Referring to animal forms below the Chordata that do not develop a notochord or chorda.
Permanent contraction of a hollow viscus, such as the stomach or bladder, whereby its capacity is reduced. [G. a- priv. + choreo, to make room, fr. choros, space]
Former name for dermatophytes now placed in the genus Trichophyton or Microsporum. [G. achor, dandruff]
A colorless cell. [G. a- priv. + chroa, color, + kytos, a hollow (cell)]
SYN: achroodextrin. [G. a- priv. + chroma, color, + dextrin]
1. Pallor associated with hippocratic facies, emaciation, and weakness, often heralding a moribund state. SYN: cachectic pallor. 2. SYN: achromia. [G. achromos, ...
A person exhibiting achromatopsia. [G. a- priv. + chroma, color]
1. Colorless. 2. Not staining readily. 3. Refracting light without chromatic aberration. [G. a- priv. + chroma, color]
The weakly staining components of the nucleus, such as the nuclear sap and euchromatin.
1. The quality of being achromatic. 2. The annulment of chromatic aberration by combining glasses of different refractive indexes and different dispersion.
Dissolution of the achromatin of a cell or of its nucleus. SYN: karyoplasmolysis.
1. Not being colored by the histologic or bacteriologic stains. SYN: achromophilic, achromophilous. 2. A cell or tissue that cannot be stained in the usual way. SYN: ...
An hereditary disorder of sight due to a lack of cone vision - that type of vision provided by the cone photoreceptors in the retina. In the normal eye, there are some 6 million ...
This is the compete form of a., characterized by severe deficiency of color perception, associated with nystagmus, photophobia, reduced visual acuity, and “day blindness”; ...
The passage of colorless or very pale urine. [G. a- priv. + chroma, color, + ouron, urine]
1. Hypopigmentation; absence or loss of natural pigmentation of the skin and iris; may be congenital or acquired. SEE ALSO: depigmentation. 2. Lack of capacity to accept stains ...
A Gram-negative bacterial genus of uncertain clinical significance, closely related to members of the Alcaligenes and Ochrobactrum species.
A hypochromic, crescent-shaped erythrocyte, probably resulting from artifactual rupture of a red cell with loss of hemoglobin. SYN: achromacyte, achromatocyte, ghost ...
Absence or loss of pigment in the hair. SEE ALSO: canities. [G. a- priv. + chroma, color, + thrix, hair]
Dextrin of low molecular weight, formed from starch in a stage of the digestion of the latter by amylase; it gives no color reaction with iodine. Cf.:amylodextrin, ...
1. Absence of gastric juice or other digestive secretions. 2. Absence of chyle. [G. a- priv. + chylos, juice]
- a. gastrica diminished or abolished secretion of gastric juice ...
1. Lacking in gastric juice or other digestive secretions. 2. Having no chyle. [G. achylos, without juice]
Needle-shaped or needle-pointed; applied particularly to leaves and crystals. [L. a., small pin]
1. A compound yielding a hydrogen ion in a polar solvent ( e.g., in water); acids form salts by replacing all or part of the ionizable hydrogen with an electropositive element ...
Acid phosphatase is an enzyme that works under acid conditions and is made in the liver, spleen, bone marrow and the prostate gland. Abnormally high serum levels of the enzyme ...
One of the 20 building blocks of protein. The sequence of amino acids in a protein and, hence, the function of that protein are determined by the genetic code in the DNA. Amino ...
One of many molecules that are long chains of lipid-carboxylic acid found in fats and oils and in cell membranes as a component of phospholipids and glycolipids. (Carboxylic acid ...
One of the B vitamins that is a key factor in the synthesis (the making) of nucleic acid (DNA and RNA). A deficiency of folic acid after birth causes a kind of anemia, namely, ...
One of the molecules in the chromosomes of living cells and viruses that plays a central role in the storage and replication of hereditary information and in the expression of ...
Pantothenic acid is vitamin B5, one of the less well known B vitamins, perhaps because it is widely distributed in nature. Pantothenic acid is virtually ubiquitous. It is ...
Acid, trans fatty
An unhealthy substance, also known as trans fat, made through the chemical process of hydrogenation of oils. Hydrogenation solidifies liquid oils and increases the shelf life ...
Acid-base balance refers to the mechanisms the body uses to keep its fluids close to neutral pH (that is, neither basic nor acidic) so that the body can function normally.
A citrate anticoagulant used for the collection and preservation of whole blood. It has largely been replaced by newer anticoagulants (CPD, Adsol) that allow for longer shelf ...
Denoting bacteria that are not decolorized by acid-alcohol after having been stained with dyes such as basic fuchsin; e.g., the mycobacteria and nocardiae.
An increase in the H-ion concentration of the blood or a fall below normal in pH. Individual types of a. are listed by specific name, e.g., isovalericacidemia, aminoacidemia, ...
1. To render acid. 2. To become acid.
1. The state of being acid. 2. The acid content of a fluid.
- total a. (a) an obsolete expression of gastric a., the a. being determined by titration with sodium hydroxide, ...
1. One of the acid-staining cells of the anterior pituitary. 2. A microorganism that grows well in a highly acid medium. [acid + G. philos, fond]
Having an affinity for acid dyes; denoting a cell or tissue element that stains with an acid dye, such as eosin. SYN: oxychromatic.
A pathologic state characterized by an increase in the concentration of hydrogen ions in the arterial blood above the normal level, 40 nmol/L, or pH 7.4; may be caused by an ...
Pertaining to or indicating acidosis.
1. Excretion of an acid urine. 2. Excretion of an abnormal amount of any specified acid. Individual types of a. are prefixed by the specific acid; e.g., aminoaciduria, ...
Pertaining to bacteria that tolerate an acid environment. [acid + L. duro, to endure]
Pertaining to the acinus. SYN: acinic.
A genus of nonmotile, aerobic bacteria (family Moraxellaceae) containing Gram-negative or -variable coccoid or short rods, or cocci, often occurring in pairs. Spores are not ...
SYN: acinous. [L. acinus, grape, + forma, shape]
Resembling an acinus or grape-shaped structure. SYN: aciniform, acinose.
One of the minute grape-shaped secretory portions of an acinous gland. Some authorities use the terms a. and alveolus interchangeably, whereas others differentiate them by the ...
The ending of a tiny airway in the lung, where the alveoli (air sacs) are located. In anatomy, an acinus is a round cluster of cells, usually epithelial cells, that looks ...
The anterior cruciate ligament, one of the ligaments in the knee. The ACL crosses from the underside of the femur (the thigh bone) to the top of the tibia (the bigger bone in ...
A state of continuity between normal and abnormal tissue. SYN: aclasia. [G. a- priv. + klasis, a breaking away, a fragment]
- tarsoepiphyseal a. (tar′-so-ep′i-fiz′e- al) ...
The period of greatest intensity of any symptom, sign, or process. [G. akme, the highest point]
Localized skin inflammation as a result of overactivity of the oil glands at the base of hair follicles. Acne happens when oil (sebaceous) glands come to life around puberty, when ...
This term is actually a misnomer! The appropriate term is simply rosacea which is a chronic skin disease that affects the middle third of the face with persistent redness over ...
The common form of acne seen most often in teenagers or young adults, acne vulgaris is the result of overactive oil glands that become plugged, red, and inflamed. Most ...
Resembling acne. SYN: acneiform.
1. Congenital absence of legs. 2. Atrophy of the muscles of the calves of the legs. [G. a- priv. + kneme, leg]
Abbreviation for American College of Nuclear Medicine.
Abbreviation for American College of Nuclear Physicians.
Juice from the leaves and stems of A. ouabaio (family Apocynaceae), a South African arrow poison containing ouabain. [G. akoke, a point, + antheros, blooming]
Without limbs. [G. a- priv. + kolon, limb]
An iron-containing enzyme catalyzing the dehydration of citric acid to cis-aconitic acid, a reaction of significance in the tricarboxylic acid cycle. SYN: aconitase.
The dried root of Aconitum napellus (family Ranunculaceae), monkshood or wolfsbane; a powerful and rapid-acting poison formerly used as an antipyretic, diuretic, diaphoretic, ...
The exceedingly poisonous active principle (diterpene alkaloid) of Aconitum sp. and Delphinium sp., formerly used as a cardiac sedative and applied externally for neuralgia.
Congenital absence of the pupil of the eye. [G. a- priv. + kore, pupil]
Joseph (José) de, Spanish Jesuit missionary, 1539–1600. See A. disease.
Pertaining to sound, e.g., a. meatus, a. nerve. [Gr. akoustikos]
A cranial nerve concerned with hearing, balance and head position. The acoustic nerve is the 8th cranial nerve. It branches into two parts — a cochlear part integral to hearing ...
1. A benign tumor that may develop on the hearing and balance nerves near the inner ear. The tumor results from an overproduction of Schwann cells — small sheet-like cells ...
1. A benign tumor that may develop on the hearing and balance nerves near the inner ear. The tumor results from an overproduction of Schwann cells — small sheet-like cells ...
Morbid fear of sounds. [G. akoustikos, acoustic, + phobos, fear]
The science concerned with sound. [G. akoustikos, relating to sound]
Abbreviation for acyl carrier protein; American College of Physicians.
Enzyme transferring acetyl from acetyl-CoA to ACP and releasing CoA to begin fatty acid synthesis. SYN: acetyl transacylase.
An enzyme transferring malonyl from malonyl-CoA to ACP and releasing free CoA; a key step in fatty acid synthesis. SYN: malonyl transacylase.
Abbreviation for acrocephalosyndactyly.
Anything that is not present at birth but develops some time later. In medicine, the word "acquired" implies "new" or "added." An acquired condition is "new" in the sense that it ...
The loss of hearing that occurs or develops some time during a person's life but was not present at birth. Acquired deafness contrasts to congenital deafness which is present at ...
A change in a gene or chromosome that occurs in a single cell after the conception of the individual. That change is then transmitted to all cells descended from that cell, ...
In psychology, the empiric demonstration of an increase in the strength of the conditioned response in successive trials of pairing the conditioned and unconditioned stimuli.
Abbreviation for American College of Radiology.
Relating to or affecting the peripheral parts, e.g., limbs, fingers, ears, etc. [G. akron, extremity]
A group of the phylum Chordata whose members possess a notochord, gill slits, and nerve cord but no vertebrae, ribs, or skull; e.g., Amphioxus, tunicates, and acorn worms. [G. ...
Complete or partial absence of a skull; associated with anencephaly. [G. a- priv. + kranion, skull]
Having no cranium; relating to acrania or an acranius.
A malformed fetus exhibiting acrania.
Olaf, Swedish surgeon, 1717–1806. See A. ganglion.
A genus of fungi (family Moniliaceae, order Moniliales) that causes eumycotic mycetoma; three species, A. falciforme, A. kiliense, and A. recifei, produce whitish to yellow ...
An instrument for measuring very minute objects. [G. akribes, exact, + metron, measure]
Sharp, pungent, biting, or irritating. [L. acer (acr-), pungent]
10-Azaanthracene; a dye, dye intermediate, and antiseptic precursor ( 9-aminoacridine, acriflavine, proflavine hemisulfate) derived from coal tar and irritating to skin and ...
3,6-bis(dimethylamino)acridine hydrochloride; a basic fluorescent dye useful as a metachromatic stain for nucleic acid s; also used in screening cervical smears for abnormal and ...
A faintly yellow solution with strong bluish-violet fluorescence; used as a topical antiseptic and as a fluorescent stain in histology. SYN: 5-aminoacridine hydrochloride, ...
An acridine dye, a mixture of 3,6-diamino-10-methylacridinium chloride and 3,6-diaminoacridine; formerly used as a topical and urinary antiseptic, and used as one of Kasten ...
In ancient humoral pathology, a sharp, pungent, disease-provoking humor. [L. pungency]
The quality of being intensely irritant, biting, or pungent. [L. acrimonia, pungency]
Rarely used term for: 1. Not critical; marked by no crisis; denoting diseases terminating by lysis. 2. Indeterminate, especially concerning prognosis. [G. a- priv. + kritikos, ...
Combining form meaning: 1. Extremity, tip, end, peak, topmost. 2. Extreme. [G. akron, highest point, extremity; akros, topmost, outermost, inmost, extreme, tip]
Loss or impairment of the sensory recognition of a limb. Absence of acrognosis.
Anesthesia of one or more of the extremities. [acro- + G. an- priv. + aisthesis sensation]
Inflammation of the joints of the hands or feet. [acro- + G. arthron, joint, + -itis]
Impaired digital circulation, possibly a mild form of Raynaud disease, marked by a purplish or waxy white color of the fingers, with subnormal local temperature and ...
Ataxia affecting the distal portion of the extremities, i.e., hands and fingers, feet, and toes. Cf.:proximoataxia. [acro- + ataxia]
Component of the developing spermatid composed of numerous Golgi elements; it contains the proacrosomal granules. [acro- + G. blastos, germ]
Type of craniosynostosis with premature closure of the coronal suture, resulting in abnormally short anteroposterior diameter of the skull. [acro- + G. brachys, short, + ...
Having the centromere close to one end; said of normal chromosomes 13–15 and 21–22. [acro- + G. kentron, center]
A chromosome (one of the microscopically visible carriers of the genetic material DNA) with its centromere (the “waist” of the chromosome) located quite near one end of the ...
A group of congenital syndromes characterized by abnormal skull shape due to craniosynostosis, brachydactyly, syndactyly, and preaxial polydactyly of hands and/or feet; ...
An inherited disorder causing abnormalities of the skull and face and the hands and feet. In acrocephalosyndactyly there is closure too-early of some of the sutures of the skull ...
SYN: oxycephaly. [acro- + G. kephale, head]
A small tag of skin that may have a stalk (a peduncle). An acrochordon may appear on skin anywhere although the favorite locales are the eyelids, neck, armpits (axillae), upper ...
Blueness of the extremities (the hands and feet). Acrocyanosis is typically symmetrical. It is marked by a mottled blue or red discoloration of the skin of the fingers and wrists ...
Inflammation of the skin of the extremities. [acro- + G. derma, skin, + -itis, inflammation]
- a. chronica atrophicans a gradually progressive late skin manifestation of Lyme ...
An historic model for the therapy of genetic disease. In an era (the 1950s) when inherited disorders were usually seen as hopeless, this progressive hereditary (autosomal ...
Any cutaneous affection involving the more distal portions of the extremities. [acro- + G. derma, skin, + -osis, condition]
Tooth attachment in some lower vertebrates (mainly fish) in which the teeth rest on the edge of the jaw bone rather than in sockets or alveoli. [acro- + G. odous, tooth]
1. Pain in peripheral or acral parts of the body. 2. A syndrome caused almost exclusively in the past by mercury poisoning : in children, characterized by erythema of the ...
Abnormal and unpleasant sensations in the peripheral portions of the extremities. [acro- + dysesthesia]
A disorder in which the hands and feet are short with stubby fingers and toes. Growth retardation is progressive. Mental retardation and marked nasal hypoplasia are also present; ...
1. An extreme degree of hyperesthesia. 2. Hyperesthesia of one or more of the extremities. [acro- + G. aisthesis, sensation]
Denoting conida of fungi produced by the conidiogenous cell at the tip of a conidiophore. [acro- + G. genos, birth]
Reduction or loss of subcutaneous fat and collagen of the hands and feet, giving the appearance of premature aging. [acro- + G. geron, old]
Cenesthesia, or normal sensory perception, of the extremities. [acro- + G. gnosis, knowledge]
An autosomal dominant papular keratosis of the palms and soles, with disorganization of dermal elastic fibers; a similar, but acquired, condition may result from actinic ...
Overgrowth of the horny layer of the skin, usually nodular configurations, of the dorsum of the fingers and toes, and occasionally on the rim of the ear and tip of the nose. ...
Pertaining to or characterized by acromegaly.
Gigantism in which the facial features, disproportionate enlargement of the extremities, and other signs of acromegaly are prominent. [acro- + G. megas, great, + gigas, giant]
Rarely used term for a condition in which body proportions resemble those of acromegaly.
Condition due to the production of too much growth hormone by the pituitary gland after the end of adolescence. When there is secretion of too much growth hormone before the end ...
See erythromelalgia. [acro- + G. melos, limb, + algos, pain]
Affecting the terminal part of a limb. [acro- + G. melos, limb]
SYN: acromesomelic dwarfism. SYN: acromelia. [acro- + G. melos, limb, + ia, condition]
Abnormal growth of the extremities resulting in malformation. [acro- + G. meta, beyond, + genesis, origin]
The antithesis of acromegaly; a condition in which the bones of the face and extremities are small and delicate; possibly due to a deficiency of somatotropin. [acro- + G. ...
Relating to the acromion and the clavicle; denoting the articulation and ligaments between the clavicle and the acromion of the scapula. SYN: scapuloclavicular (1).
The acromioclavicular (AC) joint is located between the acromion (a projection of the scapula that forms the point of the shoulder) and the clavicle (the collar bone). This is ...
The projection of the scapula (the shoulder blade) that forms the point of the shoulder. The acromion is part of the scapula. It protrudes laterally (away from the midline) and ...
A surgical reshaping of the acromion, frequently performed to remedy compression of the supraspinatus portion of the rotator cuff of the shoulder joint between the acromion ...
Abnormal projection of the umbilicus. [acro- + G. omphalos, umbilicus]
Myotonia affecting the extremities only, resulting in spastic deformity of the hand or foot. SYN: acromyotonus. [acro- + G. mys, muscle, + tonos, tension]
Congenital condition manifested by palmar and plantar ulcerating lesions with osteolysis involving distal phalanges of the fingers and toes. Acquired acro-osteolysis has been ...
SYN: hereditary clubbing. [acro- + G. pachys, thick]
SYN: pachydermoperiostosis. [acro- + G. pachys, thick, + derma, skin]
1. Paresthesia of one or more of the extremities. 2. Nocturnal paresthesia involving the hands, most often of middle-aged women; formerly attributed to a lesion in the ...
1. In a direction toward the summit. 2. Produced successively toward the apex, with the youngest conidium formed at the tip and the oldest at the base of a chain of conidia; ...
An abnormally excessive and persistent fear of heights. Sufferers experience severe anxiety even though they usually realize that, as a rule, heights pose no real threat to them. ...
Punctate and reticulate hyperpigmentation of the dorsal surfaces of the fingers and toes beginning in early childhood and usually increasing with age; more common in Asian ...
Denoting spores developing at the tip and along the sides of fungal hyphae.
Pustular eruptions of the hands and feet, often a form of psoriasis. [acro- + pustulosis]
- infantile a. a cyclically recurrent vesicopustular and crusting pruritic eruption, ...
SYN: acrosclerosis. [acro- + G. skleros, hard, + derma, skin]
Stiffness and tightness of the skin of the fingers, with atrophy of the soft tissue and osteoporosis of the distal phalanges of the hands and feet; a limited form of progressive ...
A serine proteinase in spermatozoa similar in specificity to trypsin.
A caplike organelle or saccule derived from the golgi that surrounds the anterior two-thirds of the nucleus of a sperm cell. Within this cap are enzymes that are thought to ...
A lipoglycoprotein complex present in the acrosomal cap.
A tumor of the distal dermal segment of a sweat gland. [scro- + G. speira, coil, + -oma, tumor]
- eccrine a. SYN: clear cell hidradenoma.
Relating to the extreme peripheral or apical parts, such as the tips of fingers and toes, the end of the nose. [G. akroterion, the topmost point]
Former name for species now placed in the genus Rhinocladiella or Fonsecaea. [see a.]
In fungi, a type of spore formation characteristic of the genus Fonsecaea, in which conidia are formed along the ends and sides of irregular club-shaped conidiophores. [acro- + ...
1. Marked by great weakness or absence of the pulse; pulseless. [G. a- priv. + krotos, a striking] 2. Obsolete term relating to the surface of the body, especially the cutaneous ...
Absence or imperceptibility of the pulse. [G. a- priv. + krotos, a striking]
Pain, paresthesia, sensory loss, and trophic changes affecting the distal extremities, usually the feet, that can follow prolonged exposure of the limbs to cold and moisture. ...
Trophoneurosis of one or more of the extremities. [acro- + G. trophe, nourishment, + neuron, nerve, + -osis, condition]
A salt or ester of acrylic acid.
Denoting certain synthetic plastic resins derived from a. acid. SEE ALSO: a. resin.
A series of unsaturated aliphatic acids of the general formula R=CH—COOH; the prototype, acrylic acid (R = CH2) or 2-propenoic acid, is derived from propionic acid by ...
ACS (American Cancer Society)
A "nationwide community-based voluntary health organization dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives and diminishing suffering ...
ACS (American College of Surgeons)
The American College of Surgeons was formed in 1913 under the aegis of Dr. John Miller Turpin Finney "to elevate the standard of surgery, to establish a standard of competency ...
Abbreviation for activated clotting time.
Abbreviation for adrenocorticotropic hormone.
- big A. a form of A., produced by certain tumors, which is a larger and more acidic peptide molecule than little A., but is not ...
One of the protein components into which actomyosin can be split; it can exist in a fibrous form (F-a.) or a globular form (G-a.).
- F-a. the association of G-a. subunits into a ...
An overt act or set of actions that provides an emotional outlet for the expression of emotional conflicts (usually unconscious).
Relating to the chemically active rays of the electromagnetic spectrum. [G. aktis (aktin-), a ray]
A small rough spot on skin chronically exposed to the sun, precancerous, can develop into a skin cancer called squamous cell carcinoma, a process that typically takes years. ...
Those elements with atomic numbers 89 to 103, corresponding to the lanthanides in the Periodic Table. SYN: actinide elements. [actinium, first element of the series]
An element, atomic no. 89, atomic wt. 227.05; it possesses no stable isotopes and exists in nature only as a disintegration product of uranium and thorium. [G. aktis, a ray]
Combining form meaning a ray, as of light; applied to any form of radiation or to any structure with radiating parts. SEE ALSO: radio-. [G. aktis, aktinos, a ray of light, a ...
A disease of cattle and swine, occasionally reported in humans, caused by the bacterium Actinobacillus lignieresii. It affects the soft tissues, often the tongue and cervical ...
A genus of very small, nonmotile, nonsporeforming, aerobic, facultatively anaerobic bacteria containing Gram-negative rods interspersed with coccal elements. The metabolism of ...
A red respiratory pigment found in certain forms of Actinia (sea anemones). [ actino- + G. haima, blood]
A genus of aerobic Gram-positive, branching, nonacidfast filamentous bacteria; it may form aerial hyphae and may contain chains of up to 15 spores. [ actino- + Madura, India]
Relating to the mycelium-like filaments of the Actinomycetales.
A genus of slow-growing, nonmotile, nonsporeforming, anaerobic to facultatively anaerobic bacteria (family Actinomycetaceae) containing Gram-positive, irregularly staining ...
A family of nonsporeforming, nonmotile, ordinarily facultatively anaerobic (some species are aerobic and others are anaerobic) bacteria (order Actinomycetales) containing ...
An order of bacteria consisting of moldlike, rod-shaped, clubbed or filamentous forms with decided tendency to true branching, without endospores, but sometimes developing ...
A term used to refer to members of the genus Actinomyces; sometimes improperly used to refer to any member of the family Actinomycetaceae or order Actinomycetales.
A group of peptide antibiotic agents, isolated from several species of Streptomyces (originally Actinomyces), that are active against Gram-positive bacteria, fungi, and ...
A disease primarily of cattle and humans caused by the bacterium Actinomyces bovis in cattle and by A. israelii and Arachnia propionica in humans. These actinomycetes are part ...
A sporozoan order having a double cellular envelope, three polar capsules, and eight spores; parasitic chiefly in segmented worms, such as the common earthworm. [ actino- + G. ...
A virus specific for actinomycetes. [actino(myces) + G. phago, to eat]
A class of Sarcodina having slender pseudopodia with a central axial filament. [ actino- + G. pous, foot]
A phenoxazone derivative that is the chromophore of the actinomycins.
In dermatology, sunlight or ultraviolet light therapy.
1. The performance of any of the vital functions, the manner of such performance, or the result of the same. 2. The exertion of any force or power, physical, chemical, or mental. ...
1. To render active. 2. To make radioactive.
1. The act of rendering active. 2. An increase in the energy content of an atom or molecule, through the raising of temperature, absorption of light photons, etc., which renders ...
1. A substance that renders another substance, or catalyst, active, or that accelerates a process or reaction. 2. The fragment, produced by chemical cleavage of a ...
The active acceleration of a "good" death by use of drugs etc, whether by oneself or with the aid of a doctor. The word " euthanasia" comes from the Greek — "eu" meaning ...
Placental hormone that reaches maximum levels in maternal serum during labor. [active + -in]
Activities of daily living (ADLs)
The things we normally do in daily living including any daily activity we perform for self-care (such as feeding ourselves, bathing, dressing, grooming), work, homemaking, and ...
1. In electroencephalography, the presence of neurogenic electrical energy. 2. In physical chemistry, an ideal concentration for which the law of mass action will apply ...
A measure of the physiological response a drug produces in the body. A less active drug produces less response (and visa versa).
A protein complex composed of actin and myosin; it is the essential contractile substance of muscle fiber, active with MgATP.
- platelet a. the contractile protein of ...
A nematode parasite in the proventriculus and esophagus, and sometimes the intestine, of chickens, turkeys, pheasants, and other birds. [L. acus, needle; Mod. L. spiralis, spiral]
1. Sharpness, clearness, distinctness. 2. Severity. [thr. Fr., fr. L. acuo, pp. acutus, sharpen]
- absolute intensity threshold a. the minimal light that can be seen.
Acuity test, visual
This test measures how well you see at various distances. It is the familiar eye chart test. The eye chart itself — the usual one is called Snellen's chart — is imprinted ...
The clarity or clearness of hearing, a measure of how well a person hears and monitoring the ability to hear. The word " acuity" comes from the Latin "acuitas" = sharpness.
The clarity or clearness of the vision, a measure of how well a person sees. The ability to distinguish details and shapes of objects; also called central vision. The word " ...
Pointed; covered with sharp spines. [L. aculeatus, pointed, fr. acus, needle]
A neutrophil and macrophage motility protein that links to the actin molecule to control filament length.
Pointed; tapering to a point. [L. acumino, pp. -atus, to sharpen]
The study of the use of needles for therapeutic purposes, as in acupuncture. [L. acus, needle, + G. logos, study]
The application of pressure on specific points on the body to control symptoms such as pain or nausea. Similar in concept to acupuncture but without needles.
* * *
The practice of inserting needles into the body to reduce pain or induce anesthesia. More broadly, acupuncture is a family of procedures involving the stimulation of anatomical ...
A person skilled in the practice of acupuncture, who may or may not be credentialed by a national accrediting body.
The ability to perceive sound normally. SYN: normal hearing. [G. akousis, hearing]
Of short duration, rapid and abbreviated in onset, in reference to a disease. “Acute” is a measure of the time scale of a disease and is in contrast to “subacute” and ...
Acute angle-closure glaucoma
Increased pressure in the front chamber (anterior chamber) of the eye due to sudden (acute) blockage of the normal circulation of fluid within the eye. The block takes place at ...
Acute bacterial prostatitis
Inflammation of the prostate gland of sudden (acute) onset due to bacterial infection. The symptoms include chills, fever, pain in the lower back and genital area, body aches, ...
Acute coronary syndromes
A spectrum of conditions involving chest discomfort or other symptoms caused by lack of oxygen to the heart muscle (the myocardium). The unification of these manifestations of ...
A very rapidly progressive infection causing inflammation of the epiglottis (the flap that covers the trachea) and tissues around the epiglottis that may lead to abrupt ...
Acute fatty liver of pregnancy
Liver failure in late pregnancy, usually from unknown cause. Acute fatty liver of pregnancy (AFLP) typically occurs in first-time pregnancies in the last trimester. AFLP causes ...
Acute idiopathic polyneuritis
Also known as the Guillain-Barre syndrome, a disorder characterized by progressive symmetrical paralysis and loss of reflexes, usually beginning in the leg, with in most cases ...
A disease with an abrupt onset and usually a short course.
Acute membranous gingivitis
This is trench mouth, a progressive painful infection with ulceration, swelling and sloughing off of dead tissue from the mouth and throat due to the spread of infection from the ...
Acute mountain sickness (AMS)
Acute mountain sickness (AMS) is the effect on the body of being in a high altitude environment. AMS is common at high altitudes, that is above 8,000 feet (2,440 meters). ...