A small solid projection of tissue on the outer surface of the testis which is a remnant of the embryologic mullerian duct.
1. The final stage of attentive perception in which something is clearly apprehended and thus is relatively prominent in awareness; the full apprehension of any psychic content. ...
Relating to, involved in, or capable of apperception.
The mechanism in the brain (possibly in the hypothalamus) concerned with the appetite and control of food intake. [appetite + G. statos, standing]
A desire or motive derived from a biologic or psychological need for food, water, sex, or affection; a desire or longing to satisfy any conscious physical or mental need. SYN: ...
In tonometry, the flattening of the cornea by pressure. Intraocular pressure is directly proportional to external pressure, and inversely proportional to the area flattened. SEE ...
A device used to improve function of a part, or for therapeutic purposes. [fr, O. Fr. aplier, to apply, fr. L. applico, to fold together]
- craniofacial a. a device used to ...
Abbreviation for applicandus, to be applied. [L.]
A slender rod of wood, flexible metal, or synthetic material, at one end of which is attached a pledget of cotton or other substance for making local applications to any ...
The word "apposition" has several senses including the act of adding or accretion and also the putting of things in juxtaposition, or side by side. Growth by apposition is a ...
1. In psychiatry, a term used to describe how interpersonal relationships are negotiated. 2. The path or method used to expose the operative field during an operation. [M.E., ...
To bring close together. In dentistry : 1. Proximate, denoting the contact surfaces, either mesial or distal, of two adjacent teeth. 2. Close together; denoting the teeth in the ...
In surgery, bringing tissue edges into desired apposition for suturing.
- steady state a. an assumption in the derivation of an enzyme rate expression in which the rate of ...
Abbreviation for abdominoperineal resection.
SYN: constructional apraxia. [G. a- priv. + praktea, things to be done, + gnosis, recognition]
An interest in theory or dogmatism rather than in practical results. [G. a- priv. + pragmatism]
The inability to execute a voluntary motor movement despite being able to demonstrate normal muscle function. Apraxia is not related to a lack of understanding or to any kind of ...
Apraxia of speech
A severe speech disorder characterized by inability to speak, or a severe struggle to speak clearly. Apraxia of speech occurs when the oral- motor muscles do not or cannot obey ...
Marked by or pertaining to apraxia. SYN: apractic.
Congenital absence or imperforation of the anus. [G. a- priv. + proktos, anus]
Absence, in speech, of the normal pitch, rhythm, and variations in stress. [G. a- priv. + prosodia, voice modulation]
Congenital absence of the greater part or all of the face, usually associated with other malformations. [G. a- priv. + prosopon, face]
A protease and kallikrein inhibitor obtained from animal organs; a polypeptide with a molecular weight of about 6000. May be useful in the treatment of pancreatitis and in ...
Abbreviation for adenosine 5′-phosphosulfate.
APS (autoimmune polyglandular syndrome)
1. A genetic autoimmune disease with an extraordinary array of clinical features but characterized most often by at least 2 of the following 3 findings: hypoparathyroidism — ...
Abbreviation for activated partial thromboplastin time.
Proposed designation for a group of cells in different organs secreting polypeptide hormones or neurotransmitters. Cells in this group have certain biochemical characteristics in ...
DNA from which the purine bases have been removed by mild acid treatment.
Denoting a cell or other structure that does not stain deeply because the stainable or chromophil material is not closely aggregated. [G. a- priv. + pyknos, thick, + morphe, ...
An enzyme catalyzing hydrolytic removal of two orthophosphate residues from adenosine 5′-triphosphate to yield adenosine 5′-monophosphate; i.e., ATP + 2H2O → AMP + 2Pi. ...
Absence of fever. [G. a- priv. + pyrexis, fever]
DNA from which the pyrimidine bases have been removed by chemical treatment ( e.g., exposure to hydrazine).
Abbreviation for L. aqua, water.
Abbreviation for L. aqua bulliens, boiling water.
Abbreviation for L. aqua destillata, distilled water.
Abbreviation for L. aqua fervens, hot water.
Abbreviation for L. aqua frigida, cold water.
H2O. Pharmaceutical waters, aquae, are aqueous solutions of volatile substances ( e.g., rose water). Pharmaceutical solutions, liquors, are aqueous solutions of nonvolatile ...
Vitamin B12a ( tautomeric with B12b); a cobalamin derivative in which the sixth coordinate bond of the cobaltic ion is attached to a water molecule. SEE ALSO: vitamin B12. SYN: ...
An abnormal and persistent fear of water. Sufferers from aquaphobia experience anxiety even though they realize the water in an ocean, a river, a lake, a creek or even a bathtub ...
Rarely used term for a hypodermic injection of water. [L. aqua, water, + punctura, puncture]
A genus of motile, nonsporeforming, aerobic bacteria (family Spirillaceae) containing Gram-negative, rigid, helical or helically curved cells that are 0.2–1.5 μm in diameter. ...
1. Of or pertaining to water. 2. Denoting an organism that lives in water.
A conduit or canal. SYN: aqueductus. [L. aquaeductus]
- cerebral a. an ependyma-lined canal in the mesencephalon about 20 mm long, connecting the third to the fourth ventricle. ...
Aqueduct of Sylvius
A canal that communicates between the third and fourth ventricles in a system of four communicating cavities within the brain that are continuous with the central canal of the ...
Aqueduct of the midbrain
A canal that communicates between the third and fourth ventricles in a system of four communicating cavities within the brain that are continuous with the central canal of the ...
SYN: aqueduct. [L. fr. aqua, water, + ductus, a leading, fr. duco, pp. ductus, to lead]
- a. cerebri [offalt] cerebral aqueduct.
- a. cochleae [TA] SYN: cochlear aqueduct.
Watery; of, like, or containing water.
In medicine, humor refers to a fluid (or semifluid) substance. Thus, the aqueous humor is the fluid normally present in the front and rear chambers of the eye. It is a clear, ...
Secreting or excreting a watery fluid. [L. aqua, water, + pario, to bring forth]
A hydrated ion; an ion containing one or more water molecules; e.g., Cu(H2O)42+.
1. The state of being watery. 2. Moisture.
Symbol for arabinose, or its mono- or diradical.
Prefix for arabinose or arabinosyl.
Gum arabic; similar gummy substances. [G. Araps, Arabos, an Arab]
A polysaccharide that yields arabinose on hydrolysis; a constituent of some pectins.
Relating to or derived from various species of Acacia having a gummy or resinous exudate.
Arabidopsis thaliana genome
All of the genetic information contained in Arabidopsis thaliana, a plant belonging to the mustard family. The genomes of particular nonhuman organisms such as Arabidopsis have ...
A carbohydrate gum, hydrolyzing to d-arabinose and hexoses, found naturally in union with calcium, potassium, and magnesium ions, when it is called gum arabic. SYN: arabic ...
A pentose; both of its enantiomers are widely distributed in plants, usually in complex polysaccharides; used in culture media. d- A. is an epimer of d-ribose. [ arabin + -ose ...
A ribonucleoside in which the sugar moiety is arabinose. It often has antibiotic activity.
Used for herpes simplex corneae and vaccinial keratitis. SYN: arabinoadenosine.
A compound of arabinose and cytosine, analogous to ribosylcytosine (cytidine), that inhibits the biosynthesis of DNA; used as a chemotherapeutic agent because of antiviral ...
A sugar alcohol obtained from the reduction of arabinose.
Abbreviation for cytosine arabinoside.
Symbol for arabinosylcytosine.
A fatty acid contained in peanut oil, butter, and other fats. SYN: arachic acid, n-eicosanoic acid, n-icosanoic acid. [Arachis, fr. G. arakis, leguminous weed]
5,8,11,14-Eicosatetraenoic (icosatetraenoic) acid; an unsaturated fatty acid, usually essential in nutrition; the biological precursor of the prostaglandins, the thromboxanes, ...
Morbid fear of spiders. SYN: arachnophobia. [G. arachne, spider, + phobos, fear]
A genus of nonmotile, nonsporeforming, facultatively anaerobic bacteria (family Actinomycetaceae) containing Gram-positive, non–acid-fast, branched, diphtheroid rods ...
A class of arthropods in the subphylum Chelicerata, consisting of spiders, scorpions, harvestmen, mites, ticks, and allies. [G. arachne, spider]
Systemic poisoning following the bite of a spider (especially of the black widow).
- necrotic a. a. caused by spiders belonging to the genus Loxosceles; cutaneous necrosis ...
Long spider-like fingers and toes, a frequent finding in Marfan syndrome, a heritable disorder of connective tissue. "Arachnodactyly" is derived from the Greek "arachne" ...
SYN: a. mater. [G. arachne, spider, cobweb, + eidos, resemblance]
- a. of brain SYN: cranial a. mater.
- cranial a. mater [TA] that portion of the a. that lies within the ...
Relating to the arachnoid membrane, or arachnoidea.
arachnoidea mater, arachnoides
SYN: arachnoid mater. [Mod. L. arachnoideus fr. G. arachne, spider, + eidos, resemblance]
- a. spinalis [TA] SYN: spinal arachnoid mater.
In anatomy, a treelike structure with branchings. [L. tree]
- a. vitae [TA] the arborescent appearance of gray and white matter in sagittal sections of the cerebellum.
- a. ...
1. The terminal branching of nerve fibers or blood vessel s in a branching treelike pattern. 2. The branched pattern formed under certain conditions by a dried smear of ...
To spread in a treelike branching pattern.
Denoting a colony of protozoa, each of which remains attached to another cell or to the main stem at one point, forming a branching or dendritic figure. [L. arbor, tree, + G. ...
What's in a name? Although 'arbor' sounds as if it should have something to do with trees, it doesnt. It comes from the first 2 letters of arthropod + the first 3 letters ...
1. Antibiotics are not effective for treatment and no effective antiviral drugs have yet been discovered for the arboviruses. Treatment is supportive, attempting to deal with ...
A class of viruses transmitted to humans by arthropods such as mosquitoes and ticks. The first two letters of the words arthropod' and borne, make up the 'arbo' that now ...
Abbreviation for AIDS-related complex.
1. A curved line or segment of a circle. 2. Continuous luminous passage of an electric current in a gas or vacuum between two or more separated carbon or other electrodes. [L. ...
An anatomic structure or structures (especially a blood vessel) taking the form of a series of arches. [L. arcus, arc, bow]
- anomalous mitral a. short chordae tendineae ...
A genus of nonmotile, facultatively anaerobic bacteria containing Gram-positive slender irregular rods, sometimes showing clubbed ends that may be in V formation with no ...
Any structure resembling a bent bow or an a.; an arc. In anatomy, any vaulted or archlike structure. See arcus. SYN: arcus [TA]. [thru O. Fr. fr. L. arcus, bow]
The aortic arch is the second section of the aorta, the largest artery in the body. The aorta arises from the left ventricle of the heart and first goes up, then bends, and goes ...
The bone that forms the prominence of the cheek. The zygomatic bone is also known as the zygoma, the zygomatic arch, malar bone, yoke bone. The word "zygomatic" comes from ...
arch-, arche-, archi-
Combining forms meaning primitive or ancestral; also first, chief, extreme. [G. arche, origin, beginning, + -o-]
A unique group of microorganisms classified as bacteria (Archaeobacteria) but genetically and metabolically different from all other known bacteria. They appear to be living ...
The study of the past using the techniques of molecular genetics. The application of genetics to archeology. The term "archaeogenetics" was coined in the 1990s by the archeologist ...
Term first used by Valentine and later by Paracelsus and van Helmont to denote a spirit that presided over and governed bodily processes. SYN: archeus. [L. fr. G. archaios, ...
Ancient; old; in jungian psychology, denoting the ancestral past of mental processes. [G. archaikos, ancient]
LaSalle, U.S. neurologist, 1879–1940. See Meyer-A. loop.
SYN: primitive gut. [G. arche, beginning, + enteron, intestine]
Denoting a low and primitive type of motor nerve mechanism, such as is found in the peripheral and the ganglionic nervous systems. Cf.:neokinetic, paleokinetic. [G. archaios, ...
1. A primitive structural plan from which various modifications have evolved. 2. In jungian psychology, structural manifestation of the collective unconscious. SYN: imago (2). ...
The small, phylogenetically oldest portion of the cerebellum, sometimes called vestibulocerebellum because its afferents arise primarily from the vestibular ganglion and nuclei; ...
1. Typically, the phylogenetically older parts of the cerebral cortex. 2. More specifically, the cortex forming the hippocampus. SEE ALSO: allocortex, cerebral cortex. SYN: ...
A violet dye from the lichens Rocella tinctoria and R. fuciformis. SYN: orchella, orchil, roccellin.
A device consisting of a wire conforming to the alveolar or dental arch, used as an anchorage in correcting irregularities in the position of the teeth. SYN: arch wire.
A genus of bacteria in the family Campylobacteraceae that are Gram-negative, aerotolerant, and able to grow at 15° C. The type strain is A. butzleri.
- A. butzleri a bacterial ...
A narrowing, contraction, stricture, or coarctation. [L. arto (improp. arcto), pp. -atus, to tighten]
Denoting a form that is arched or has the shape of a bow. SYN: arcate, arciform. [L. arcuatus, bowed]
SYN: arch. [L. a bow]
- a. adiposus SYN: a. senilis.
- a. alveolaris mandibulae [TA] SYN: alveolar arch of mandible.
- a. alveolaris maxillae [TA] SYN: alveolar arch of maxilla.
A cloudy opaque arc or circle around the edge of the eye, often seen in the eye of the elderly.
Acronym that stands for a disorder known as Adult Respiratory Distress or Acute Respiratory Distress. Also referred to as ARDS (ARD Syndrome). In ARD there is respiratory ...
Old term for a hot or burning sensation. [L. fire, heat]
Abbreviation for adult respiratory distress syndrome.
1. [TA] Any circumscribed surface or space. 2. All of the part supplied by a given artery or nerve. 3. A part of an organ having a special function, as the motor a. of the ...
A genus of palms of India and the Malay Archipelago. A species, A. catechu, furnishes a. nuts, or betel nut s, which contain arecoline and 15% red tannin, are chewed in the ...
A crystalline alkaloid resembling betaine, derived from the betel nut. SYN: arecaine.
A colorless oily alkaloid from the betel nut.
Absence of neurologic reflexes such as the knee jerk reaction.
* * *
Absence of reflexes.
- detrusor a. a failure of the detrusor muscle to have a reflex contraction even ...
Sandy; of sandlike consistency. [L. arena, sand]
A family of over 15 RNA viruses, many of which are natural parasites of rodents, that includes lymphocytic choriomeningitis virus, Lassa virus, and the Tacaribe virus complex. ...
A genus in the family Arenaviridae that is associated with lymphocytic choriomeningitis and a number of hemorrhagic fevers.
1. The small darkened area around the nipple of the breast. 2. The colored part of the iris around the pupil of the eye. 3. Any small space in a tissue.
* * *
1. [NA] Any small ...
SYN: hydrometer. [G. araios, thin, + G. metron, measure]
Symbol for arginine or its mono- or diradical.
A genus of soft ticks of the family Argasidae, some species of which usually infest birds but may attack humans.
- A. reflexus the pigeon tick, a species that may cause a ...
Common name for members of the family Argasidae.
Family of ticks (superfamily Ixodoidea, order Acarina), the soft ticks, so called because of their wrinkled, leathery, tuberculated appearance that fills out when the tick is ...
Pertaining to cells or tissue elements that reduce silver ions in solution, thereby becoming stained brown or black. [L. argentum, silver, + affinitas, affinity]
A tumor which secretes large amounts of the hormone serotonin. Argentaffinoma is also called carcinoid tumor. The tumor usually arises in the gastrointestinal tract, anywhere ...
Impregnation with a silver salt. SEE ALSO: argyria. [L. argentum, silver]
1. Relating to silver. SYN: argyric (1). 2. Denoting a chemical compound containing silver as the rare dication (Ag2+).
Relating to, resembling, or containing silver.
Denoting a chemical compound containing silver as a singly charged (Ag+) ion. The vast majority of silver compounds contain the a. ion; where the ionic state of silver is not ...
An enzyme of the liver that catalyzes the hydrolysis of l-arginine to l-ornithine and urea; a key enzyme of the urea cycle. A deficiency of a. leads to arginemia. SYN: canavanase.
An amino acid, one of the 20 amino acids that serve as the building blocks in protein. Arginine is not an "essential" amino acid. (It is not essential to the diet, but can be made ...
An enzyme cleaving l-argininosuccinate nonhydrolytically to l-arginine and fumarate; a deficiency of this enzyme leads to argininosuccinoaciduria; a key step in the urea cycle. ...
Formed as an intermediate in the conversion of l-citrulline to l-arginine in the urea cycle.
A disorder of urea cycle due to a deficiency of argininosuccinate lyase; characterized by physical and mental retardation, epilepsy, ataxia, liver disease, friable, tufted hair, ...
The aminoacyl radical of arginine.
A gaseous element, atomic no. 18, atomic wt. 39.948, present in the dry atmosphere in the proportion of about 0.94%; one of the noble gases. [G. ntr. of argos, lazy, inactive, ...
A slate-gray or bluish discoloration of the skin and deep tissues, due to the deposit of insoluble albuminate of silver, occurring after the medicinal administration for a ...
1. SYN: argentic (1). 2. Relating to argyria.
Pertaining to tissue elements that are capable of impregnation with silver ions and being made visible after an external reducing agent is used. SYN: argentophil, argentophile. ...
Congenital absence of the nose. SYN: arrhinia.
We do not usually give a misspelling but this is a frequent misspelling of arrhythmia (with two r's), meaning an abnormal heart rhythm. In an arrhythmia the heartbeats may be ...
Javier, Peruvian pathologist, *1924. See Arias- Stella effect, Arias- Stella phenomenon, Arias- Stella reaction.
Properly hyporiboflavinosis : a nutritional condition produced by a deficiency of riboflavin in the diet, characterized by cheilosis and magenta tongue and usually associated ...
A Chinese herb that is injurious to the kidney and is also associated with an increased risk of cancer of the urinary system. Aristolochia can cause kidney failure requiring renal ...
Of Stagira, Greek philosopher and scientist, 384–322 B.C. See A. anomaly, aristotelian method.
A morbid impulse to count. [G. arithmeo, to count, fr. arithmos, number, + mania, madness]
Former name for Salmonella enterica, subspecies arizonae.
- A. hinshawii former name for Salmonella enterica subsp. arizonae.
Carl Ferdinand von, Austrian ophthalmologist, 1812–1887. See A. operation, A. sinus.
In popular usage, the arm extends from the shoulder to the hand. However, in medical terminology, the arm refers to the upper extremity extending from the shoulder only to the ...
All the therapeutic means available to the health practitioner for professional practice. [L. an arsenal, fr. armamenta, implements, tackle, fr. arma, armor, arms]
Luciano, Italian pathologist, 1839–1903. See A.-Ebstein kidney, A.-Ebstein change.
Rarely used term for the physician's library, as part of her or his armamentarium. [L. a closet, chest, fr. arma, armor]
The pork tapeworm, Taenia solium, a worm contracted from undercooked or measly pork, pork infected with the larval forms of the tapeworm. The worm can grow to be 3-6 feet ...
A genus of Pentastomida (order Porocephalida, family Porocephalidae); adults are found in the lungs of reptiles and the young in many mammals, including humans. [O. Fr. armille, ...
Peter, British statistician, (1924-). See A.-Doll model.
Arthur Riley, Canadian physician, *1904. See King-A. unit.
Henry E., British physician.
Acronym for acute retinal necrosis.
Rudolph G., German psychiatrist, 1835–1900. See A. law.
Joseph, German physician, 1873–1956. See A. classification, A. count, A. formula, A. index, A. stages, under stage.
The dried flower heads of A. montana (family Compositae); Obsolete cardiac sedative seldom given internally; used externally for sprains and bruises; formerly widely used as a ...
Julius, German pathologist, 1835–1915. See A. bodies, under body, A.-Chiari deformity, A.-Chiari malformation, A.-Chiari syndrome.
Friedrich, German anatomist, 1803–1890. See ...
An enzyme (actually an enzyme complex) involved in the production of estrogen that acts by catalyzing the conversion of testosterone (an androgen) to estradiol (an estrogen). ...
A drug that inhibits the enzyme aromatase and thus lowers the level of the estrogen, estradiol. Aromatase inhibitors are a class of antiestrogens. Aromatase catalyzes the ...
A form of alternative medicine based on the use of very concentrated "essential" oils from the flowers, leaves, bark, branches, rind or roots of plants with purported healing ...
1. Having an agreeable, somewhat pungent, spicy odor. 2. One of a group of vegetable drugs having a fragrant odor and slightly stimulant properties. 3. See a. compound. [G. ...
aromatic d-amino acid decarboxylase
An enzyme that catalyzes the decarboxylation of l-dopa to dopamine, of l-tryptophan to tryptamine, and of l-hydroxytryptophan to serotonin; important in the biosynthetic ...
A synthetic polyaromatic retinoid derivative of vitamin A. SEE ALSO: retinoid, retinoic acid. [aromatic + retinoid]
The radical of an aromatic acid ( e.g., benzoyl); analogous to acyl, the more general term.
A strong alcoholic liquor distilled from dates, rice, sap of the coconut palm, and other substances. [Ar. sweet juice]
In genetics, an arrayed library consists of (in technical terms) individual primary recombinant clones which are hosted in phage, cosmid, YAC, or another vector that have been ...
SYN: erector. [L. that which raises, fr. ar-rigo, pp. -rectus, to raise up]
A microscopic band of muscle tissue which connects a hair follicle to the dermis. When stimulated, the arrector pili will contract and cause the hair to become more ...
Tiny muscles that act as the hair erector muscles. The arrectores pilorum play a key role in goose bumps, a temporary local change in the skin The chain of events leading to ...
1. To stop, check, or restrain. 2. A stoppage; interference with, or checking of, the regular course of a disease, a symptom, or the performance of a function. 3. Inhibition of ...
Relating to arsenic. [G. arrhenikon (var.), arsenic]
Svante, Swedish chemist and Nobel laureate, 1859–1927. See A. doctrine, A. equation, A. law, A.-Madsen theory.
SYN: Sertoli-Leydig cell tumor. [G. arrhen, male, + blastos, germ, + -oma, tumor]
SYN: arhinia. [G. a- priv. + rhis (rhin-), nose]
An abnormal heart rhythm. In an arrhythmia the heartbeats may be too slow, too rapid, too irregular, or too early. Rapid arrhythmias (greater than 100 beats per minute) are called ...
The normal increase in heart rate that occurs during inspiration (when you breathe in). This is a natural response and is more accentuated in children than adults. The "sinus" ...
Abnormal heart rhythm due to electrical disturbances in the atria (the upper chambers of the heart) or the AV node "relay station", leading to fast heart beats. ...
Abnormal rapid heart rhythms (arrhythmias) that originate in the lower chambers of the heart (the ventricles). Ventricular arrhythmias include ventricular tachycardia and ...
Marked by loss of rhythm; pertaining to arrhythmia.
Capable of inducing cardiac arrhythmias. [G. a- priv. + rhythmos, rhythm, + -gen, production]
The rhizome of Maranta arundinacea, a plant of tropical America, which is the source of a form of starch formerly used as a dietary supplement.
Count Hermenegildo, Spanish ophthalmologist, 1886–1972. See A. forceps.
Formerly used as an antisyphilitic agent.
Chronic arsenical poisoning. SYN: arsenicalism.
A metallic element that forms a number of poisonous compounds, arsenic is found in nature at low levels mostly in compounds with oxygen, chlorine, and sulfur. These are called ...
Resistant to the poisonous action of arsenic; denoting especially spirochetes and other protozoan parasites, which acquire resistance after repeated administration of the drug.
Denoting the element a. or one of its compounds, especially a. acid.
1. A drug or agent, the effect of which depends on its arsenic content. 2. Denoting or containing arsenic.
A compound of arsenic with a metal or other positively charged atoms or groups in which the arsenic is not bound to any atoms of oxygen. SYN: arseniuret.
1. Denoting a compound of arsenic with a valence of +3. 2. Arsenic (adj.).
Oxidation products in the body of arsphenamines; believed to be the agents active against spirochetes.
A cell and blood poison, many organic derivatives of which have been used in chemical warfare. SYN: arsenic trihydride, arseniureted hydrogen, arsenous hydride.
A derivative of arsenic acid by replacement of a hydroxyl group by an organic radical.
The positively charged ion, AsH4+; analogous to the ammonium ion, NH4+.
Formerly used in the treatment of syphilis, yaws, and some other diseases of protozoan origin, after neutralization with NaOH. The synthesis of a. in 1907 and the demonstration ...
ART (antiretroviral therapy)
Treatment that suppresses or stops a retrovirus. One of the retrovirus is the human immunodeficiency virus (HIV) that causes AIDS. Retroviruses are so named because they carry ...
Semisynthetic derivative of artemisinin used in the treatment of cerebral malaria.