Short glossary of biology

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  • ACE - of the highest quality
  • AChE - a dull persistent (usually moderately intense) pain
  • ADD - a condition (mostly in boys) characterized by behavioral and learning disorders
  • ADH - 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
  • ADHD - a condition (mostly in boys) characterized by behavioral and learning disorders
  • APC - a drug combination found in some over-the-counter headache remedies (aspirin and phenacetin and caffeine)
  • APC - a drug combination found in some over-the-counter headache remedies (aspirin and phenacetin and caffeine)
  • ATP - a nucleotide derived from adenosine that occurs in muscle tissue; the major source of energy for cellular reactions
  • ATP - a nucleotide derived from adenosine that occurs in muscle tissue; the major source of energy for cellular reactions
  • AV - the eleventh month of the civil year; the fifth month of the ecclesiastical year in the Jewish calendar (in July and August)
  • AV - the eleventh month of the civil year; the fifth month of the ecclesiastical year in the Jewish calendar (in July and August)
  • AV - the eleventh month of the civil year; the fifth month of the ecclesiastical year in the Jewish calendar (in July and August)
  • Actin - one of the proteins into which actomyosin can be split; can exist in either a globular or a fibrous form
  • Alzheimer's disease - a progressive form of presenile dementia that is similar to senile dementia except that it usually starts in the 40s or 50s; first symptoms are impaired memory which is followed by impaired thought and speech and finally complete helplessness
  • B lymphocyte - 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
  • Bartholin's gland - either of the two posterior vestibular glands that secrete a lubricating mucus; homologous to Cowper's gland in the male
  • Boyle's law - the pressure of an ideal gas at constant temperature varies inversely with the volume
  • CA - a state in the western United States on the Pacific; the 3rd largest state; known for earthquakes
  • CNS - the portion of the vertebrate nervous system consisting of the brain and spinal cord
  • CNS - the portion of the vertebrate nervous system consisting of the brain and spinal cord
  • CO - a state in west central United States in the Rocky Mountains
  • CPR - an emergency procedure consisting of external cardiac massage and artificial respiration; the first treatment for a person who has collapsed and has no pulse and has stopped breathing; attempts to restore circulation of the blood and prevent death or brain damage due to lack of oxygen
  • CT - a method of examining body organs by scanning them with X rays and using a computer to construct a series of cross-sectional scans along a single axis
  • CVA - a sudden loss of consciousness resulting when the rupture or occlusion of a blood vessel leads to oxygen lack in the brain
  • Cowper's gland - either of two glands that discharge a component of seminal fluid into the urethra; homologous to Bartholin's gland in the female
  • DNA - (biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information
  • DNA - (biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information
  • ECG - a graphical recording of the cardiac cycle produced by an electrocardiograph
  • ECG - a graphical recording of the cardiac cycle produced by an electrocardiograph
  • ELISA - an assay that relies on an enzymatic conversion reaction and is used to detect the presence of specific substances (such as enzymes or viruses or antibodies or bacteria)
  • ER - a room in a hospital or clinic staffed and equipped to provide emergency care to persons requiring immediate medical treatment
  • ER - a room in a hospital or clinic staffed and equipped to provide emergency care to persons requiring immediate medical treatment
  • FSH - a gonadotropic hormone that is secreted by the anterior pituitary and stimulates growth of Graafian follicles in female mammals, and activates the cells in male mammals that form sperm
  • Golgi apparatus - a netlike structure in the cytoplasm of animal cells (especially in those cells that produce secretions)
  • HCG - hormone produced early in pregnancy by the placenta; detection in the urine and serum is the basis for one kind of pregnancy test
  • HR - a period of time equal to 1/24th of a day
  • Haversian canal - any of the many tiny canals that contain blood vessels and connective tissue and that form a network in bone
  • Henry's law - (chemistry) law formulated by the English chemist William Henry; the amount of a gas that will be absorbed by water increases as the gas pressure increases
  • I - the 9th letter of the Roman alphabet
  • I - the 9th letter of the Roman alphabet
  • LH - a gonadotropic hormone that is secreted by the anterior pituitary; stimulates ovulation in female mammals and stimulates androgen release in male mammals
  • Leydig cell - a cell in the testes that secretes the hormone testosterone
  • MALT - a cereal grain that is kiln-dried after having been germinated by soaking in water; used especially in brewing and distilling
  • MAP - a diagrammatic representation of the earth's surface (or part of it)
  • MRI - the use of nuclear magnetic resonance of protons to produce proton density images
  • MT - the use of computers to translate from one language to another
  • Mu - the 12th letter of the Greek alphabet
  • NE - a midwestern state on the Great Plains
  • PCT - a proportion multiplied by 100
  • PCT - a proportion multiplied by 100
  • PET - preferred above all others and treated with partiality
  • Parkinson's disease - a degenerative disorder of the central nervous system characterized by tremor and impaired muscular coordination
  • RBC - a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus
  • RNA - (biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes; it transmits genetic information from DNA to the cytoplasm and controls certain chemical processes in the cell
  • RNA - (biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes; it transmits genetic information from DNA to the cytoplasm and controls certain chemical processes in the cell
  • Ru - a rare polyvalent metallic element of the platinum group; it is found associated with platinum
  • SA - Nazi militia created by Hitler in 1921 that helped him to power but was eclipsed by the SS after 1943
  • SA - Nazi militia created by Hitler in 1921 that helped him to power but was eclipsed by the SS after 1943
  • Schwann cell - any cell that covers the nerve fibers in the peripheral nervous system and forms the myelin sheath
  • Sertoli cell - elongated cells found in the seminiferous tubules of the testis; apparently they nourish the spermatids
  • T lymphocyte - a small lymphocyte developed in the thymus; it orchestrates the immune system's response to infected or malignant cells
  • TC - a permanent council of the United Nations that commissions a country (or countries) to undertake the administration of a territory
  • TH - a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands
  • TIA - brief episode in which the brain gets insufficient blood supply; symptoms depend on the site of the blockage
  • TLC - considerate and solicitous care
  • Viagra - virility drug (trade name Viagra) used to treat erectile dysfunction in men
  • WBC - blood cells that engulf and digest bacteria and fungi; an important part of the body's defense system
  • acclimatization - adaptation to a new climate (a new temperature or altitude or environment)
  • acetylcholine - a neurotransmitter that is a derivative of choline; released at the ends of nerve fibers in the somatic and parasympathetic nervous systems
  • acid - having the characteristics of an acid
  • action potential - the local voltage change across the cell wall as a nerve impulse is transmitted
  • active immunity - a form of acquired immunity in which the body produces its own antibodies against disease-causing antigens
  • active site - the part of an enzyme or antibody where the chemical reaction occurs
  • active transport - transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient; requires an expenditure of energy
  • adenosine triphosphate - a nucleotide derived from adenosine that occurs in muscle tissue; the major source of energy for cellular reactions
  • adenosine triphosphate - a nucleotide derived from adenosine that occurs in muscle tissue; the major source of energy for cellular reactions
  • adhesion - a fibrous band of scar tissue that binds together normally separate anatomical structures
  • adrenal cortex - the cortex of the adrenal gland; secretes corticosterone and sex hormones
  • adrenal gland - either of a pair of complex endocrine glands situated near the kidney
  • agglutination - the building of words from component morphemes that retain their form and meaning in the process of combining
  • ala - a wing of an insect
  • albumin - a simple water-soluble protein found in many animal tissues and liquids
  • aldosterone - a corticosteroid hormone that is secreted by the cortex of the adrenal gland; regulates salt (sodium and potassium) and water balance
  • allergy - hypersensitivity reaction to a particular allergen; symptoms can vary greatly in intensity
  • alveolus - a tiny sac for holding air in the lungs; formed by the terminal dilation of tiny air passageways
  • amino acid - organic compounds containing an amino group and a carboxylic acid group
  • ampulla - a flask that has two handles; used by Romans for wines or oils
  • amygdala - an almond-shaped neural structure in the anterior part of the temporal lobe of the cerebrum; intimately connected with the hypothalamus and the hippocampus and the cingulate gyrus; as part of the limbic system it plays an important role in motivation and emotional behavior
  • amylase - any of a group of proteins found in saliva and pancreatic juice and parts of plants; help convert starch to sugar
  • anabolic - characterized by or promoting constructive metabolism
  • anabolism - the synthesis in living organisms of more complex substances (e.g., living tissue) from simpler ones together with the storage of energy
  • anaphase - the stage of meiosis or mitosis when chromosomes move toward opposite ends of the nuclear spindle
  • anaphylactic shock - a severe and rapid and sometimes fatal hypersensitivity reaction to a substance (especially a vaccine or penicillin or shellfish or insect venom) to which the organism has become sensitized by previous exposure
  • anastomosis - a natural or surgical joining of parts or branches of tubular structures so as to make or become continuous
  • anemia - genus of terrestrial or lithophytic ferns having pinnatifid fronds; chiefly of tropical America
  • angiotensin I - a physiologically inactive form of angiotensin that is the precursor to angiotensin II
  • anterior cerebral artery - one of two branches of the internal carotid artery; divides into two branches that serve (1) the thalamus and (2) parts of the frontal and parietal cortex
  • anticoagulant - medicine that prevents or retards the clotting of blood
  • antidiuretic hormone - 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
  • antigen - any substance (as a toxin or enzyme) that stimulates an immune response in the body (especially the production of antibodies)
  • antrum - a natural cavity or hollow in a bone
  • anus - excretory opening at the end of the alimentary canal
  • anvil - a heavy block of iron or steel on which hot metals are shaped by hammering
  • aorta - the large trunk artery that carries blood from the left ventricle of the heart to branch arteries
  • aortic arch - the part of the aorta that arches and turns downward
  • aortic valve - a semilunar valve between the left ventricle and the aorta; prevents blood from flowing from the aorta back into the heart
  • apex - the point on the celestial sphere toward which the sun and solar system appear to be moving relative to the fixed stars
  • applied science - the discipline dealing with the art or science of applying scientific knowledge to practical problems
  • areola - small circular area such as that around the human nipple or an inflamed area around a pimple or insect bite
  • arteriole - one of the small thin-walled arteries that end in capillaries
  • articulation - the act of joining things in such a way that motion is possible
  • ascending aorta - the ascending part of the aorta as it emerges from the left ventricle
  • asthma - respiratory disorder characterized by wheezing; usually of allergic origin
  • astrocyte - comparatively large neuroglial cell
  • atom - (nontechnical usage) a tiny piece of anything
  • atomic number - the order of an element in Mendeleyev's table of the elements; equal to the number of protons in the nucleus or electrons in the neutral state of an atom of an element
  • atrioventricular - relating to or affecting the atria and ventricles of the heart
  • atrioventricular - relating to or affecting the atria and ventricles of the heart
  • atrioventricular bundle - a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract
  • atrioventricular node - a node of specialized heart muscle located in the septal wall of the right atrium; receives impulses from the sinoatrial node and transmits them to atrioventricular bundle
  • atrioventricular valve - either of two heart valves through which blood flows from the atria to the ventricles; prevents return of blood to the atrium
  • atrium - the central area in a building; open to the sky
  • audition - a test of the suitability of a performer
  • auricle - the externally visible cartilaginous structure of the external ear
  • autism - (psychiatry) an abnormal absorption with the self; marked by communication disorders and short attention span and inability to treat others as people
  • autoantibody - an antibody acting against tissues of the organism that produces it
  • autoimmunity - production of antibodies against the tissues of your own body; produces autoimmune disease or hypersensitivity reactions
  • autonomic nervous system - the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands
  • autoregulation - (physiology) processes that maintain a generally constant physiological state in a cell or organism
  • avidity - a positive feeling of wanting to push ahead with something
  • axillary artery - 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
  • axillary vein - a continuation of the basilic vein and brachial vein that becomes the subclavian vein
  • axon - long nerve fiber that conducts away from the cell body of the neuron
  • azygos vein - one of a system of veins that drain the thoracic and abdominal walls; arises as a continuation of the right ascending lumbar vein and terminates in the superior vena cava
  • bacteria - (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered plants
  • base - debased; not genuine
  • basilar artery - an unpaired artery; supplies the pons and cerebellum and the back part of the cerebrum and the inner ear
  • basilic vein - a vein that drains the back of the hand and forearm and empties into the axillary vein
  • basophil - a leukocyte with basophilic granules easily stained by basic stains
  • biodiversity - the diversity of plant and animal life in a particular habitat (or in the world as a whole)
  • biology - the science that studies living organisms
  • biosphere - the regions of the surface and atmosphere of the Earth (or other planet) where living organisms exist
  • biotechnology - the branch of engineering science in which biological science is used to study the relation between workers and their environments
  • bitter - proceeding from or exhibiting great hostility or animosity
  • bladder - a bag that fills with air
  • blood - temperament or disposition
  • blood - temperament or disposition
  • blood clotting - a process in which liquid blood is changed into a semisolid mass (a blood clot)
  • blood plasma - plasma that separates from blood in coagulation
  • blood pressure - the pressure of the circulating blood against the walls of the blood vessels; results from the systole of the left ventricle of the heart; sometimes measured for a quick evaluation of a person's health
  • blood typing - determining a person's blood type by serological methods
  • bolus - a large pill; used especially in veterinary medicine
  • bone - consisting of or made up of bone
  • brachial artery - the main artery of the upper arm; a continuation of the axillary artery; bifurcates into the radial and ulnar arteries at the elbow
  • brachial vein - two veins in either arm that accompany the brachial artery and empty into the axillary vein
  • brain - that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord
  • brainstem - the part of the brain continuous with the spinal cord and comprising the medulla oblongata and pons and midbrain and parts of the hypothalamus
  • bridge - any of various card games based on whist for four players
  • bronchial vein - veins serving the bronchi; empty into the azygos vein
  • bronchiole - any of the smallest bronchial ducts; ending in alveoli
  • bulbourethral gland - either of two glands that discharge a component of seminal fluid into the urethra; homologous to Bartholin's gland in the female
  • bundle of His - a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract
  • calyx - (botany) the whorl of sepals of a flower collectively forming the outer floral envelope or layer of the perianth enclosing and supporting the developing bud; usually green
  • canaliculus - a small canal or duct as in some bones and parts of plants
  • cancer - type genus of the family Cancridae
  • candela - the basic unit of luminous intensity adopted under the Systeme International d'Unites; equal to 1/60 of the luminous intensity per square centimeter of a black body radiating at the temperature of 2,046 degrees Kelvin
  • capacitance - an electrical phenomenon whereby an electric charge is stored
  • capillary - long and slender with a very small internal diameter
  • capillary bed - a layer of tissue densely packed with capillaries
  • carbohydrate - an essential structural component of living cells and source of energy for animals; includes simple sugars with small molecules as well as macromolecular substances; are classified according to the number of monosaccharide groups they contain
  • carbon - a copy made with carbon paper
  • cardiac cycle - the complete cycle of events in the heart from the beginning of one heart beat to the beginning of the next; an electrical impulse conducted through the heart muscle that constricts the atria which is followed by constriction of the ventricles
  • cardiac muscle - the muscle tissue of the heart; adapted to continued rhythmic contraction
  • cardiac output - the amount of blood pumped out by the ventricles in a given period of time
  • cardiac tamponade - mechanical compression of the heart resulting from large amounts of fluid collecting in the pericardial space and limiting the heart's normal range of motion
  • cardiopulmonary resuscitation - an emergency procedure consisting of external cardiac massage and artificial respiration; the first treatment for a person who has collapsed and has no pulse and has stopped breathing; attempts to restore circulation of the blood and prevent death or brain damage due to lack of oxygen
  • cartilage - tough elastic tissue; mostly converted to bone in adults
  • catabolic - characterized by destructive metabolism
  • catabolism - breakdown in living organisms of more complex substances into simpler ones together with release of energy
  • caudal - situated in or directed toward the part of the body from which the tail arises
  • cavernous sinus - either of a pair of large venous sinuses in the cranial cavity
  • celiac trunk - 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
  • cell - (biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals
  • cell - (biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals
  • cellulose - a polysaccharide that is the chief constituent of all plant tissues and fibers
  • centriole - one of a pair of small cylindrical cell organelles near the nucleus in animal cells; composed of nine triplet microtubules and form the asters during mitosis
  • cephalic vein - a large vein of the arm that empties into the axillary vein
  • cerebellum - a major division of the vertebrate brain; situated above the medulla oblongata and beneath the cerebrum in humans
  • cerebral cortex - the layer of unmyelinated neurons (the grey matter) forming the cortex of the cerebrum
  • cerebrovascular accident - a sudden loss of consciousness resulting when the rupture or occlusion of a blood vessel leads to oxygen lack in the brain
  • checkpoint - a place (as at a frontier) where travellers are stopped for inspection and clearance
  • chemistry - the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions
  • chiasma - an intersection or crossing of two tracts in the form of the letter X
  • chitin - a tough semitransparent horny substance; the principal component of the exoskeletons of arthropods and the cell walls of certain fungi
  • chloroplast - plastid containing chlorophyll and other pigments; in plants that carry out photosynthesis
  • choroid plexus - a vascular plexus of the cerebral ventricles that regulate intraventricular pressure
  • chyme - a semiliquid mass of partially digested food that passes from the stomach through the pyloric sphincter into the duodenum
  • cilium - a hairlike projection from the surface of a cell; provides locomotion in free-swimming unicellular organisms
  • circadian - of or relating to biological processes occurring at 24-hour intervals
  • clitoris - a female sexual organ homologous to the penis
  • clotting factor - any of the factors in the blood whose actions are essential for blood coagulation
  • coagulation - the process of forming semisolid lumps in a liquid
  • 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
  • codon - a specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid
  • cohesion - (physics) the intermolecular force that holds together the molecules in a solid or liquid
  • colon - the part of the large intestine between the cecum and the rectum; it extracts moisture from food residues before they are excreted
  • common carotid artery - runs upward in the neck and divides into the external and internal carotid arteries
  • 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
  • community - (ecology) a group of interdependent organisms inhabiting the same region and interacting with each other
  • computed tomography - a method of examining body organs by scanning them with X rays and using a computer to construct a series of cross-sectional scans along a single axis
  • cone - any cone-shaped artifact
  • control - the activity of managing or exerting control over something
  • control center - the operational center for a group of related activities
  • cornea - transparent anterior portion of the outer covering of the eye; it covers the lens and iris and is continuous with the sclera
  • coronary artery - the artery that branches from the aorta to supply blood to the heart
  • coronary sinus - a short sinus receiving most of the veins of the heart; empties into the right atrium
  • corpus callosum - a broad transverse nerve tract connecting the two cerebral hemispheres
  • corpus luteum - yellow endocrine tissue that forms in a ruptured Graafian follicle following the release of an ovum
  • cortex - the tissue forming the outer layer of an organ or structure in plant or animal
  • covalent bond - a chemical bond that involves sharing a pair of electrons between atoms in a molecule
  • cranial - of or relating to the cranium which encloses the brain
  • cranial nerve - any of the 12 paired nerves that originate in the brain stem
  • crossing over - the interchange of sections between pairing homologous chromosomes during the prophase of meiosis
  • crossover - the appropriation of a new style (especially in popular music) by combining elements of different genres in order to appeal to a wider audience
  • cryptorchidism - failure of one or both testes to move into the scrotum as the male fetus develops
  • cystic artery - a branch of the hepatic artery; supplies the gall bladder and the surface of the liver
  • cytokine - any of various proteins secreted by cells of the immune system that serve to regulate the immune system
  • cytokinesis - organic process consisting of the division of the cytoplasm of a cell following karyokinesis bringing about the separation into two daughter cells
  • cytology - the branch of biology that studies the structure and function of cells
  • cytoplasm - the protoplasm of a cell excluding the nucleus; is full of proteins that control cell metabolism
  • cytoskeleton - a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence
  • cytosol - the aqueous part of the cytoplasm within which various particles and organelles are suspended
  • deep - exhibiting great cunning usually with secrecy
  • dendrite - short fiber that conducts toward the cell body of the neuron
  • deoxyribonucleic acid - (biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information
  • deoxyribonucleic acid - (biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information
  • deoxyribose - a sugar that is a constituent of nucleic acids
  • descending aorta - the descending part of the aorta that branches into the thoracic and abdominal aortae
  • development - act of improving by expanding or enlarging or refining
  • diabetes mellitus - diabetes caused by a relative or absolute deficiency of insulin and characterized by polyuria
  • diapedesis - passage of blood cells (especially white blood cells) through intact capillary walls and into the surrounding tissue
  • diaphysis - the main (mid) section of a long bone
  • diastole - the widening of the chambers of the heart between two contractions when the chambers fill with blood
  • diastolic pressure - the blood pressure (as measured by a sphygmomanometer) after the contraction of the heart while the chambers of the heart refill with blood
  • diploid - of a cell or organism having two sets of chromosomes or twice the haploid number
  • disaccharide - any of a variety of carbohydrates that yield two monosaccharide molecules on complete hydrolysis
  • disease - an impairment of health or a condition of abnormal functioning
  • distal - situated farthest from point of attachment or origin, as of a limb or bone
  • diuretic - any substance that tends to increase the flow of urine
  • diversity - the condition or result of being changed
  • double helix - a pair of parallel helices intertwined about a common axis
  • ductus arteriosus - a blood vessel in a fetus that bypasses pulmonary circulation by connecting the pulmonary artery directly to the ascending aorta; normally closes at birth
  • ductus deferens - a duct that carries spermatozoa from the epididymis to the ejaculatory duct
  • duodenum - the part of the small intestine between the stomach and the jejunum
  • dura mater - the outermost (and toughest) of the 3 meninges
  • ecology - the branch of biology concerned with the relations between organisms and their environment
  • ecosystem - a system formed by the interaction of a community of organisms with their physical environment
  • ectotherm - an animal whose body temperature varies with the temperature of its surroundings; any animal except birds and mammals
  • edema - swelling from excessive accumulation of serous fluid in tissue
  • egg - animal reproductive body consisting of an ovum or embryo together with nutritive and protective envelopes; especially the thin-shelled reproductive body laid by e.g. female birds
  • ejaculation - an abrupt emphatic exclamation expressing emotion
  • ejaculatory duct - a part of the seminal duct formed by the duct from the seminal vesicle and the vas deferens; passes through the prostate gland
  • electrocardiogram - a graphical recording of the cardiac cycle produced by an electrocardiograph
  • electrocardiogram - a graphical recording of the cardiac cycle produced by an electrocardiograph
  • electron - an elementary particle with negative charge
  • electron microscope - a microscope that is similar in purpose to a light microscope but achieves much greater resolving power by using a parallel beam of electrons to illuminate the object instead of a beam of light
  • element - the most favorable environment for a plant or animal
  • elements - violent or severe weather (viewed as caused by the action of the four elements)
  • embolus - an abnormal particle (e.g. an air bubble or part of a clot) circulating in the blood
  • emigration - migration from a place (especially migration from your native country in order to settle in another)
  • endocardium - the membrane that lines the cavities of the heart and forms part of the heart valves
  • endocrine gland - any of the glands of the endocrine system that secrete hormones directly into the bloodstream
  • endocrinologist - physician who specializes in the diagnosis and treatment of conditions affecting the endocrine system
  • endoderm - the inner germ layer that develops into the lining of the digestive and respiratory systems
  • endometrium - (pregnancy) the mucous membrane that lines the uterus; thickens under hormonal control and (if pregnancy does not occur) is shed in menstruation; if pregnancy occurs it is shed along with the placenta at parturition
  • endosteum - vascular membrane that lines the inner surface of long bones
  • endothelium - an epithelium of mesoblastic origin; a thin layer of flattened cells that lines the inside of some body cavities
  • energy - an imaginative lively style (especially style of writing)
  • enzyme - any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions
  • eosinophil - a leukocyte readily stained with eosin
  • epicardium - the innermost of the two layers of the pericardium
  • epididymis - a convoluted tubule in each testis; carries sperm to vas deferens
  • epiglottis - a flap of cartilage that covers the windpipe while swallowing
  • epilepsy - a disorder of the central nervous system characterized by loss of consciousness and convulsions
  • epiphysis - the end of a long bone; initially separated from the main bone by a layer of cartilage that eventually ossifies so the parts become fused
  • epitope - the site on the surface of an antigen molecule to which an antibody attaches itself
  • erectile dysfunction - impotence resulting from a man's inability to have or maintain an erection of his penis
  • erectile tissue - vascular tissue capable of filling with blood and becoming rigid
  • erythroblastosis - a blood disease characterized by the abnormal presence of erythroblasts in the blood
  • erythrocyte - a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus
  • erythropoiesis - the process of producing red blood cells by the stem cells in the bone marrow
  • erythropoietin - a glycoprotein secreted by the kidneys that stimulates the production of red blood cells
  • esophagus - the passage between the pharynx and the stomach
  • estrogen - a general term for female steroid sex hormones that are secreted by the ovary and responsible for typical female sexual characteristics
  • eukaryote - an organism with cells characteristic of all life forms except primitive microorganisms such as bacteria; i.e. an organism with `good' or membrane-bound nuclei in its cells
  • evolution - (biology) the sequence of events involved in the evolutionary development of a species or taxonomic group of organisms
  • exon - sequence of a gene's DNA that transcribes into protein structures
  • expiration - the act of expelling air from the lungs
  • external carotid artery - the branch of the carotid artery that supplies blood to the face and tongue and external parts of the head
  • external respiration - the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation
  • eye - a small hole or loop (as in a needle)
  • fallopian tube - either of a pair of tubes conducting the egg from the ovary to the uterus
  • fat - a chubby body
  • fauces - the passage between the back of the mouth and the pharynx
  • femoral artery - the chief artery of the thigh; a continuation of the external iliac artery
  • femoral vein - a vein that accompanies the femoral artery in the same sheath; a continuation of the popliteal vein; becomes the external iliac vein
  • fenestration - surgical procedure that creates a new fenestra to the cochlea in order to restore hearing lost because of osteosclerosis
  • fermentation - a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol
  • ferritin - a protein containing 20% iron that is found in the intestines and liver and spleen; it is one of the chief forms in which iron is stored in the body
  • fertilization - making fertile as by applying fertilizer or manure
  • fetal circulation - the system of blood vessels and structures through which blood moves in a fetus
  • fetus - an unborn or unhatched vertebrate in the later stages of development showing the main recognizable features of the mature animal
  • flagellum - a lash-like appendage used for locomotion (e.g., in sperm cells and some bacteria and protozoa)
  • flat bone - part of the sirloin next to the wedge bone
  • follicle - any small spherical group of cells containing a cavity
  • food pyramid - (ecology) a hierarchy of food chains with the principal predator at the top; each level preys on the level below
  • fovea - area consisting of a small depression in the retina containing cones and where vision is most acute
  • fracture - the act of cracking something
  • free nerve ending - microscopic sensory nerve endings in the skin that are not connected to any specific sensory receptor
  • frontal lobe - that part of the cerebral cortex in either hemisphere of the brain lying directly behind the forehead
  • gallbladder - a muscular sac attached to the liver that secretes bile and stores it until needed for digestion
  • gamete - a mature sexual reproductive cell having a single set of unpaired chromosomes
  • gene - (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 expression - conversion of the information encoded in a gene first into messenger RNA and then to a protein
  • genetic code - the ordering of nucleotides in DNA molecules that carries the genetic information in living cells
  • genetics - the branch of biology that studies heredity and variation in organisms
  • genome - the ordering of genes in a haploid set of chromosomes of a particular organism; the full DNA sequence of an organism
  • gestation - the conception and development of an idea or plan
  • gestation period - the period during which an embryo develops (about 266 days in humans)
  • glabrous - having no hair or similar growth; smooth
  • glans penis - the conical mass of erectile tissue that forms the head of the penis
  • glia - sustentacular tissue that surrounds and supports neurons in the central nervous system; glial and neural cells together compose the tissue of the central nervous system
  • globin - a colorless protein obtained by removing heme from hemoglobin; the oxygen carrying compound in red blood cells
  • globulin - a family of proteins found in blood and milk and muscle and in plant seed
  • glomerulus - a small intertwined group of capillaries in the malpighian body; it filters the blood during urine formation
  • glycosuria - the presence of abnormally high levels of sugar in the urine
  • gonad - a gland in which gametes (sex cells) are produced
  • gray matter - greyish nervous tissue containing cell bodies as well as fibers; forms the cerebral cortex consisting of unmyelinated neurons
  • great cerebral vein - a cerebral vein formed by the two internal cerebral veins and continuing into the sinus rectus
  • great saphenous vein - the longest vein in the body; runs from foot to the groin where it joins the femoral vein
  • gross anatomy - the study of the structure of the body and its parts without the use of a microscope
  • growth - vegetation that has grown
  • gustation - the faculty of distinguishing sweet, sour, bitter, and salty properties in the mouth
  • gyrus - a convex fold or elevation in the surface of the brain
  • hammer - the act of pounding (delivering repeated heavy blows)
  • haploid - of a cell or organism having a single set of chromosomes
  • heart block - recurrent sudden attacks of unconsciousness caused by impaired conduction of the impulse that regulates the heartbeat
  • heart rate - the rate at which the heart beats; usually measured to obtain a quick evaluation of a person's health
  • heat energy - a form of energy that is transferred by a difference in temperature
  • helper T cell - 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
  • hematocrit - a measuring instrument to determine (usually by centrifugation) the relative amounts of corpuscles and plasma in the blood
  • hematopoiesis - the formation of blood cells in the living body (especially in the bone marrow)
  • heme - a complex red organic pigment containing iron and other atoms to which oxygen binds
  • hemoglobin - a hemoprotein composed of globin and heme that gives red blood cells their characteristic color; function primarily to transport oxygen from the lungs to the body tissues
  • hemophilia - congenital tendency to uncontrolled bleeding; usually affects males and is transmitted from mother to son
  • hemopoiesis - the formation of blood cells in the living body (especially in the bone marrow)
  • hemorrhage - flow of blood from a ruptured blood vessels
  • hemosiderin - a granular brown substance composed of ferric oxide; left from the breakdown of hemoglobin; can be a sign of disturbed iron metabolism
  • hemostasis - surgical procedure of stopping the flow of blood (as with a hemostat)
  • heparin - a polysaccharide produced in basophils (especially in the lung and liver) and that inhibits the activity of thrombin in coagulation of the blood; it (trade names Lipo-Hepin and Liquaemin) is used as an anticoagulant in the treatment of thrombosis and in heart surgery
  • hepatic vein - a vein that drains the liver; empties into the vena cava
  • hilum - the scar on certain seeds marking its point of attachment to the funicle
  • histology - the branch of biology that studies the microscopic structure of animal or plant tissues
  • hole - an opening deliberately made in or through something
  • homeostasis - (physiology) metabolic equilibrium actively maintained by several complex biological mechanisms that operate via the autonomic nervous system to offset disrupting changes
  • hormone - the secretion of an endocrine gland that is transmitted by the blood to the tissue on which it has a specific effect
  • host - an animal or plant that nourishes and supports a parasite; it does not benefit and is often harmed by the association
  • hydrogen bond - a chemical bond consisting of a hydrogen atom between two electronegative atoms (e.g., oxygen or nitrogen) with one side be a covalent bond and the other being an ionic bond
  • hydrophilic - having a strong affinity for water; tending to dissolve in, mix with, or be wetted by water
  • hymen - a fold of tissue that partly covers the entrance to the vagina of a virgin
  • hypercalcemia - the presence of abnormally high levels of calcium in the blood; usually the result of excessive bone resorption in hyperparathyroidism or Paget's disease
  • hyperopia - abnormal condition in which vision for distant objects is better than for near objects
  • hyperpnea - energetic (deep and rapid) respiration that occurs normally after exercise or abnormally with fever or various disorders
  • hypertension - a common disorder in which blood pressure remains abnormally high (a reading of 140/90 mm Hg or greater)
  • hypertonic - (of a solution) having a higher osmotic pressure than a comparison solution
  • hypertrophic cardiomyopathy - a disorder in which the heart muscle is so strong that it does not relax enough to fill with the heart with blood and so has reduced pumping ability
  • hyperventilation - an increased depth and rate of breathing greater than demanded by the body needs; can cause dizziness and tingling of the fingers and toes and chest pain if continued
  • hypocalcemia - abnormally low level of calcium in the blood; associated with hypoparathyroidism or kidney malfunction or vitamin D deficiency
  • hypothalamus - a basal part of the diencephalon governing autonomic nervous system
  • hypothesis - a tentative theory about the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena
  • hypotonic - (of a solution) having a lower osmotic pressure than a comparison solution
  • hypovolemia - a blood disorder consisting of a decrease in the volume of circulating blood
  • hypoxia - a very strong drive resulting from a deficiency of available oxygen in the blood and bodily tissues (short of anoxia)
  • immune response - a bodily defense reaction that recognizes an invading substance (an antigen: such as a virus or fungus or bacteria or transplanted organ) and produces antibodies specific against that antigen
  • immune system - a system (including the thymus and bone marrow and lymphoid tissues) that protects the body from foreign substances and pathogenic organisms by producing the immune response
  • immunity - the quality of being unaffected by something
  • immunoglobulin - a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response
  • incus - the ossicle between the malleus and the stapes
  • inferior - of or characteristic of low rank or importance
  • inferior vena cava - receives blood from lower limbs and abdominal organs and empties into the posterior part of the right atrium of the heart; formed from the union of the two iliac veins
  • innate immunity - immunity to disease that occurs as part of an individual's natural biologic makeup
  • inner ear - a complex system of interconnecting cavities; concerned with hearing and equilibrium
  • inspiration - arousing to a particular emotion or action
  • intercostal artery - several arteries and supplying the intercostal spaces of the rib cage
  • intercostal vein - several veins draining the intercostal spaces of the rib cage
  • interferon - an antiviral protein produced by cells that have been invaded by a virus; inhibits replication of the virus
  • interleukin - any of several lymphokines that promote macrophages and killer T cells and B cells and other components of the immune system
  • internal carotid artery - the branch of the carotid artery that supplies blood to the brain and eyes and internal parts of the head
  • internal iliac 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
  • internal iliac vein - a vein that unites with the external iliac vein to form the common iliac vein
  • internal jugular vein - a continuation of the sigmoid sinus of the dura mater; joins the subclavian vein to form the brachiocephalic vein
  • internal respiration - the metabolic processes whereby certain organisms obtain energy from organic molecules; processes that take place in the cells and tissues during which energy is released and carbon dioxide is produced and absorbed by the blood to be transported to the lungs
  • intron - sequence of a eukaryotic gene's DNA that is not translated into a protein
  • inulin - used to manufacture fructose and in assessing kidney function
  • ion - a particle that is electrically charged (positive or negative); an atom or molecule or group that has lost or gained one or more electrons
  • ionic bond - a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains to electron to form a negative ion
  • iris - diaphragm consisting of thin overlapping plates that can be adjusted to change the diameter of a central opening
  • ischemia - local anemia in a given body part sometimes resulting from vasoconstriction or thrombosis or embolism
  • isotonic - of or involving muscular contraction in which tension is constant while length changes
  • isotope - one of two or more atoms with the same atomic number but with different numbers of neutrons
  • kidney - either of two bean-shaped excretory organs that filter wastes (especially urea) from the blood and excrete them and water in urine
  • kidney failure - inability of the kidneys to excrete wastes and to help maintain the electrolyte balance
  • kinesthesia - the perception of body position and movement and muscular tensions etc
  • kinetic energy - the mechanical energy that a body has by virtue of its motion
  • kinetochore - a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape
  • labor - productive work (especially physical work done for wages)
  • labyrinth - complex system of paths or tunnels in which it is easy to get lost
  • lactobacillus - Gram-positive rod-shaped bacteria that produce lactic acid especially in milk
  • lacuna - a blank gap or missing part
  • large intestine - beginning with the cecum and ending with the rectum; includes the cecum and the colon and the rectum; extracts moisture from food residues which are later excreted as feces
  • larynx - a cartilaginous structure at the top of the trachea; contains elastic vocal cords that are the source of the vocal tone in speech
  • lateral - lying away from the median and sagittal plane of a body
  • left gastric artery - a branch of the celiac artery that supplies the lesser curvature of the stomach and the abdominal part of the esophagus
  • lens - a transparent optical device used to converge or diverge transmitted light and to form images
  • leukemia - malignant neoplasm of blood-forming tissues; characterized by abnormal proliferation of leukocytes; one of the four major types of cancer
  • leukocyte - blood cells that engulf and digest bacteria and fungi; an important part of the body's defense system
  • leukocytosis - an abnormal increase in the number of white blood cells in the blood as a result of infection (as in leukemia)
  • leukopenia - an abnormal lowering of the white blood cell count
  • life science - any of the branches of natural science dealing with the structure and behavior of living organisms
  • light - characterized by or emitting light
  • light microscope - microscope consisting of an optical instrument that magnifies the image of an object
  • limbic system - a system of functionally related neural structures in the brain that are involved in emotional behavior
  • lipase - an enzyme secreted in the digestive tract that catalyzes the breakdown of fats into individual fatty acids that can be absorbed into the bloodstream
  • lipid - an oily organic compound insoluble in water but soluble in organic solvents; essential structural component of living cells (along with proteins and carbohydrates)
  • litmus - a coloring material (obtained from lichens) that turns red in acid solutions and blue in alkaline solutions; used as a very rough acid-base indicator
  • litmus paper - unsized paper treated with litmus for use as an acid-base indicator
  • liver - having a reddish-brown color
  • locus - the set of all points or lines that satisfy or are determined by specific conditions
  • locus - the set of all points or lines that satisfy or are determined by specific conditions
  • long bone - in limbs of vertebrate animals: a long cylindrical bone that contains marrow
  • lumbar artery - 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
  • lumbar vein - veins that drain the posterior body wall and the lumbar vertebral venous plexuses
  • lumen - a cavity or passage in a tubular organ
  • lung - either of two saclike respiratory organs in the chest of vertebrates; serves to remove carbon dioxide and provide oxygen to the blood
  • luteinizing hormone - a gonadotropic hormone that is secreted by the anterior pituitary; stimulates ovulation in female mammals and stimulates androgen release in male mammals
  • lymph - a thin coagulable fluid (similar to plasma but) containing white blood cells (lymphocytes) and chyle; is conveyed to the blood stream by lymphatic vessels
  • lymphocyte - an agranulocytic leukocyte that normally makes up a quarter of the white blood cell count but increases in the presence of infection
  • lymphoma - a neoplasm of lymph tissue that is usually malignant; one of the four major types of cancer
  • lysosome - an organelle found in the cytoplasm of most cells (especially in leukocytes and liver and kidney cells)
  • lysozyme - an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria
  • mRNA - the template for protein synthesis; the form of RNA that carries information from DNA in the nucleus to the ribosome sites of protein synthesis in the cell
  • macrophage - a large phagocyte; some are fixed and other circulate in the blood stream
  • malleus - the ossicle attached to the eardrum
  • mass number - the sum of the number of neutrons and protons in an atomic nucleus
  • mast cell - a large connective tissue cell that contains histamine and heparin and serotonin which are released in allergic reactions or in response to injury or inflammation
  • matter - (used with negation) having consequence
  • maxillary vein - posterior continuation of the pterygoid plexus; joins the superficial temporal vein to form the retromandibular vein
  • meatus - a natural body passageway
  • medial - dividing an animal into right and left halves
  • mediastinum - the part of the thoracic cavity between the lungs that contains the heart and aorta and esophagus and trachea and thymus
  • medulla - the inner part of an organ or structure in plant or animal
  • megakaryocyte - a large bone marrow cell; regarded as the source of blood platelets
  • meiosis - (genetics) cell division that produces reproductive cells in sexually reproducing organisms; the nucleus divides into four nuclei each containing half the chromosome number (leading to gametes in animals and spores in plants)
  • membrane - a thin pliable sheet of material
  • menarche - the first occurrence of menstruation in a woman
  • meninges - a membrane (one of 3) that envelops the brain and spinal cord
  • menopause - the time in a woman's life in which the menstrual cycle ends
  • menses - the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause
  • menstrual cycle - a recurring cycle (beginning at menarche and ending at menopause) in which the endometrial lining of the uterus prepares for pregnancy; if pregnancy does not occur the lining is shed at menstruation
  • mental illness - any disease of the mind; the psychological state of someone who has emotional or behavioral problems serious enough to require psychiatric intervention
  • mesoderm - the middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue
  • mesothelium - epithelium originating in the embryonic mesoderm; lines the primordial body cavity
  • messenger RNA - the template for protein synthesis; the form of RNA that carries information from DNA in the nucleus to the ribosome sites of protein synthesis in the cell
  • metabolism - the organic processes (in a cell or organism) that are necessary for life
  • metaphysis - the growing part of a long bone between the diaphysis and the epiphysis
  • microglia - neuroglial tissue of mesodermal origin that can become phagocytic
  • microscope - magnifier of the image of small objects
  • middle ear - the main cavity of the ear; between the eardrum and the inner ear
  • mineral - of or containing or derived from minerals
  • mineralocorticoid - hormone that is one of the steroids of the adrenal cortex that influences the metabolism of sodium and potassium
  • mitosis - cell division in which the nucleus divides into nuclei containing the same number of chromosomes
  • mitotic - of or relating to or undergoing mitosis
  • mitral valve - valve with two cusps; situated between the left atrium and the left ventricle
  • modeling - a preliminary sculpture in wax or clay from which a finished work can be copied
  • molecular biology - the branch of biology that studies the structure and activity of macromolecules essential to life (and especially with their genetic role)
  • mons pubis - a mound of fatty tissue covering the pubic area in women
  • morning sickness - nausea early in the day; a characteristic symptom in the early months of pregnancy
  • motor end plate - the flattened end of a motor neuron that transmits neural impulses to a muscle
  • mouth - the opening of a jar or bottle
  • movement - the act of changing the location of something
  • mucus - 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
  • murmur - a schwa that is incidental to the pronunciation of a consonant
  • muscle contraction - (physiology) a shortening or tensing of a part or organ (especially of a muscle or muscle fiber)
  • musculoskeletal system - the system of muscles and tendons and ligaments and bones and joints and associated tissues that move the body and maintain its form
  • myocardium - the middle muscular layer of the heart wall
  • myometrium - the smooth muscle forming the wall of the uterus
  • myopia - (ophthalmology) eyesight abnormality resulting from the eye's faulty refractive ability; distant objects appear blurred
  • myosin - the commonest protein in muscle; a globulin that combines with actin to form actomyosin
  • nasal bone - an elongated rectangular bone that forms the bridge of the nose
  • nasal septum - a partition of bone and cartilage between the nasal cavities
  • nasopharynx - cavity forming the upper part of the pharynx
  • natural science - the sciences involved in the study of the physical world and its phenomena
  • nephrology - the branch of medicine concerned with the kidney - its development and anatomy and physiology and disorders
  • nephron - any of the small tubules that are the excretory units of the vertebrate kidney
  • nervous system - the sensory and control apparatus consisting of a network of nerve cells
  • neurologist - a medical specialist in the nervous system and the disorders affecting it
  • neuron - a cell that is specialized to conduct nerve impulses
  • neutron - an elementary particle with 0 charge and mass about equal to a proton; enters into the structure of the atomic nucleus
  • neutrophil - the chief phagocytic leukocyte; stains with either basic or acid dyes
  • node - (computer science) any computer that is hooked up to a computer network
  • node - (computer science) any computer that is hooked up to a computer network
  • norepinephrine - a catecholamine precursor of epinephrine that is secreted by the adrenal medulla and also released at synapses
  • nose - a front that resembles a human nose (especially the front of an aircraft)
  • nucleic acid - (biochemistry) any of various macromolecules composed of nucleotide chains that are vital constituents of all living cells
  • nucleolus - a small round body of protein in a cell nucleus; such organelles contain RNA and are involved in protein synthesis
  • nucleotide - a phosphoric ester of a nucleoside; the basic structural unit of nucleic acids (DNA or RNA)
  • nucleus - a part of the cell containing DNA and RNA and responsible for growth and reproduction
  • nutrition - the scientific study of food and drink (especially in humans)
  • occipital lobe - that part of the cerebral cortex in either hemisphere of the brain lying in the back of the head
  • odor - any property detected by the olfactory system
  • olfaction - the faculty that enables us to distinguish scents
  • olfactory bulb - one of two enlargements at the terminus of the olfactory nerve at the base of the brain just above the nasal cavities
  • oliguria - production of an abnormally small amount of urine
  • omega-3 - a polyunsaturated fatty acid whose carbon chain has its first double valence bond three carbons from the beginning
  • oncogene - a gene that causes normal cells to change into cancerous tumor cells
  • oocyte - a female gametocyte that develops into an ovum after two meiotic divisions
  • ophthalmic artery - a branch of the internal carotid artery that supplies the eye and neighboring structures
  • opsonization - process whereby opsonins make an invading microorganism more susceptible to phagocytosis
  • oral cavity - the opening through which food is taken in and vocalizations emerge
  • organ - wind instrument whose sound is produced by means of pipes arranged in sets supplied with air from a bellows and controlled from a large complex musical keyboard
  • organ of Corti - the hearing organ of the inner ear; contains receptors that respond to sound waves
  • organelle - a specialized part of a cell; analogous to an organ
  • organism - a living thing that has (or can develop) the ability to act or function independently
  • orgasm - the moment of most intense pleasure in sexual intercourse
  • origin - properties attributable to your ancestry
  • oropharynx - cavity formed by the pharynx at the back of the mouth
  • orthopedist - a specialist in correcting deformities of the skeletal system (especially in children)
  • osmosis - diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal
  • osmotic pressure - (physical chemistry) the pressure exerted by a solution necessary to prevent osmosis into that solution when it is separated from the pure solvent by a semipermeable membrane
  • osseous tissue - the porous calcified substance from which bones are made
  • ossicle - a small bone; especially one in the middle ear
  • osteoclast - cell that functions in the breakdown and resorption of bone tissue
  • osteogenesis imperfecta - autosomal dominant disorder of connective tissue characterized by brittle bones that fracture easily
  • osteomalacia - abnormal softening of bones caused by deficiencies of phosphorus or calcium or vitamin D
  • osteoporosis - abnormal loss of bony tissue resulting in fragile porous bones attributable to a lack of calcium; most common in postmenopausal women
  • outer ear - the part of the ear visible externally
  • oval window - fenestra that has the base of the stapes attached to it
  • ovarian artery - the artery that branches from the aorta and supplies blood to the ovaries
  • ovarian vein - one of the veins that drain the ovaries; the right opens into the inferior vena cava; the left opens into the left renal vein
  • ovary - (vertebrates) one of usually two organs that produce ova and secrete estrogen and progesterone
  • oviduct - either of a pair of tubes conducting the egg from the ovary to the uterus
  • ovulation - the expulsion of an ovum from the ovary (usually midway in the menstrual cycle)
  • ovum - the female reproductive cell; the female gamete
  • oxygen - a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
  • pH scale - (from potential of Hydrogen) the logarithm of the reciprocal of hydrogen-ion concentration in gram atoms per liter; provides a measure on a scale from 0 to 14 of the acidity or alkalinity of a solution (where 7 is neutral and greater than 7 is more basic and less than 7 is more acidic)
  • papilla - a small projection of tissue at the base of a hair or tooth or feather
  • papillary muscle - any of several muscles associated with the atrioventricular valves
  • paranasal sinus - any of the paired sinuses in the bones of the face adjacent to the nasal cavity that are lined with mucous membrane that is continuous with the lining of the nasal cavities
  • parasympathetic nervous system - originates in the brain stem and lower part of the spinal cord; opposes physiological effects of the sympathetic nervous system: stimulates digestive secretions; slows the heart; constricts the pupils; dilates blood vessels
  • parathyroid gland - any one of four endocrine glands situated above or within the thyroid gland
  • parathyroid hormone - 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
  • parietal lobe - that part of the cerebral cortex in either hemisphere of the brain lying below the crown of the head
  • passive immunity - an impermanent form of acquired immunity in which antibodies against a disease are acquired naturally (as through the placenta to an unborn child) or artificially (as by injection of antiserum)
  • passive transport - transport of a substance across a cell membrane by diffusion; expenditure of energy is not required
  • pathogen - any disease-producing agent (especially a virus or bacterium or other microorganism)
  • pedicel - a small stalk bearing a single flower of an inflorescence; an ultimate division of a common peduncle
  • pelvic inflammatory disease - inflammation of the female pelvic organs (especially the Fallopian tubes) caused by infection by any of several microorganisms (chiefly gonococci and chlamydia); symptoms are abdominal pain and fever and foul-smelling vaginal discharge
  • penis - the male organ of copulation (`member' is a euphemism)
  • pepsin - an enzyme produced in the stomach that splits proteins into peptones
  • perfusion - pumping a liquid into an organ or tissue (especially by way of blood vessels)
  • pericardial cavity - the space between the layers of the pericardium that contains fluid that lubricates the membrane surfaces and allows easy heart movement
  • pericardium - a serous membrane with two layers that surrounds the heart
  • periodic table - a tabular arrangement of the chemical elements according to atomic number as based on the periodic law
  • periosteum - a dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles; contains nerves and blood vessels that nourish the enclosed bone
  • peristalsis - the process of wavelike muscle contractions of the alimentary tract that moves food along
  • peritoneal cavity - the interior of the peritoneum; a potential space between layers of the peritoneum
  • peritoneum - a transparent membrane that lines the abdominal cavity in mammals and covers most of the viscera
  • phagocytosis - process in which phagocytes engulf and digest microorganisms and cellular debris; an important defense against infection
  • pharyngeal tonsil - a collection of lymphatic tissue in the throat behind the uvula (on the posterior wall and roof of the nasopharynx)
  • pharynx - the passage to the stomach and lungs; in the front part of the neck below the chin and above the collarbone
  • phase - (astronomy) the particular appearance of a body's state of illumination (especially one of the recurring shapes of the part of Earth's moon that is illuminated by the sun)
  • pheromone - a chemical substance secreted externally by some animals (especially insects) that influences the physiology or behavior of other animals of the same species
  • phlebotomy - surgical incision into a vein; used to treat hemochromatosis
  • phospholipid - any of various compounds composed of fatty acids and phosphoric acid and a nitrogenous base; an important constituent of membranes
  • photosynthesis - synthesis of compounds with the aid of radiant energy (especially in plants)
  • physiological sphincter - a sphincter that is not recognizable at autopsy because its resting arrangement cannot be distinguished from adjacent tissue
  • physiology - processes and functions of an organism
  • pia mater - the highly vascular innermost of the 3 meninges
  • pinna - division of a usually pinnately divided leaf
  • pinocytosis - process by which certain cells can engulf and incorporate droplets of fluid
  • pituitary gland - the master gland of the endocrine system; located at the base of the brain
  • placenta - the vascular structure in the uterus of most mammals providing oxygen and nutrients for and transferring wastes from the developing fetus
  • plane - having a surface without slope, tilt in which no part is higher or lower than another
  • plasma - colorless watery fluid of blood and lymph containing no cells and in which erythrocytes and leukocytes and platelets are suspended
  • plasma cell - a cell that develops from a B lymphocyte in reaction to a specific antigen; found in bone marrow and sometimes in the blood
  • plasma membrane - a thin membrane (a double layer of lipids) enclosing the cytoplasm of a cell; proteins in the membrane control passage of ions (like sodium or potassium or calcium) in and out of the cell
  • plasmin - an enzyme that dissolves the fibrin of blood clots
  • platelet - tiny bits of protoplasm found in vertebrate blood; essential for blood clotting
  • pleura - the thin serous membrane around the lungs and inner walls of the chest
  • pleural cavity - the cavity in the thorax that contains the lungs and heart
  • polar body - a small cell containing little cytoplasm that is produced along with the oocyte and later discarded
  • polycythemia - a disorder characterized by an abnormal increase in the number of red blood cells in the blood
  • polypeptide - a peptide containing 10 to more than 100 amino acids
  • polysaccharide - any of a class of carbohydrates whose molecules contain chains of monosaccharide molecules
  • polyuria - renal disorder characterized by the production of large volumes of pale dilute urine; often associated with diabetes
  • popliteal artery - continuation of the femoral artery that branches to supply the legs and feet
  • popliteal vein - a vein arising in the knee and ascending to become the femoral vein
  • population - the act of populating (causing to live in a place)
  • positron emission tomography - using a computerized radiographic technique to examine the metabolic activity in various tissues (especially in the brain)
  • posterior - at or near the hind end in quadrupeds or toward the spine in primates
  • potential energy - the mechanical energy that a body has by virtue of its position; stored energy
  • prepuce - a fold of skin covering the tip of the penis
  • presbyopia - farsightedness resulting from a reduced ability to focus caused by loss of elasticity of the crystalline lens with age
  • primer - an introductory textbook
  • progesterone - a steroid hormone (trade name Lipo-Lutin) produced in the ovary; prepares and maintains the uterus for pregnancy
  • projection - any structure that branches out from a central support
  • prokaryote - a unicellular organism having cells lacking membrane-bound nuclei; bacteria are the prime example but also included are blue-green algae and actinomycetes and mycoplasma
  • promoter - someone who is an active supporter and advocate
  • prone - lying face downward
  • proprioception - the ability to sense the position and location and orientation and movement of the body and its parts
  • prostate gland - 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
  • protection - payment extorted by gangsters on threat of violence
  • protein - any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes
  • proto-oncogene - a normal gene that has the potential to become an oncogene
  • proton - a stable particle with positive charge equal to the negative charge of an electron
  • proximal - situated nearest to point of attachment or origin
  • pulmonary artery - one of two arteries (branches of the pulmonary trunk) that carry venous blood from the heart to the lungs
  • pulmonary trunk - the artery that carries venous blood from the right ventricle of the heart and divides into the right and left pulmonary arteries
  • pulmonary valve - a semilunar valve between the right ventricle and the pulmonary artery; prevents blood from flowing from the artery back into the heart
  • pulmonary vein - any of four veins that carry arterial blood from the lungs to the left atrium of the heart
  • pulse - the rhythmic contraction and expansion of the arteries with each beat of the heart
  • pupil - contractile aperture in the iris of the eye
  • radial vein - superficial veins ascending the radial side of the forearm; combines with the ulnar veins to form the brachial vein
  • reabsorption - the organic process in which the substance of some differentiated structure that has been produced by the body undergoes lysis and assimilation
  • receptor - a cellular structure that is postulated to exist in order to mediate between a chemical agent that acts on nervous tissue and the physiological response
  • rectum - the terminal section of the alimentary canal; from the sigmoid flexure to the anus
  • red blood cell - a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus
  • red marrow - bone marrow of children and some adult bones that is required for the formation of red blood cells
  • reduction division - (genetics) cell division that produces reproductive cells in sexually reproducing organisms; the nucleus divides into four nuclei each containing half the chromosome number (leading to gametes in animals and spores in plants)
  • refractory period - (neurology) the time after a neuron fires or a muscle fiber contracts during which a stimulus will not evoke a response
  • regional anatomy - the study of anatomy based on regions or divisions of the body and emphasizing the relations between various structures (muscles and nerves and arteries etc.) in that region
  • renal - of or relating to the kidneys
  • renal artery - an artery originating from the abdominal aorta and supplying the kidneys and adrenal glands and ureters
  • renal corpuscle - the capsule that contains Bowman's capsule and a glomerulus at the expanded end of a nephron
  • renal cortex - the cortex of the kidney containing the glomeruli and the convoluted tubules
  • renal pelvis - a structure shaped like a funnel in the outlet of the kidney into which urine is discharged before passing into the ureter
  • renal vein - veins that accompany renal arteries; open into the vena cava at the level of the 2nd lumbar vertebra
  • renin - a proteolytic enzyme secreted by the kidneys; catalyzes the formation of angiotensin and thus affects blood pressure
  • reproduction - the sexual activity of conceiving and bearing offspring
  • resistance - the action of opposing something that you disapprove or disagree with
  • respiratory rate - the rate at which a person inhales and exhales; usually measured to obtain a quick evaluation of a person's health
  • responsiveness - the quality of being responsive; reacting quickly; as a quality of people, it involves responding with emotion to people and events
  • rhodopsin - a red photopigment in the retinal rods of vertebrates; dissociates into retinene by light
  • ribonucleic acid - (biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes; it transmits genetic information from DNA to the cytoplasm and controls certain chemical processes in the cell
  • ribonucleic acid - (biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes; it transmits genetic information from DNA to the cytoplasm and controls certain chemical processes in the cell
  • ribosome - an organelle in the cytoplasm of a living cell; they attach to mRNA and move down it one codon at a time and then stop until tRNA brings the required amino acid; when it reaches a stop codon it falls apart and releases the completed protein molecule for use by the cell
  • right atrioventricular valve - valve with three cusps; situated between the right atrium and the right ventricle; allows blood to pass from atrium to ventricle and closes to prevent backflow when the ventricle contracts
  • right atrium - the right upper chamber of the heart that receives blood from the venae cavae and coronary sinus
  • right gastric artery - a branch of the hepatic artery that supplies the pyloric portion of the stomach on the lesser curvature
  • right ventricle - the chamber on the right side of the heart that receives venous blood from the right atrium and pumps it into the pulmonary trunk
  • rod - any rod-shaped bacterium
  • root - the part of a tooth that is embedded in the jaw and serves as support
  • salivary gland - any of three pairs of glands in the mouth and digestive system that secrete saliva for digestion
  • salty - containing or filled with salt
  • sarcolemma - an extensible membrane enclosing the contractile substance of a muscle fiber
  • sarcomere - one of the segments into which a myofibril is divided
  • saturated fatty acid - a fatty acid whose carbon chain cannot absorb any more hydrogen atoms; found chiefly in animal fats
  • schizophrenia - any of several psychotic disorders characterized by distortions of reality and disturbances of thought and language and withdrawal from social contact
  • science - a particular branch of scientific knowledge
  • scrotum - the external pouch that contains the testes
  • semen - the thick white fluid containing spermatozoa that is ejaculated by the male genital tract
  • semicircular canal - one of three tube loops filled with fluid and in planes nearly at right angles with one another; concerned with equilibrium
  • seminal vesicle - either of a pair of glands located on either side of the male urinary bladder that open into the vas deferens and that secrete many components of semen during ejaculation
  • seminiferous tubule - any of the numerous long convoluted tubules in the testis which are the sites where spermatozoa mature
  • sense - the faculty through which the external world is apprehended
  • sensor - any device that receives a signal or stimulus (as heat or pressure or light or motion etc.) and responds to it in a distinctive manner
  • sensory receptor - an organ having nerve endings (in the skin or viscera or eye or ear or nose or mouth) that respond to stimulation
  • sepsis - the presence of pus-forming bacteria or their toxins in the blood or tissues
  • septum - (anatomy) a dividing partition between two tissues or cavities
  • serous membrane - a thin membrane lining the closed cavities of the body; has two layers with a space between that is filled with serous fluid
  • serum - watery fluid of the blood that resembles plasma but contains fibrinogen
  • sesamoid bone - any of several small round bones formed in a tendon where it passes over a joint
  • set point - (tennis) the final point needed to win a set in tennis
  • short bone - a bone that is of approximately equal dimension in all directions
  • sight - a optical instrument for aiding the eye in aiming, as on a firearm or surveying instrument
  • sigmoid sinus - an S-shaped dural sinus on the temporal and occipital bones
  • simple sugar - a sugar (like sucrose or fructose) that does not hydrolyse to give other sugars; the simplest group of carbohydrates
  • singular - being a single and separate person or thing
  • sinoatrial node - a specialized bit of heart tissue that controls the heartbeat
  • sinus - any of various air-filled cavities especially in the bones of the skull
  • sinusoid - tiny endothelium-lined passages for blood in the tissue of an organ
  • skeletal system - the hard structure (bones and cartilages) that provides a frame for the body of an animal
  • small intestine - the longest part of the alimentary canal; where digestion is completed
  • smell - the act of perceiving the odor of something
  • solute - the dissolved substance in a solution; the component of a solution that changes its state
  • solvent - capable of meeting financial obligations
  • somatic cell - any of the cells of a plant or animal except the reproductive cells; a cell that does not participate in the production of gametes
  • sour - smelling of fermentation or staleness
  • sperm - the male reproductive cell; the male gamete
  • spermatic cord - a structure resembling a cord that suspends the testis within the scrotum and contains the vas deferens and other vessels and nerves
  • spermatid - an immature gamete produced by a spermatocyte; develops into a spermatozoon
  • spermatocyte - a male gametocyte that develops into four spermatids
  • spinal cord - a major part of the central nervous system which conducts sensory and motor nerve impulses to and from the brain; a long tubelike structure extending from the base of the brain through the vertebral canal to the upper lumbar region
  • spinal nerve - any of the 31 pairs of nerves emerging from each side of the spinal cord (each attached to the cord by two roots: ventral and dorsal)
  • splenic artery - an artery that originates from the celiac trunk and supplies blood to the spleen
  • splicing - a junction where two things (as paper or film or magnetic tape) have been joined together
  • steroid - any of several fat-soluble organic compounds having as a basis 17 carbon atoms in four rings; many have important physiological effects
  • stimulus - any stimulating information or event; acts to arouse action
  • stirrup - support consisting of metal loops into which rider's feet go
  • stomach - an enlarged and muscular saclike organ of the alimentary canal; the principal organ of digestion
  • stroke - a light touch with the hands
  • subclavian vein - a continuation of the axillary vein; joins the internal jugular to form the brachiocephalic vein
  • substrate - an indigenous language that contributes features to the language of an invading people who impose their language on the indigenous population
  • sulcus - (anatomy) any of the narrow grooves in an organ or tissue especially those that mark the convolutions on the surface of the brain
  • summation - the arithmetic operation of summing; calculating the sum of two or more numbers
  • superior mesenteric artery - originates from the upper part of the aorta that supplies the small intestines and the cecum and the colon
  • superior vena cava - 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
  • support - a military operation (often involving new supplies of men and materiel) to strengthen a military force or aid in the performance of its mission
  • surface tension - a phenomenon at the surface of a liquid caused by intermolecular forces
  • sweet - pleasing to the senses
  • sympathetic nervous system - originates in the thoracic regions of the spinal cord; opposes physiological effects of the parasympathetic: reduces digestive secretions; speeds the heart; contracts blood vessels
  • synapse - the junction between two neurons (axon-to-dendrite) or between a neuron and a muscle
  • synapsis - the side by side pairing of homologous maternal and paternal chromosomes at the start of meiosis
  • systole - the contraction of the chambers of the heart (especially the ventricles) to drive blood into the aorta and pulmonary artery
  • systolic pressure - the blood pressure (as measured by a sphygmomanometer) during the contraction of the left ventricle of the heart
  • tRNA - RNA molecules present in the cell (in at least 20 varieties, each variety capable of combining with a specific amino acid) that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell (according to directions coded in the mRNA)
  • tachycardia - abnormally rapid heartbeat (over 100 beats per minute)
  • taste - a kind of sensing; distinguishing substances by means of the taste buds
  • taste bud - an oval sensory end organ on the surface of the tongue
  • telomerase - an enzyme in eukaryotic cells that can add telomeres to the ends of chromosomes after they divide
  • telomere - either (free) end of a eukaryotic chromosome
  • temperature - the degree of hotness or coldness of a body or environment (corresponding to its molecular activity)
  • temporal lobe - that part of the cerebral cortex in either hemisphere of the brain lying inside the temples of the head
  • temporal vein - any of several veins draining the temporal region
  • testicle - one of the two male reproductive glands that produce spermatozoa and secrete androgens
  • testis - one of the two male reproductive glands that produce spermatozoa and secrete androgens
  • testosterone - a potent androgenic hormone produced chiefly by the testes; responsible for the development of male secondary sex characteristics
  • thalamus - large egg-shaped structures of grey matter that form the dorsal subdivision of the diencephalon
  • thalassemia - an inherited form of anemia caused by faulty synthesis of hemoglobin
  • thermodynamics - the branch of physics concerned with the conversion of different forms of energy
  • thoracic aorta - a branch of the descending aorta; divides into the iliac arteries
  • thoracic cavity - the cavity in the vertebrate body enclosed by the ribs between the diaphragm and the neck and containing the lungs and heart
  • thrombin - an enzyme that acts on fibrinogen in blood causing it to clot
  • thrombocyte - tiny bits of protoplasm found in vertebrate blood; essential for blood clotting
  • thrombocytopenia - a blood disease characterized by an abnormally small number of platelets in the blood
  • thrombocytosis - increase in the number of platelets in the blood which tends to cause clots to form; associated with many neoplasms and chronic infections and other diseases
  • thrombosis - the formation or presence of a thrombus (a clot of coagulated blood attached at the site of its formation) in a blood vessel
  • thrombus - a blood clot formed within a blood vessel and remaining attached to its place of origin
  • thymus gland - a ductless glandular organ at the base of the neck that produces lymphocytes and aids in producing immunity; atrophies with age
  • tissue - part of an organism consisting of an aggregate of cells having a similar structure and function
  • tonicity - the elastic tension of living muscles, arteries, etc. that facilitate response to stimuli
  • trabecula - rod-shaped structures of fibrous tissue that divide an organ into parts (as in the penis) or stabilize the structure of an organ (as in the spleen)
  • trachea - membranous tube with cartilaginous rings that conveys inhaled air from the larynx to the bronchi
  • transcription - a sound or television recording (e.g., from a broadcast to a tape recording)
  • transduction - the process whereby a transducer accepts energy in one form and gives back related energy in a different form
  • transfer RNA - RNA molecules present in the cell (in at least 20 varieties, each variety capable of combining with a specific amino acid) that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell (according to directions coded in the mRNA)
  • transferrin - a globulin in blood plasma that carries iron
  • transient ischemic attack - brief episode in which the brain gets insufficient blood supply; symptoms depend on the site of the blockage
  • tricuspid valve - valve with three cusps; situated between the right atrium and the right ventricle; allows blood to pass from atrium to ventricle and closes to prevent backflow when the ventricle contracts
  • triglyceride - glyceride occurring naturally in animal and vegetable tissues; it consists of three individual fatty acids bound together in a single large molecule; an important energy source forming much of the fat stored by the body
  • trimester - one of three divisions of an academic year
  • true vocal cord - either of the two lower vocal folds that come together to form the glottis; produce a vocal tone when they are approximated and air from the lungs passes between them
  • trunk - luggage consisting of a large strong case used when traveling or for storage
  • tympanum - a large hemispherical brass or copper percussion instrument with a drumhead that can be tuned by adjusting the tension on it
  • ultrasonography - using the reflections of high-frequency sound waves to construct an image of a body organ (a sonogram); commonly used to observe fetal growth or study bodily organs
  • ultrasound - very high frequency sound; used in ultrasonography
  • umbilical vein - a vein in the umbilical cord; returns nutrient blood from the placenta to the fetus
  • universal donor - a person whose type O Rh-negative blood may be safely transfused into persons with other blood types
  • ureter - either of a pair of thick-walled tubes that carry urine from the kidney to the urinary bladder
  • urethra - duct through which urine is discharged in most mammals and which serves as the male genital duct
  • urinalysis - (medicine) the chemical analysis of urine (for medical diagnosis)
  • urine - liquid excretory product
  • uterine tube - either of a pair of tubes conducting the egg from the ovary to the uterus
  • uterus - a hollow muscular organ in the pelvic cavity of females; contains the developing fetus
  • vacuole - a tiny cavity filled with fluid in the cytoplasm of a cell
  • vagina - the lower part of the female reproductive tract; a moist canal in female mammals extending from the labia minora to the uterus
  • valve - control consisting of a mechanical device for controlling the flow of a fluid
  • variable - (used of a device) designed so that a property (as e.g. light) can be varied
  • varicose vein - a vein that is permanently dilated; most common in the legs
  • vas deferens - a duct that carries spermatozoa from the epididymis to the ejaculatory duct
  • vasa vasorum - any small blood vessel ramifying on the outside of a major artery or vein
  • vasectomy - surgical procedure that removes all or part of the vas deferens (usually as a means of sterilization); is sometimes reversible
  • vasodilation - dilation of blood vessels (especially the arteries)
  • vasodilator - a drug that causes dilation of blood vessels
  • vasopressin - 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
  • vein - one of the horny ribs that stiffen and support the wing of an insect
  • ventilation - the act of supplying fresh air and getting rid of foul air
  • ventral - toward or on or near the belly (front of a primate or lower surface of a lower animal)
  • ventricle - a chamber of the heart that receives blood from an atrium and pumps it to the arteries
  • venule - a minute vein continuous with a capillary
  • vertebral artery - the first branch of the subclavian artery; divided into four parts
  • vertebral vein - a vein that goes through the foramina of the cervical vertebrae and forms a plexus around the vertebral artery; empties into the brachiocephalic vein
  • vesicle - a small anatomically normal sac or bladderlike structure (especially one containing fluid)
  • vestibular fold - either of the upper two vocal cords that are not involved in vocalization
  • vestibular sense - a sensory system located in structures of the inner ear that registers the orientation of the head
  • vision - the perceptual experience of seeing
  • vital capacity - the maximum amount of air that can be exhaled after a maximum inhalation (usually tested with a spirometer); used to determine the condition of lung tissue
  • vitamin - any of a group of organic substances essential in small quantities to normal metabolism
  • vitamin D - a fat-soluble vitamin that prevents rickets
  • vocal cord - either of two pairs of folds of mucous membrane projecting into the larynx
  • vulva - external parts of the female genitalia
  • white blood cell - blood cells that engulf and digest bacteria and fungi; an important part of the body's defense system
  • white matter - whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths

See also

Glossary of biology

Medical dictionary
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