal muscle whose contraction extends or stretches a body part


oewn-quadriceps-n oewn-quadriceps_femoris-n oewn-musculus_quadriceps_femoris-n oewn-quad-n

a muscle of the thigh that extends the leg


tissue consisting of or containing fibers in both animals and plants


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)


a sheet or band of tough fibrous tissue connecting bones or cartilages or supporting muscles or organs


a ligament that attaches part of the liver to the diaphragm and the abdominal wall


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


the sheath of connective tissue that covers a bundle of nerve fibers


the sheath of connective tissue that covers a bundle of muscle fibers


a cord or band of inelastic tissue connecting a muscle with its bony attachment


a skeletal muscle whose contraction bends a joint


an encapsulated neural structure consisting of a collection of cell bodies or neurons


any of the ganglia of the autonomic system whose unmyelinated fibers innervate the internal organs


an autonomic ganglion whose postganglionic fibers are distributed to the parotid gland


a fully differentiated structural and functional unit in an animal that is specialized for some particular function


an organ in its earliest stage of development; the foundation for subsequent development


a bodily organ that is essential for life


an organ (a gland or muscle) that becomes active in response to nerve impulses


an organ that is situated on or near the surface of the body


a main organ that is situated inside the body


oewn-viscera-n oewn-entrails-n oewn-innards-n oewn-insides-n

internal organs collectively (especially those in the abdominal cavity)

`viscera' is the plural form of `viscus'


an organ having nerve endings (in the skin or viscera or eye or ear or nose or mouth) that respond to stimulation


any receptor that responds to stimuli inside the body


any receptor that responds to stimuli outside the body


a sensory structure capable of light reception located on the dorsal side of the diencephalon in various reptiles


a sensory receptor that responds to pressure


a sensory receptor that responds to chemical stimuli


a sensory receptor that responds to heat and cold


all of the components of the organ of hearing including the outer and middle and inner ears


oewn-tongue-n oewn-lingua-n oewn-glossa-n oewn-clapper-n

a mobile mass of muscular tissue covered with mucous membrane and located in the oral cavity


the vocal apparatus of the larynx; the true vocal folds and the space between them where the voice tone is generated


a flap of cartilage that covers the windpipe while swallowing


the externally visible part of the oral cavity on the face and the system of organs surrounding the opening


oewn-trap-n oewn-cakehole-n oewn-hole-n oewn-maw-n oewn-yap-n oewn-gob-n


oewn-mouth-n oewn-oral_cavity-n oewn-oral_fissure-n oewn-rima_oris-n

the opening through which food is taken in and vocalizations emerge


the cavity between the jaws and the cheeks


(obstetrics) uterine cervix that becomes dilated before term and without labor often resulting in miscarriage or premature birth


(anatomy) a natural hollow or sinus within the body


(zoology) the cavity (in birds, reptiles, amphibians, most fish, and monotremes but not other mammals) at the end of the digestive tract into which the intestinal, genital, and urinary tracts open


any of various bodily cavities leading to another cavity (as of the ear or vagina)


the central cavity of the bony labyrinth of the ear


the tissue (covered by mucous membrane) of the jaws that surrounds the bases of the teeth


an oval sensory end organ on the surface of the tongue


an epithelial cell in a taste bud that activates sensory fibers of the facial nerve or the glossopharyngeal nerve or the vagus nerve


any of the organs involved in speech production


either of two fleshy folds of tissue that surround the mouth and play a role in speaking


a tooth situated at the front of the mouth

his malocclusion was caused by malposed anteriors


a tooth situated at the back of the mouth


a tooth that has grown in a faulty position


any of the 32 teeth that replace the deciduous teeth of early childhood and (with luck) can last until old age


oewn-primary_tooth-n oewn-deciduous_tooth-n oewn-baby_tooth-n oewn-milk_tooth-n

one of the first temporary teeth of a young mammal (one of 20 in children)


oewn-canine-n oewn-canine_tooth-n oewn-eyetooth-n oewn-eye_tooth-n oewn-dogtooth-n oewn-cuspid-n

one of the four pointed conical teeth (two in each jaw) located between the incisors and the premolars


a tooth having two cusps or points; located between the incisors and the molars


small elevation on the grinding surface of a tooth


a tooth for cutting or gnawing; located in the front of the mouth in both jaws


grinding tooth with a broad crown; located behind the premolars


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)


the part of a tooth above the gum that is covered with enamel


the embedded part of a bodily structure such as a tooth, nail, or hair


the passage in the root of a tooth through which its nerve and blood vessels enter the pulp cavity


hard white substance covering the crown of a tooth


a specialized bony substance covering the root of a tooth


oewn-tonsil-n oewn-palatine_tonsil-n oewn-faucial_tonsil-n oewn-tonsilla-n

either of two masses of lymphatic tissue one on each side of the oral pharynx


a small pendant fleshy lobe at the back of the soft palate


a muscular flap that closes off the nasopharynx during swallowing or speaking


the upper surface of the mouth that separates the oral and nasal cavities


a flat wing-shaped process or winglike part of an organism


the part of the upper or lower jawbones in which the teeth are set


a ridge that forms the borders of the upper and lower jaws and contains the sockets of the teeth


the inner membrane of embryos in higher vertebrates (especially when covering the head at birth)


any membrane that functions for the protection or nourishment or respiration or excretion of a developing fetus


the eye unaided by any optical instrument that alters the power of vision or alters the apparent size or distance of objects

it is not safe to look directly at the sun with the naked eye


in insects and some crustaceans: composed of many light-sensitive elements each forming a portion of an image


any of the numerous small cone-shaped eyes that make up the compound eyes of some arthropods


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


a highly vascular membrane in the eye between the retina and the sclera; a dark pigmentation minimizes the scattering of light inside the eye


the part of the tunic of the eye between the choroid coat and the iris


a flap of tissue that protects what it covers


either of two folds of skin that can be moved to cover or open the eye


either of the corners of the eye where the upper and lower eyelids meet


a vertical fold of skin over the nasal canthus; typical for many east Asian peoples; sometimes occurs in Down's syndrome


a protective fold of skin in the eyes of reptiles and birds and some mammals


any of the short curved hairs that grow from the edges of the eyelids


a transparent lubricating mucous membrane that covers the eyeball and the under surface of the eyelid


the part of the conjunctiva covering the anterior face of the sclera and the surface epithelium of the cornea


the part of the conjunctiva lining the posterior surface of the eyelids; continuous with the bulbar conjunctiva


a slightly elevated elastic tissue deposit in the conjunctiva that may extend to the cornea but does not cover it


the ball-shaped capsule containing the vertebrate eye


one of the small muscles of the eye that serve to rotate the eyeball


oewn-abducens_muscle-n oewn-lateral_rectus_muscle-n oewn-lateral_rectus-n oewn-rectus_lateralis-n

the ocular muscle whose contraction turns the eyeball outward


the ocular muscle whose contraction turns the eyeball down and medially


the ocular muscle whose contraction turns the eyeball medially


the ocular muscle whose contraction turns the eyeball upward and medially


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


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


a whitish deposit in the shape of an arc that is sometimes seen in the cornea


the part of the eye that contains the iris and ciliary body and choroid


a tubule that drains excess aqueous humor


the limpid fluid within the eyeball between the cornea and the lens


the clear colorless transparent jelly that fills the posterior chamber of the eyeball


(anatomy) a muscular partition separating the abdominal and thoracic cavities; functions in respiration


oewn-eardrum-n oewn-tympanum-n oewn-tympanic_membrane-n oewn-myringa-n

the membrane in the ear that vibrates to sound


vascular membrane that lines the inner surface of long bones


thin epithelial membrane lining the ventricles of the brain and the spinal cord canal


the membrane that forms around a fertilized ovum and prevents penetration by additional spermatozoon


the transparent membrane enveloping the vitreous humor of the eye and separating it from the retina


the innermost membrane of an organ (especially the inner lining of an artery or vein or lymphatic vessel)


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


the contractile aperture in the center of the iris of the eye; resembles a large black dot


biconvex transparent body situated behind the iris in the eye; its role (along with the cornea) is to focus light on the retina


the tissue that surrounds the lens nucleus


the central structure of the lens that is surrounded by the cortex


the sense organ for hearing and equilibrium


the part of the ear that is responsible for sensations of sound


a complex system of interconnecting cavities; concerned with hearing and equilibrium


the sensory structures of the inner ear including the labyrinthine receptors and the cochlea; contained within the bony labyrinth


cavity in the petrous part of the temporal bone that contains the membranous labyrinth


the bodily fluid that fills the membranous labyrinth of the inner ear


the bodily fluid that fills the space between the bony labyrinth and the membranous labyrinth of the inner ear


a small pouch into which the semicircular canals open


a small sac or pouch (especially the smaller chamber of the membranous labyrinth)


the central conical bony pillar of the cochlea


the hearing organ of the inner ear; contains receptors that respond to sound waves


organs mediating the labyrinthine sense; concerned with equilibrium


one of three tube loops filled with fluid and in planes nearly at right angles with one another; concerned with equilibrium


a receptor in a muscle that responds to stretching of the muscle tissue


the fleshy pendulous part of the external human ear


the externally visible cartilaginous structure of the external ear


a small cartilaginous flap in front of the external opening of the ear


an auricle deformed by injury; common among boxers


an eardrum with a hole or tear in it; can interfere with normal hearing and cause other ear problems


a slight rounded elevation where the malleus attaches to the eardrum


the part of the thoracic cavity between the lungs that contains the heart and aorta and esophagus and trachea and thymus


the main cavity of the ear; between the eardrum and the inner ear


either of the paired tubes connecting the middle ears to the nasopharynx; equalizes air pressure on the two sides of the eardrum


a small opening covered with membrane (especially one in the bone between the middle and inner ear)


oewn-fenestra_ovalis-n oewn-fenestra_vestibuli-n oewn-oval_window-n oewn-fenestra_of_the_vestibule-n

fenestra that has the base of the stapes attached to it


oewn-fenestra_rotunda-n oewn-fenestra_cochleae-n oewn-round_window-n oewn-fenestra_of_the_cochlea-n


a thin membrane that is one of the calcified layers that form bones


a tenuous mesoblastic membrane surrounding the lens of the eye


a small bone in the middle ear between the malleus and the stapes


the stirrup-shaped ossicle that transmits sound from the incus to the 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


a membrane (one of 3) that envelops the brain and spinal cord


mucus-secreting membrane lining all body cavities or passages that communicate with the exterior


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


oewn-gland-n oewn-secretory_organ-n oewn-secretor-n oewn-secreter-n

any of various organs that synthesize substances needed by the body and release it through ducts or directly into the bloodstream


a cutaneous gland that secretes sebum (usually into a hair follicle) for lubricating hair and skin


a long sebaceous gland that lubricates the eyelids

bacterial infection of a Meibomian gland produces a stye


one of the sebaceous glands on the areolae of the breast that lubricate the breast during breast-feeding


a gland that secretes externally through a duct


oewn-digestive_system-n oewn-gastrointestinal_system-n oewn-systema_alimentarium-n oewn-systema_digestorium-n

the system that makes food absorbable into the body


the system of glands that produce endocrine secretions that help to control bodily metabolic activity


any of the glands of the endocrine system that secrete hormones directly into the bloodstream


any one of four endocrine glands situated above or within the thyroid gland


a small duct that conveys sweat from a sudoriferous gland to the surface of the skin


any of the glands in the skin that secrete perspiration


a large sweat gland that produces both a fluid and an apocrine secretion; in human beings located in hairy regions of the body


a small sweat gland that produces only a fluid; restricted to the human skin


either of a pair of complex endocrine glands situated near the kidney


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


any of the glands in the eyes that secrete tears


any of several small ducts that carry tears from the lacrimal glands


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


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


a duct that carries tears from the lacrimal sac to the nasal cavity


a ductless glandular organ at the base of the neck that produces lymphocytes and aids in producing immunity; atrophies with age


either of two bean-shaped excretory organs that filter wastes (especially urea) from the blood and excrete them and water in urine

urine passes out of the kidney through ureters to the bladder


an organ that separates waste substances from the blood and discharges them


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


a blood vessel that carries blood from the heart to the body


a branch of the maxillary artery that supplies the alveolar process


the alveolar artery that goes through the mandibular canal to supply the lower teeth


the alveolar artery that supplies the upper teeth


the terminal branch of the facial artery


the large trunk artery that carries blood from the left ventricle of the heart to branch arteries


the ascending part of the aorta as it emerges from the left ventricle


the part of the aorta that arches and turns downward


the descending part of the aorta that branches into the thoracic and abdominal aortae


a branch of the descending aorta; divides into the iliac arteries


the branch of the ileocolic artery that supplies the vermiform appendix


one of the small thin-walled arteries that end in capillaries


a branch of the internal pudendal artery of males that supplies the bulb of the penis


a branch of the internal pudendal artery in females that supplies the bulb of the vestibule


the branch of the ileocolic artery that supplies the ascending colon


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


an unpaired artery; supplies the pons and cerebellum and the back part of the cerebrum and the inner ear


the main artery of the upper arm; a continuation of the axillary artery; bifurcates into the radial and ulnar arteries at the elbow


branch of the brachial artery beginning below the elbow and extending down the forearm around the wrist and into the palm


a branch of the maxillary artery that supplies blood to the buccinator muscle and the cheek


either of two major arteries of the neck and head; branches from the aorta


runs upward in the neck and divides into the external and internal carotid arteries


the branch of the carotid artery that supplies blood to the face and tongue and external parts of the head


the branch of the carotid artery that supplies blood to the brain and eyes and internal parts of the head


a chemoreceptor located near the bifurcations of the carotid arteries; monitors oxygen content of the blood and helps control respiration


oewn-celiac_trunk-n oewn-celiac_artery-n oewn-truncus_celiacus-n oewn-arteria_celiaca-n

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


a branch of the ophthalmic artery; enters the eyeball with the optic nerve


the inferior branch of the cerebellar artery


the superior branch of the cerebellar artery


any of the arteries supplying blood to the cerebral cortex


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


one of two branches of the internal carotid artery; divides into three branches


arises from the basilar artery; divides into three branches


an artery that supplies the muscles of the neck


an artery that supplies the choroid plexus


one of several arteries supplying the choroid coat of the eye


a ring of arteries at the base of the brain


an artery that supplies the hip joint and thigh muscles


an artery that supplies the shoulder joint and shoulder muscles


an artery that supplies the lower abdominal walls and skin and the sartorius muscle


an artery that serves the muscles of the shoulder and scapular area


any of three arteries in the brain that make up the circle of Willis


the artery that branches from the aorta to supply blood to the heart


the branch of the coronary artery that supplies the muscles of the atria


arises from the right aortic sinus; supplies the right side of the heart


arises from the left aortic sinus; supplies the left side of the heart


a branch of the hepatic artery; supplies the gall bladder and the surface of the liver


arteries in the hand and foot that supply the fingers and toes


one of three arteries supplying the anterior walls of the abdomen


a branch of the ophthalmic artery supplying structures in and around the nasal capsule


an artery that originates in the external carotid and gives off branches that supply the neck and face


the chief artery of the thigh; a continuation of the external iliac artery


a continuation of the femoral artery that branches to supply the legs and feet


the arteries that supply the walls of the stomach


a branch of the hepatic artery that supplies the pyloric portion of the stomach on the lesser curvature


a branch of the celiac artery that supplies the lesser curvature of the stomach and the abdominal part of the esophagus


several small arteries branching off of the splenic artery and going to the greater curvature of the stomach


branches of the internal iliac artery that supply the hip joint and gluteal region


branch of the superior mesenteric artery that supplies the ileum


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


one of the large arteries supplying blood to the pelvis and legs


terminal branches of the abdominal aorta


the outer branch of the common iliac artery on either side of the body; becomes the femoral 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


an artery that originates in the internal iliac artery and supplies the pelvic muscles and bones


an artery that originates from the maxillary artery and supplies structures below the orbit (from lower eyelid to upper lip)


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


several arteries and supplying the intercostal spaces of the rib cage


an artery that is a branch of the superior mesenteric artery that supplies the jejunum


an artery that is a branch of the facial artery that supplies the lips of the mouth


an artery that is a branch of the facial artery that supplies the lower lip


an artery that is a branch of the facial artery that supplies the upper lip


an artery that is a branch of the basilar artery that supplies the labyrinth


an artery that originates from the ophthalmic artery and supplies the lacrimal gland and rectal eye muscles and the upper eyelid and the forehead


either of two arteries that supply blood to the larynx


an artery that originates from the celiac trunk and supplies blood to the spleen


an artery originating from the external carotid artery and supplying the under side of the tongue


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


either of two arteries branching from the external carotid artery and supplying structure of the face


the maxillary artery that supplies deep structure of the face and some of the meninges


any of three arteries supplying the meninges of the brain and neighboring structures


branch of the anterior ethmoidal artery that supplies meninges in the anterior cranial fossa


branch of the maxillary artery; its branches supply meninges


branch of the ascending pharyngeal artery that supplies the dura mater of the posterior cranial fossa


one of two branches of the aorta that pass between the two layers of the mesentery to the intestines


arises near the lower end of the aorta and supplies the large intestine


originates from the upper part of the aorta that supplies the small intestines and the cecum and the colon


dorsal and plantar arteries to the metatarsal region of the foot


an artery that supplies the abdomen and intercostal muscles


an artery that supplies the medullary cavity of the long bone


a branch of the internal carotid artery that supplies the eye and neighboring structures


the artery that branches from the aorta and supplies blood to the ovaries


one of several arteries supplying the face


a branch of the splenic artery that supplies the pancreas


a branch of the internal pudendal artery that supplies superficial structures of the perineum


arteries supplying the external genital organs of humans


one of two arteries (branches of the pulmonary trunk) that carry venous blood from the heart to the lungs


the artery that carries venous blood from the right ventricle of the heart and divides into the right and left pulmonary arteries


one of the arteries supplying the rectal area


an artery originating from the abdominal aorta and supplying the kidneys and adrenal glands and ureters


either of two arteries that supply blood to the neck and arms


any of the three arteries on either side of the brain supplying the cortex of the temporal lobe


temporal artery that goes to the anterior part of the cerebral cortex of the temporal lobe


temporal artery that goes to the middle part of the cerebral cortex of the temporal lobe


temporal artery that supplies the posterior part of the cortex of the temporal lobe


a branch of the aorta supplying the testicles


large artery that branches from the brachial artery to supply the muscles of the forearm and wrist and hand


a branch of the internal iliac artery that supplies the uterus and the upper part of the vagina


a branch of the internal iliac that provides blood for the vagina and the base of the bladder and the rectum


the first branch of the subclavian artery; divided into four parts


a vein that passes along the radial edge of the forearm and joins the cephalic vein near the elbow


a vein formed by the union of the 4th to 7th posterior intercostal veins; empties into the azygos 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


a vein accompanying another structure; a vein may accompany an artery in such a way that the arterial pulses aid venous return


either of two communicating veins serving the brain


a short vein formed by the supraorbital vein and the supratrochlear vein and continuing as the facial vein


a vein that accompanies the ascending cervical artery and opens into the vertebral vein


a vein that accompanies the appendicular artery and empties into the ileocolic vein


veins that receive blood from interlobular veins of kidney and rectal venules


a continuation of the basilic vein and brachial vein that becomes the subclavian 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


a large vein passing along the medial surface of the temporal lobe and emptying into the great cerebral vein


a vein that drains the back of the hand and forearm and empties into the axillary vein


one of a number of veins draining the spongy substance of the vertebrae and emptying into the anterior internal vertebral venous plexus


two veins in either arm that accompany the brachial artery and empty into the axillary vein


veins formed by the union of the internal jugular and subclavian veins


veins serving the bronchi; empty into the azygos vein


any of the major venous channels in primitive adult vertebrates and in embryos of higher vertebrates


a major drainage channel from the cephalic part of the body


a major drainage channel from the caudal part of the body


the major return channels to the heart; formed by anastomosis of the anterior and posterior cardinal veins


terminal branches of the hepatic veins that lie in the hepatic lobules and receive blood from the liver sinusoids


vein formed by the union of the retinal veins; accompanies central arteries of the retina in the optic nerve


a single draining vein; on the right it empties into the inferior vena cava; on the left it empties into the left renal vein


a large vein of the arm that empties into the axillary vein


any of several veins serving the cerebral hemispheres of the brain


accompanies the anterior cerebral artery and empties into the basal vein


a continuation of the angular vein; unites with the retromandibular vein before emptying into the internal jugular vein


a cerebral vein formed by the two internal cerebral veins and continuing into the sinus rectus


veins that drain the undersurface of the cerebral hemispheres and empty into the cavernous and transverse sinuses


two paired veins passing caudally near the midline and uniting to form the great cerebral vein


accompanies the middle cerebral artery deep in the Sylvian fissure; empties into the basal vein


a large vein along the line of the Sylvian fissure to the cavernous sinus


a cerebral vein that drains the dorsal convexity of the cerebral hemisphere and empties into the cavernous sinus


a vein that accompanies an artery of the same name


either of two veins serving the choroid coat of the eye


small veins coming from the ciliary body


any of several curved parallel veins accompanying arteries of the same name


either of two veins that accompany arteries of the same name serving the hip and thigh


vein formed by union of facial vein and the retromandibular vein and emptying into the jugular vein


one of several veins connecting intercostal veins with the lateral thoracic vein or the thoracoepigastric vein


one of a number of veins in the subcutaneous tissue that empty into deep veins


one of the veins serving the fingers or toes


one of the veins serving the spongy part of the cranial bones


vein that is a tributary of the subclavian vein or external jugular vein and accompanies the descending scapular artery


one of several connecting veins in the scalp and head that drain blood from sinuses in the dura mater to veins outside the skull


veins serving the anterior walls of the abdomen


veins that accompany the superior epigastric artery


small veins in the sclera near the corneal margin; empty into the anterior ciliary veins


small veins from the esophagus emptying into the brachiocephalic vein or the azygos veins


veins that drain the ethmoidal sinuses and empty into the superior ophthalmic vein


one of the veins that drain the external nose and empty into the angular or facial vein


a vein that accompanies the femoral artery in the same sheath; a continuation of the popliteal vein; becomes the external iliac vein


one of several veins draining the stomach walls


one of two veins serving the great curvature of the stomach


veins that drain blood from structures around the knee; empty into the popliteal vein


a small rounded structure; especially that at the end of the penis or clitoris


small mass of erectile tissue at the end of the body of the clitoris


the conical mass of erectile tissue that forms the head of the penis


veins draining the gluteal muscles on either side of the body


a continuation of the left ascending lumbar vein; crosses the midline at the 8th vertebra and empties into the azygos vein


any of several veins draining the walls of the anal canal and rectum


a vein that drains the liver; empties into the vena cava


a vein that unites with the external iliac vein to form the common iliac vein


a vein that drains the end of the ileum and the appendix and the cecum and the lower part of the ascending colon


a continuation of the femoral vein; unites with the internal iliac vein to form the 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


one of three veins draining the pelvic area


veins connecting the dorsal and palmar veins of the hand or the dorsal and plantar veins of the foot


several veins draining the intercostal spaces of the rib cage


one of several veins accompanying spinal nerves


veins in the neck that return blood from the head


arises below the chin from veins draining the lower face; joins the external jugular vein


formed by the junction of the posterior auricular and the retromandibular veins; empties into the subclavian vein


a continuation of the sigmoid sinus of the dura mater; joins the subclavian vein to form the brachiocephalic vein


a tributary of the facial vein that drains the lower lip


a tributary of the facial vein that drains the upper lip


drains the lacrimal gland; empties into the superior ophthalmic vein


arises from a union of veins from the gastric cardia; runs in the lesser omentum; empties into the portal 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


veins that drain the posterior body wall and the lumbar vertebral venous plexuses


posterior continuation of the pterygoid plexus; joins the superficial temporal vein to form the retromandibular vein


veins at accompany the meningeal arteries


a tributary of the portal vein passing from the intestine between the two layers of mesentery


dorsal and plantar branches of veins serving the metatarsal region of the foot


veins that drain the upper abdominal wall and the lower intercostal spaces and the abdomen


a vein located in the anterior medial part of the orbit; connects the superior ophthalmic with the angular vein


a tributary of the coronary sinus; on the posterior wall of the left atrium


a vein formed by the union of tributaries that drain the hip joints and thigh muscles; empties into the internal iliac vein


either of two veins that serve the eye; empties into the cavernous sinus


a vein that drains a venous network in the floor and medial wall of the eye socket


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


one of the veins that drain the ovaries; the right opens into the inferior vena cava; the left opens into the left renal vein


a vein that drains the region of the palate and empties into the facial vein


veins draining the pancreas and emptying into the superior mesenteric and splenic veins


small veins arising in skin around the navel; terminate as accessory portal veins


parotid branches of the facial vein; they drain part of the parotid gland and empty into the retromandibular vein


veins that drain the pectoral muscles and empty into the subclavian vein


veins that accompany the perforating arteries; drain leg muscles; empty into the deep femoral vein


several small veins from the pericardium


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


veins from the pharyngeal plexus that empty into the internal jugular vein


either of two veins that drain the diaphragm


a vein arising in the knee and ascending to become the femoral vein


system of veins that carry blood from the abdominal organs to the liver


oewn-portal_vein-n oewn-hepatic_portal_vein-n oewn-portal-n oewn-vena_portae-n

a short vein that carries blood into the liver


arises near the apex of the heart and empties into the coronary sinus


any of four veins that carry arterial blood from the lungs to the left atrium of the heart


either of two pulmonary veins (left and right) returning blood from the inferior lobes of the lungs


either of two pulmonary veins (left and right) returning blood from the superior lobes of the lungs


receives veins from the upper surfaces of the stomach and empties into the portal vein


superficial veins ascending the radial side of the forearm; combines with the ulnar veins to form the brachial vein


veins that accompany renal arteries; open into the vena cava at the level of the 2nd lumbar vertebra


posterior branch of the facial vein; formed by temporal veins in front of the ear


either of two chief superficial veins of the leg that drain blood from the foot


the longest vein in the body; runs from foot to the groin where it joins the femoral vein


a vein running from the foot up the back of the leg to the knee


tributaries of the anterior ciliary veins that drain the sclera of the eye


veins passing from the scrotum to the pudendal veins


tributaries of the inferior mesenteric vein; drains the sigmoid colon


a vein formed by several small veins on the surface of the spleen; joins the superior mesenteric to form the portal vein


a star-shaped group of venules in the renal cortex


drains the sternocleidomastoid muscle; empties into the internal jugular vein


a vein that drains the tympanic cavity and empties into the retromandibular vein


a continuation of the axillary vein; joins the internal jugular to form the brachiocephalic vein


drains the front of the scalp; unites with the supratrochlear vein to form the angular vein


drains the front of the scalp; unites with the supraorbital vein to form the angular vein


any of several veins draining the temporal region


temporal veins that empty into the pterygoid plexus


arises near the eye; joins the superficial temporal veins to form the retromandibular vein


join the middle temporal vein to empty into the retromandibular vein


a vein serving the thalamus and corpus striatum


a vein arising from the region of the superficial epigastric vein and opening into the axillary vein or thoracic vein


a long vein that helps to form the internal cerebral vein


any of several small veins draining blood from the thyroid area


any of several veins on each side that drain the thyroid gland and empty into the innominate vein


a vein on each side that drains the lateral part of the thyroid and empties into the internal jugular vein


a vein on each side that drains the upper part of the thyroid and empties into the internal jugular vein


veins of the lower leg; empty into the popliteal vein


veins from the tympanic cavity that empty into the retromandibular vein


a vein in the umbilical cord; returns nutrient blood from the placenta to the fetus


one of two veins on each side that arise from the uterine plexus and empty into the internal iliac vein


a muscular sac attached to the liver that stores bile (secreted by the liver) until it is needed for digestion


the upper region of the abdomen just below the lowest ribs on either side of the epigastrium


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


any of the many tiny canals that contain blood vessels and connective tissue and that form a network in bone


the duct that drains bile from the liver


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


a duct formed by the hepatic and cystic ducts; opens into the duodenum


excretory ducts of the liver; empty into the hepatic ducts


a large elongated exocrine gland located behind the stomach; secretes pancreatic juice and insulin


a duct connecting the pancreas with the intestine


either of two saclike respiratory organs in the chest of vertebrates; serves to remove carbon dioxide and provide oxygen to the blood


any of the three lobes of the right lung or the two lobes of the left lung


the thin serous membrane around the lungs and inner walls of the chest


pleura that lines the inner chest walls and covers the diaphragm


the cavity in the thorax that contains the lungs and heart


the small potential space between the parietal and visceral layers of the pleura


the hollow muscular organ located behind the sternum and between the lungs; its rhythmic contractions move the blood through the body

he stood still, his heart thumping wildly


enlarged heart commonly found among athletes trained for endurance


a heart (as of mammals and birds and reptiles) having two auricles


oewn-pacemaker-n oewn-cardiac_pacemaker-n oewn-sinoatrial_node-n oewn-SA_node-n

a specialized bit of heart tissue that controls the heartbeat


a movable piece of tissue partly connected to the body


the muscle tissue of the heart; adapted to continued rhythmic contraction


any of several muscles associated with the atrioventricular valves

the papillary muscles contract during systole to prevent regurgitation of blood into the atria


oewn-atrioventricular_bundle-n oewn-bundle_of_His-n oewn-atrioventricular_trunk-n oewn-truncus_atrioventricularis-n

a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract


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


the middle muscular layer of the heart wall


a specialized cardiac muscle fiber that is part of the Purkinje network


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


a triangular area of the front of the chest (determined by percussion); corresponds to the part of the heart not covered by the lungs


a chamber of the heart that receives blood from an atrium and pumps it to the arteries


the chamber on the left side of the heart that receives arterial blood from the left atrium and pumps it into the aorta


the chamber on the right side of the heart that receives venous blood from the right atrium and pumps it into the pulmonary trunk


a small conical pouch projecting from the upper anterior part of each atrium of the heart


a pouch projecting from the top front of each atrium of the heart


any chamber that is connected to other chambers or passageways (especially one of the two upper chambers of the heart)


the upper chamber of each half of the heart


the right upper chamber of the heart that receives blood from the venae cavae and coronary sinus


the left upper chamber of the heart that receives blood from the pulmonary veins


valve with two cusps; situated between the left atrium and the left ventricle


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


either of two heart valves through which blood flows from the atria to the ventricles; prevents return of blood to the atrium


a semilunar valve between the left ventricle and the aorta; prevents blood from flowing from the aorta back into the heart


a semilunar valve between the right ventricle and the pulmonary artery; prevents blood from flowing from the artery back into the heart


a heart valve with cusps shaped like half-moons; prevents blood from flowing back into the heart


a valve to control one-way flow of blood


a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it


oewn-stomach-n oewn-tummy-n oewn-tum-n oewn-breadbasket-n

an enlarged and muscular saclike organ of the alimentary canal; the principal organ of digestion


the region lying on or over the stomach (just below the sternum)


the opening into the stomach and that part of the stomach connected to the esophagus


the interconnected system of spaces and vessels between body tissues and organs by which lymph circulates throughout the body


a vascular duct that carries lymph which is eventually added to the venous blood circulation


any of the lymphatic vessels that convey chyle from the small intestine to the thoracic duct


a structure composed of or provided with blood vessels


oewn-liquid_body_substance-n oewn-bodily_fluid-n oewn-body_fluid-n oewn-humor-n oewn-humour-n


liquid containing proteins and electrolytes including the liquid in blood plasma and interstitial fluid

the body normally has about 15 quarts of extracellular fluid


liquid found between the cells of the body that provides much of the liquid environment of the body


liquid contained inside the cell membranes (usually containing dissolved solutes)


a milky substance found in certain cancerous growths


a clear liquid in the cell nucleus in which the nucleolus and chromatin and other structures are dispersed


produced by mammary glands of female mammals for feeding their young


milk secreted by a woman who has recently given birth


milky fluid secreted for the first day or two after parturition


the fluid-filled cavity that surrounds the developing embryo


the serous fluid in which the embryo is suspended inside the amnion

before a woman gives birth her waters break


the fluid (red in vertebrates) that is pumped through the body by the heart and contains plasma, blood cells, and platelets

blood carries oxygen and nutrients to the tissues and carries away waste products


except for the pulmonary artery the arterial blood is rich in oxygen


human blood cells (usually just the red blood cells) that have the same antigens


the blood group whose red cells carry the A antigen


the blood group whose red cells carry the B antigen


the blood group whose red cells carry both the A and B antigens


the blood group whose red cells carry neither the A nor B antigens

people with type O blood are universal donors


the blood group (approximately 85% of people) whose red cells have the Rh factor (Rh antigen)


the blood group whose red cells lack the Rh factor (Rh antigen)


the blood considered as the seat of vitality


the blood flowing through the circulatory system


a lump of material formed from the content of a liquid


a semisolid mass of coagulated red and white blood cells


blood obtained from the umbilical cord at birth


flow of blood from the uterus; occurs at roughly monthly intervals during a woman's reproductive years


except in the pulmonary vein venous blood is rich in carbon dioxide and poor in oxygen


blood that has not been modified except for the addition of an anticoagulant

whole blood is normally used in blood transfusions


an amber, watery fluid, rich in proteins, that separates out when blood coagulates


the colorless watery fluid of the blood and lymph that contains no cells, but in which the blood cells (erythrocytes, leukocytes, and thrombocytes) are suspended


blood serum containing antibodies against specific antigens; provides immunity to a disease


a milky fluid consisting of lymph and emulsified fats; formed in the small intestine during digestion of ingested fats


a thin coagulable fluid (similar to plasma but) containing white blood cells (lymphocytes) and chyle; is conveyed to the blood stream by lymphatic vessels


oewn-semen-n oewn-seed-n oewn-seminal_fluid-n oewn-ejaculate-n oewn-cum-n oewn-come-n

the thick white fluid containing spermatozoa that is ejaculated by the male genital tract


dark protective fluid ejected into the water by cuttlefish and other cephalopods


a functionally specialized substance (especially one that is not a waste) released from a gland or cell


saline fluid secreted by lacrimal glands; lubricates the surface of the eyeball


a drop of the clear salty saline solution secreted by the lacrimal glands


the structures that secrete and drain tears from the eye


digestive secretions of the stomach glands consisting chiefly of hydrochloric acid and mucin and the enzymes pepsin and rennin and lipase


a fluid secreted into the duodenum by the pancreas; important for breaking down starches and proteins and fats


a digestive juice secreted by the liver and stored in the gallbladder; aids in the digestion of fats


a humor that was once believed to be secreted by the kidneys or spleen and to cause sadness and melancholy


a humor that was once believed to be secreted by the liver and to cause irritability and anger


the secretion of an endocrine gland that is transmitted by the blood to the tissue on which it has a specific effect


secretions by glands lining the walls of the intestines


a catecholamine precursor of epinephrine that is secreted by the adrenal medulla and also released at synapses


oewn-adrenocorticotropic_hormone-n oewn-adrenocorticotrophic_hormone-n oewn-ACTH-n oewn-adrenocorticotropin-n oewn-adrenocorticotrophin-n oewn-corticotropin-n oewn-corticotrophin-n

a hormone produced by the anterior pituitary gland that stimulates the adrenal cortex


oewn-epinephrine-n oewn-epinephrin-n oewn-adrenaline-n oewn-Adrenalin-n

a catecholamine secreted by the adrenal medulla in response to stress (trade name Adrenalin); stimulates autonomic nerve action


hormones that affect gastrointestinal functioning


polypeptide hormone secreted by the mucous lining of the stomach; when peptides and amino acids are present in the small intestine the secretion of gastric acid is stimulated


a gastrointestinal hormone that stimulates the secretion of pancreatic enzymes and the contraction and emptying of the gall bladder; its release is stimulated by the presence of fatty acids and amino acids in the small intestine


a gastrointestinal hormone that stimulates the secretion of water and bicarbonate from the pancreas and bile ducts whenever the stomach empties too much acid into the small intestine


a gastrointestinal hormone produced by epithelial cells lining the fundus of the stomach; appears to be a stimulant for appetite and feeding, but is also a strong stimulant of growth hormone secretion from the anterior pituitary


a gastrointestinal hormone that apparently participates in controlling smooth muscle contractions in the stomach and small intestine


a hormone secreted by the pancreas; stimulates increases in blood sugar levels in the blood (thus opposing the action of insulin)


oewn-gonadotropin-n oewn-gonadotrophin-n oewn-gonadotropic_hormone-n oewn-gonadotrophic_hormone-n

hormone secreted by the anterior pituitary gland and placenta; stimulates the gonads and controls reproductive activity


hormone secreted by the isles of Langerhans in the pancreas; regulates storage of glycogen in the liver and accelerates oxidation of sugar in cells


trade names for forms of insulin that are used to treat diabetes mellitus


a form of insulin (trade name Humulin) made from recombinant DNA that is identical to human insulin; used to treat diabetics who are allergic to preparations made from beef or pork insulin


a hormone that is released by nerve impulses (e.g., norepinephrine or vasopressin)


hormone secreted by the posterior pituitary gland (trade name Pitocin); stimulates contractions of the uterus and ejection of milk


hormone synthesized and released into the blood stream by the parathyroid glands; regulates phosphorus and calcium in the body and functions in neuromuscular excitation and blood clotting


hormone secreted by the corpus luteum during the last days of pregnancy; relaxes the pelvic ligaments and prepares the uterus for labor


oewn-releasing_hormone-n oewn-RH-n oewn-releasing_factor-n oewn-hypothalamic_releasing_hormone-n oewn-hypothalamic_releasing_factor-n

any of several hormones produced in the hypothalamus and carried by a vein to the anterior pituitary gland where they stimulate the release of anterior pituitary hormones; each of these hormones causes the anterior pituitary to secrete a specific hormone


oewn-somatotropin-n oewn-somatotrophin-n oewn-somatotropic_hormone-n oewn-somatotrophic_hormone-n oewn-STH-n oewn-human_growth_hormone-n oewn-growth_hormone-n

a hormone produced by the anterior pituitary gland; promotes growth in humans


trade name of a synthetic human growth hormone given to children deficient in the hormone; use by athletes and weightlifters is banned


hormone secreted by the thymus; stimulates immunological activity of lymphoid tissue


any of several closely related compounds that are produced by the thyroid gland and are active metabolically


thyroid hormone that tends to lower the level of calcium in the blood plasma and inhibit resorption of bone


oewn-thyroxine-n oewn-thyroxin-n oewn-tetraiodothyronine-n oewn-T-n

hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells


thyroid hormone similar to thyroxine but with one less iodine atom per molecule and produced in smaller quantity; exerts the same biological effects as thyroxine but is more potent and briefer


oewn-vasopressin-n oewn-antidiuretic_hormone-n oewn-ADH-n oewn-Pitressin-n

hormone secreted by the posterior pituitary gland (trade name Pitressin) and also by nerve endings in the hypothalamus; affects blood pressure by stimulating capillary muscles and reduces urine flow by affecting reabsorption of water by kidney tubules


any physiologically active internal secretion especially one of uncertain classification


amine formed from histidine that stimulates gastric secretions and dilates blood vessels; released by the human immune system during allergic reactions


a potent substance that acts like a hormone and is found in many bodily tissues (and especially in semen); produced in response to trauma and may affect blood pressure and metabolism and smooth muscle activity


viscid lubricating fluid secreted by the membrane lining joints and tendon sheaths etc.


protective secretion of the mucous membranes; in the gut it lubricates the passage of food and protects the epithelial cells; in the nose and throat and lungs it can make it difficult for bacteria to penetrate the body through the epithelium


expectorated matter; saliva mixed with discharges from the respiratory passages; in ancient and medieval physiology it was believed to cause sluggishness


a clear liquid secreted into the mouth by the salivary glands and mucous glands of the mouth; moistens the mouth and starts the digestion of starches


a duct through which saliva passes from the salivary gland into the mouth


oewn-drool-n oewn-dribble-n oewn-drivel-n oewn-slobber-n


saliva colored brown by tobacco (snuff or chewing tobacco)


the oily secretion of the sebaceous glands; with perspiration it moistens and protects the skin


a white secretion of the sebaceous glands of the foreskin


substance discharged from the vagina (cellular debris and mucus and blood) that gradually decreases in amount during the weeks following childbirth


oewn-pus-n oewn-purulence-n oewn-suppuration-n oewn-ichor-n oewn-sanies-n oewn-festering-n


a thin morbid discharge as from a wound or especially chronic gonorrhea


discharge of white mucous material from the vagina; often an indication of infection


a blood vessel in a fetus that bypasses pulmonary circulation by connecting the pulmonary artery directly to the ascending aorta; normally closes at birth


a ductus arteriosus that failed to close at birth; may require surgical correction


any small blood vessel ramifying on the outside of a major artery or vein


a blood vessel that carries blood from the capillaries toward the heart

all veins except the pulmonary vein carry unaerated blood


(zoology) the system of venous blood vessels in an animal


a vein that is permanently dilated; most common in the legs


vein of the head of the penis; tributary of the internal pudendal vein that drains the perineum


superficial dorsal veins of the penis; paired tributaries of the external pudendal veins on each side


deep dorsal vein of the penis; tributary of the prostatic plexus


deep vein of the penis; enters the prostatic plexus


either of two large veins that return oxygen-depleted blood to the right atrium of the heart


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


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


deep veins of the clitoris; join the vesical plexus


deep dorsal vein of the clitoris; tributary of the vesical venous plexus


superficial dorsal veins of the clitoris; tributaries of the external pudendal vein on either side


interlobular veins of the kidney; receive blood from the arcuate vein and empty into the renal veins


veins of the kidney; drain the kidney into the renal vein


veins from the labia majora to the external pudendal vein


veins that pass posterior from the labia majora to the internal pudendal vein


a bulging body part (as the belly of a muscle)


`in venter' is legal terminology for `conceived but not yet born'


oewn-ventral_root-n oewn-ventral_horn-n oewn-anterior_root-n oewn-anterior_horn-n

one of the two roots of a spinal nerve that passes ventrally from the spinal cord and that consists of motor fibers


oewn-dorsal_root-n oewn-dorsal_horn-n oewn-posterior_root-n oewn-posterior_horn-n

one of two roots of a spinal nerve that passes dorsally from the spinal cord and that consists of sensory fibers


a vein that goes through the foramina of the cervical vertebrae and forms a plexus around the vertebral artery; empties into the brachiocephalic vein


veins that drain the vesical plexus and join the internal iliac veins


veins that drain the saccule and utricle


a vein formed by branches from the back surface of the eye and the ciliary body; empties into the ophthalmic veins


any of the minute blood vessels connecting arterioles with venules


a minute vein continuous with a capillary


a pliable sheet of tissue that covers or lines or connects the organs or cells of animals or plants


the innermost light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve


a nerve cell whose body is outside the central nervous system

damage to ganglion cells in the retina may play a role in the development of glaucoma


an extensible membrane enclosing the contractile substance of a muscle fiber


a transparent membrane that lines the abdominal cavity in mammals and covers most of the viscera


the interior of the peritoneum; a potential space between layers of the peritoneum


an isolated part of the peritoneal cavity that is dorsal to the stomach


the membrane that lines the cavities of the heart and forms part of the heart valves


a serous membrane with two layers that surrounds the heart


the innermost of the two layers of the pericardium


the tough outermost layer of the pericardium that is attached to the diaphragm and the sternum


the space between the layers of the pericardium that contains fluid that lubricates the membrane surfaces and allows easy heart movement


a double layer of peritoneum that attaches to the back wall of the abdominal cavity and supports the small intestines


mesentery that holds the lower colon to the dorsal abdominal wall


a fold of peritoneum supporting the viscera


part of the peritoneum attached to the stomach and to the colon and covering the intestines


a part of the peritoneum attached to the stomach and liver and supporting the hepatic vessels


the connective tissue beneath mucous membrane


any of the lymph glands of the armpit; fights infections in the neck and chest and arm regions


any of several lymph nodes in the walls of the intestines near the junction of the ileum and colon


any of the cells of a plant or animal except the reproductive cells; a cell that does not participate in the production of gametes

somatic cells are produced from preexisting cells


a cell that is part of a malignant tumor


a mass of undifferentiated cells from which an organ or body part develops


a biological unit consisting of a nucleus and the body of cytoplasm with which it interacts


the nucleus of the ovum or sperm after fertilization but before they fuse to form the nucleus of the zygote


(genetics) the diploid cell resulting from the union of a haploid spermatozoon and ovum (including the organism that develops from that cell)


(genetics) an organism having two different alleles of a particular gene and so giving rise to varying offspring


(genetics) an organism having two identical alleles of a particular gene and so breeding true for the particular characteristic


the substance of a living cell (including cytoplasm and nucleus)


the protoplasm of a cell excluding the nucleus; is full of proteins that control cell metabolism


the intact cytoplasmic content of a cell


a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence


the aqueous part of the cytoplasm within which various particles and organelles are suspended


the outer granule-free layer of cytoplasm


the inner portion of the cytoplasm of a cell


the clear nongranular portion of the cytoplasm of a cell


an organelle found in the cytoplasm of most cells (especially in leukocytes and liver and kidney cells)


a tiny granule in the cytoplasm that is where protein synthesis takes place under the direction of mRNA


oewn-Golgi_body-n oewn-Golgi_apparatus-n oewn-Golgi_complex-n oewn-dictyosome-n

a netlike structure in the cytoplasm of animal cells (especially in those cells that produce secretions)


the protoplasm that constitutes the nucleus of a cell


a part of the cell containing DNA and RNA and responsible for growth and reproduction


a small round body of protein in a cell nucleus; such organelles contain RNA and are involved in protein synthesis


oewn-nucleolus_organizer-n oewn-nucleolus_organiser-n oewn-nucleolar_organizer-n oewn-nucleolar_organiser-n

the particular part of a chromosome that is associated with a nucleolus after nuclear division


the protoplasm of the germ cells that contains chromosomes and genes


the presence or absence of sex chromatin in cells obtained by amniocentesis makes it possible to determine the sex of a fetus


the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins; during mitotic division it condenses into chromosomes


the part of a cell nucleus that is relatively uncolored by stains or dyes


an obsolete term for the network of viscous material in the cell nucleus on which the chromatin granules were thought to be suspended


(genetics) a segment of DNA that is involved in producing a polypeptide chain; it can include regions preceding and following the coding DNA as well as introns between the exons; it is considered a unit of heredity


gene that produces the same phenotype in the organism whether or not its allele identical


(genetics) either of a pair (or series) of alternative forms of a gene that can occupy the same locus on a particular chromosome and that control the same character


an allele that produces the same phenotype whether its paired allele is identical or different


an allele that produces its characteristic phenotype only when its paired allele is identical


a specific gene that produces a recognizable trait and can be used in family or population studies


one the genes that are involved in embryologic development


one of various similar homeotic genes that are involved in bodily segmentation during embryonic development


any gene that has an effect that causes the death of the organism at any stage of life


any pair of genes that tend to be transmitted together

the genes of Drosophila fall into four linkage groups


a gene that modifies the effect produced by another gene


a gene that has changed so that the normal transmission and expression of a trait is affected


(genetics) a combination of alleles (for different genes) that are located closely together on the same chromosome and that tend to be inherited together


the gene that is mutated in cystic fibrosis


genes that are not competitors at the same locus


a gene that activates the production of messenger RNA by adjacent structural genes


a segment of DNA containing adjacent genes including structural genes and an operator gene and a regulatory gene


a gene that disposes normal cells to change into cancerous tumor cells


a gene that by itself has little effect on the phenotype but which can act together with others to produce observable variations


a normal gene that has the potential to become an oncogene


gene that produces its characteristic phenotype only when its allele is identical


a gene that produces a repressor substance that inhibits an operator gene


gene that prevents a nonallele from being transcribed


a gene that controls the production of a specific protein or peptide


oewn-suppressor-n oewn-suppresser-n oewn-suppressor_gene-n oewn-suppresser_gene-n

a gene that suppresses the phenotypic expression of another gene (especially of a mutant gene)


an exogenous gene introduced into the genome of another organism


a suppressor gene that blocks unscheduled cell division


a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order

humans have 22 chromosome pairs plus two sex chromosomes


the sex chromosome that is present in both sexes: singly in males and doubly in females

human females normally have two X chromosomes


(genetics) normal complement of sex chromosomes in a female


(genetics) abnormal complement of three X chromosomes in a female


(genetics) abnormal complement of sex hormones in a male resulting in Klinefelter's syndrome


(genetics) normal complement of sex hormones in a male


(genetics) abnormal complement of sex hormones in a male who has two Y chromosomes


the sex chromosome that is carried by men

human males normally have one X chromosome and one Y chromosome


(genetics) a chromosome that determines the sex of an individual

mammals normally have two sex chromosomes


any chromosome that is not a sex chromosome; appear in pairs in body cells but as single chromosomes in spermatozoa


one of two identical strands into which a chromosome splits during mitosis


a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape


a chromosome with the centromere near one end so that one chromosomal arm is short and one is long


the appearance of the chromosomal makeup of a somatic cell in an individual or species (including the number and arrangement and size and structure of the chromosomes)


a chromosome having two equal arms because the centromere is in median position


a chromosome like a straight rod with the centromere in terminal position


an organelle containing enzymes responsible for producing energy


a large mitochondrion in a striated muscle fiber


a specialized part of a cell; analogous to an organ

the first organelle to be identified was the nucleus


star-shaped structure formed in the cytoplasm of a cell having fibers like rays that surround the centrosome during mitosis


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


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

the ribosome is the site of protein synthesis


small region of cytoplasm adjacent to the nucleus; contains the centrioles and serves to organize the microtubules


the cytoplasm of a striated muscle fiber


a tiny cavity filled with fluid in the cytoplasm of a cell


the whitish fibrous membrane (albuginea) that with the cornea forms the outer covering and protection of the eyeball


a membrane (as a cell membrane) that allows some molecules to pass through but not others


a nucleated cell in bone marrow from which red blood cells develop


a cell from which connective tissue develops


an immature leukocyte normally found in bone marrow


a precursor of leukocytes that normally occurs only in bone marrow


an erythroblast having granules of ferritin


a large bone marrow cell; regarded as the source of blood platelets


cell that functions in the breakdown and resorption of bone tissue


either of two types of cells (erythrocytes and leukocytes) and sometimes including platelets


a cell without a nucleus (as an erythrocyte)


abnormally large red blood cell (associated with pernicious anemia)


abnormally large red blood cell present in pernicious anemia and folic acid deficiency


oewn-leukocyte-n oewn-leucocyte-n oewn-white_blood_cell-n oewn-white_cell-n oewn-white_blood_corpuscle-n oewn-white_corpuscle-n oewn-WBC-n

blood cells that engulf and digest bacteria and fungi; an important part of the body's defense system


a preparation of blood cells separated from the liquid plasma

packed cells are given to severely anemic patients in order to avoid overloading the circulatory system with too much fluid


a macrophage that is found in connective tissue


a large phagocyte; some are fixed and other circulate in the blood stream


a cell that engulfs and digests debris and invading microorganisms


a phagocyte that does not circulate in the blood but is fixed in the liver or spleen or bone marrow etc.


a phagocyte that circulates in the blood


an agranulocytic leukocyte that normally makes up a quarter of the white blood cell count but increases in the presence of infection


a lymphocyte derived from bone marrow that provides humoral immunity; it recognizes free antigen molecules in solution and matures into plasma cells that secrete immunoglobulin (antibodies) that inactivate the antigens


a small lymphocyte developed in the thymus; it orchestrates the immune system's response to infected or malignant cells


oewn-helper_T_cell-n oewn-helper_cell-n oewn-CD4_T_cell-n oewn-CD4_cell-n

T cell with CD4 receptor that recognizes antigens on the surface of a virus-infected cell and secretes lymphokines that stimulate B cells and killer T cells; helper T cells are infected and killed by the AIDS virus


oewn-killer_T_cell-n oewn-killer_cell-n oewn-cytotoxic_T_cell-n oewn-CD8_T_cell-n oewn-CD8_cell-n

T cell with CD8 receptor that recognizes antigens on the surface of a virus-infected cell and binds to the infected cell and kill it


a cell that develops from a B lymphocyte in reaction to a specific antigen; found in bone marrow and sometimes in the blood


a leukocyte that has granules in its cytoplasm


a type of granular leukocyte that functions in the ingestion of bacteria


a large immature monocyte normally found in bone marrow


a leukocyte with basophilic granules easily stained by basic stains


the chief phagocytic leukocyte; stains with either basic or acid dyes


a neutrophil that ingests small things (as bacteria)


a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus


an abnormal red blood cell that has thorny projections of protoplasm


an abnormally small red blood cell (less than 5 microns in diameter)


an immature red blood cell containing a network of filaments or granules


an abnormal red blood cell that has a crescent shape and an abnormal form of hemoglobin


an abnormal red blood cell containing granules of iron not bound in hemoglobin


an abnormal red blood cell with the appearance of a dark ring surrounding a dark center; associated with anemia


area consisting of a small depression in the retina containing cones and where vision is most acute


area of the retina immediately surrounding the fovea


oewn-macula-n oewn-macula_lutea-n oewn-macular_area-n oewn-yellow_spot-n

a small yellowish central area of the retina that is rich in cones and that mediates clear detailed vision


one of the cells of the retina that is sensitive to light


the point where the optic nerve enters the retina; not sensitive to light


a visual receptor cell in the retina that is sensitive to bright light and to color


a visual receptor cell that is sensitive to dim light


a spermatozoon or an ovum; a cell responsible for transmitting DNA to the next generation


a mature sexual reproductive cell having a single set of unpaired chromosomes


either of a pair of unlike gametes especially those unlike in size


either of a pair of conjugating gametes of the same size and structure


oewn-sperm-n oewn-sperm_cell-n oewn-spermatozoon-n oewn-spermatozoan-n

the male reproductive cell; the male gamete

a sperm is mostly a nucleus surrounded by little other cellular material


a process at the anterior end of a sperm cell that produces enzymes to facilitate penetration of the egg


the female reproductive cell; the female gamete


mature ovum after penetration by sperm but before the formation of a zygote


an immature animal or plant cell that develops into a gamete by meiosis


a female gametocyte that develops into an ovum after two meiotic divisions


a small cell containing little cytoplasm that is produced along with the oocyte and later discarded


a swelling on the epididymis or the testis; usually contains spermatozoa


a male gametocyte that develops into four spermatids


an immature gamete produced by a spermatocyte; develops into a spermatozoon


an elongated contractile cell that forms the muscles of the body


a cell in the testes that secretes the hormone testosterone


elongated cells found in the seminiferous tubules of the testis; apparently they nourish the spermatids


an elongated contractile cell in striated muscle tissue


one of many contractile filaments that make up a striated muscle fiber


one of the segments into which a myofibril is divided


muscle tissue that does not appear striated under the microscope; has the form of thin layers or sheets


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)


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


a widely distributed system consisting of all the cells able to ingest bacteria or colloidal particles etc, except for certain white blood cells


a widely distributed system of free and fixed macrophages derived from bone marrow


the system of muscles and tendons and ligaments and bones and joints and associated tissues that move the body and maintain its form


the sensory and control apparatus consisting of a network of nerve cells


a structure that is part of the nervous system


oewn-center-n oewn-centre-n oewn-nerve_center-n oewn-nerve_centre-n

a cluster of nerve cells governing a specific bodily process

in most people the speech center is in the left hemisphere


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


a nerve fiber encased in a sheath of myelin


small gaps in the myelin sheath of medullated axons


a layer of myelin encasing (and insulating) the axons of medullated nerve fibers


thin membranous sheath around a nerve fiber


any cell that covers the nerve fibers in the peripheral nervous system and forms the myelin sheath


a nerve fiber that terminates on a muscle or gland and stimulates contraction or secretion


a specialized structure at the peripheral end of some motor or sensory nerve fibers


a cell that is specialized to conduct nerve impulses


a neuron in the cerebral cortex with short dendrites and with either a long axon or a short axon that ramifies in the grey matter


a large densely branching neuron that is the characteristic cell of the cerebellar cortex


the flattened end of a motor neuron that transmits neural impulses to a muscle


sensory end organ that responds to changes in osmotic pressure


oewn-motor_neuron-n oewn-efferent_neuron-n oewn-motor_nerve_fiber-n oewn-motoneuron-n

a neuron conducting impulses outwards from the brain or spinal cord


a neuron conducting impulses inwards to the brain or spinal cord


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


tissue consisting of large stellate neuroglial cells


star-shaped cells with long processes; found in the white matter of the brain and spinal cord


a kind of astrocyte found in the grey matter


neuroglial tissue of mesodermal origin that can become phagocytic


a cell of the microglia that may become phagocytic and collect waste products of nerve tissue


tissue consisting of glial cells with sheetlike processes that form the myelin sheath of nerve fibers


long nerve fiber that conducts away from the cell body of the neuron


the terminal structure of an axon that does not end at a synapse


microscopic sensory nerve endings in the skin that are not connected to any specific sensory receptor


a specialized bulblike nerve ending located in the subcutaneous tissue of the skin; occurs abundantly in the skin of palms and soles and joints and genitals


special nerve endings in the muscles and tendons and other organs that respond to stimuli regarding the position and movement of the body


short fiber that conducts toward the cell body of the neuron


a hybrid cell resulting from the fusion of a lymphocyte and a tumor cell; used to culture a specific monoclonal antibody


a natural prolongation or projection from a part of an organism either animal or plant


an outgrowth on a plant or animal such as a fowl's wattle or a protuberance near the hilum of certain seeds


a fleshy wrinkled and often brightly colored fold of skin hanging from the neck or throat of certain birds (chickens and turkeys) or lizards


a round bump on a bone where it forms a joint with another bone


the condyle of the ramus of the mandible that articulates with the skull


a sharp triangular process projecting from a bone


the coronoid process that provides an attachment for the temporal muscle


a condyle on the outer side of the lower extremity of the femur


a condyle on the inner side of the lower extremity of the femur


a projection on a bone above a condyle serving for the attachment of muscles and ligaments


epicondyle near the lateral condyle of the femur


thin projections forming a fringe (especially around the ovarian end of the Fallopian tube)


(anatomy) a natural outgrowth or projection on an organ or body part such as the process of a vertebra


small pointed structure serving as a skeletal element in various marine and freshwater invertebrates e.g. sponges and corals


a small projection of tissue at the base of a hair or tooth or feather


a small nipple-shaped protuberance concerned with taste, touch, or smell


the junction between two neurons (axon-to-dendrite) or between a neuron and a muscle

nerve impulses cross a synapse through the action of neurotransmitters


the junction between a nerve fiber and the muscle it supplies


any bundle of nerve fibers running to various organs and tissues of the body


a nerve that conveys impulses toward or to muscles or glands


a nerve fiber that carries impulses toward the muscles or glands


a nerve that passes impulses from receptors toward or to the central nervous system


a nerve fiber that carries impulses toward the central nervous system


a bundle of sensory nerve fibers going to the thalamus


oewn-fiber_bundle-n oewn-fibre_bundle-n oewn-fascicle-n oewn-fasciculus-n

a bundle of fibers (especially nerve fibers)


oewn-nerve_pathway-n oewn-tract-n oewn-nerve_tract-n oewn-pathway-n

a bundle of myelinated nerve fibers following a path through the brain


a bundle of nerve fibers passing from one side to the other of the brain or spinal cord


any of the 12 paired nerves that originate in the brain stem


any nerve whose activity tends to reduce the activity or tone of the body part it serves


a bundle of myelinated neurons joining different parts of the brain


the cerebral hemisphere to the left of the corpus callosum that controls the right half of the body


oewn-pyriform_area-n oewn-piriform_area-n oewn-pyriform_lobe-n oewn-piriform_lobe-n

pear-shaped neural structure on either side of the brain in the rhinencephalon


the cerebral hemisphere to the right of the corpus callosum that controls the left half of the body


a center in the cerebral hemispheres that governs the sense of smell in lower animals; in humans it seems to mediate complex emotional behavior


a collective term for numerous olfactory filaments in the nasal mucosa


one of two enlargements at the terminus of the olfactory nerve at the base of the brain just above the nasal cavities


oewn-optic_nerve-n oewn-nervus_opticus-n oewn-second_cranial_nerve-n oewn-optic_tract-n

the cranial nerve that serves the retina


oewn-oculomotor-n oewn-oculomotor_nerve-n oewn-nervus_oculomotorius-n oewn-third_cranial_nerve-n


oewn-trochlear-n oewn-trochlear_nerve-n oewn-trochlearis-n oewn-fourth_cranial_nerve-n

either of the two cranial nerves on either side that control the superior oblique muscles of the eyes


oewn-trigeminal-n oewn-trigeminal_nerve-n oewn-trigeminus-n oewn-nervus_trigeminus-n oewn-fifth_cranial_nerve-n

the main sensory nerve of the face and motor nerve for the muscles of mastication


oewn-abducent-n oewn-abducent_nerve-n oewn-abducens-n oewn-abducens_nerve-n oewn-nervus_abducens-n oewn-sixth_cranial_nerve-n

a small motor nerve supplying the lateral rectus muscle of the eye