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Medical Dictionary


amok (a-mok′)
1. A culture-bound mental disorder originally observed in Malaya in which the subject becomes dangerously maniacal (“running a.”). 2. Colloquialism denoting maniacal, wild, or uncontrolled behavior threatening injury to others. SYN: amuck. [Mayal, amoq, engaged in battle]

amorph (a′morf)
An allele that has no phenotypically recognizable product and therefore its existence can be inferred on molecular evidence only, depending on the subtlety of the means of detection available. SYN: silent allele. [G. a- neg. + morphe, form, shape]

amorphagnosia (a-mor-fag-no′se-a)
Inability to recognize the size and shape of objects. [G. a- priv. + morphe, shape, + gnosis, recognition]

amorphia, amorphism (a-mor′fe-a, -fizm)
Condition of being amorphous (1). [G. a- priv. + morphe, form]

amorphosynthesis (a-mor′fo-sin′the-sis)
Disorder of recognition of the right side of the body in spatial relationships, caused by a lesion of the left parietal lobe. [G. a- priv. + morphe, form, + synthesis]

amorphous (a-mor′fus)
1. Without definite shape or visible differentiation in structure. 2. Not crystallized.

amorphus (a-mor′fus)
A malformed fetus with rudimentary head, limbs, and heart. [G. a- priv. + morphe, form, shape]

amoxapine (a-mok′sa-pen)
A tricyclic antidepressant/anti-psychotic drug; overdose can produce seizures.

amoxicillin (a-mok-si-sil′in)
A semisynthetic penicillin antibiotic with an antimicrobial spectrum similar to that of ampicillin.

Abbreviation for adenosine monophosphate; specifically, the 5′-monophosphate unless modified by a numerical prefix. See adenylic acid.

AMP deaminase
An enzyme hydrolyzing adenylic acid to inosinic acid and NH3. A deficiency of A. in muscles can lead to excess fatigue following exercise. SYN: adenylic acid deaminase.

amperage (am′per-ij)
Strength of electric current. See ampere.

André-Marie, French physicist, 1775–1836. See ampere, statampere, A. postulate.

ampere (A) (am-per)
The practical unit of electrical current; the absolute, practical a. originally was defined as having the value of 110 of the electromagnetic unit (see abampere and coulomb). Present definitions are: 1. The practical unit of electrical current; the absolute, practical a. originally was defined as having the value of 110 of the electromagnetic unit (see abampere and coulomb). 2. Legal definition: the current that, flowing for 1 second, will deposit 1.118 mg of silver from silver nitrate solution. 3. Scientific (SI) definition: the current that, if maintained in two straight parallel conductors of infinite length and of negligible circular cross-sections and placed 1 m apart in a vacuum, produces between them a force of 2 × 10−7 N/m of length. [A. Ampère]

amperometry (am-pe-rom′e-tre)
Determination of any analyte concentration by measurement of the current generated in a suitable chemical reaction.

See amphi-, ampho-.

ampheclexis (am-fe-klek′-sis)
Reciprocal sexual selection, i.e., by both male and female. [G. amphi, two-sided, + eklexis, selection]

amphetamine (am-fet′a-men)
Closely related in its structure and action to ephedrine and other sympathomimetic amines. A psychostimulant substance that can be abused. a. (4-chlorophenoxy)acetate same actions and uses as a. sulfate. a. phosphate same actions and uses as a. sulfate. a. sulfate exerts less vasopressor, cardiac, and bronchial effect than ephedrine, but has a greater central nervous stimulating effect, decreasing the sensation of fatigue; used in the treatment of narcolepsy and certain types of paralysis agitans, and to reduce appetite (temporarily (1–2 weeks) in obesity.

On both sides, surrounding, double; corresponds to L. ambi-. [G. amphi, amphi-, on both sides, about, around]

amphiarthrodial (am′fi-ar-thro′de-al)
Relating to a symphysis (1) (amphiarthrosis).

amphiarthrosis (am′fi-ar-thro′sis)
SYN: symphysis (1) . [amphi- + G. arthrosis, joint]

amphiaster (am-fi-as′ter)
The double-star figure formed by the two astrospheres and their connecting spindle fibers during mitosis. SYN: diaster. [amphi- + G. aster, star]

amphibolic (am′fi-bol′ik)
Referring to reactions or biologic pathways that serve in both biosynthesis and degradation ( i.e., anabolism and catabolism). [amphi- + metabolic]

amphicelous (am-fi-se′lus)
Concave at each end, as the body of a vertebra of a fish. [amphi- + G. koilos, hollow]

amphicentric (am-fi-sen′trik)
Centering at both ends, said of a rete mirabile that begins by the vessel breaking up into a number of branches and ends by the branches joining again to form the same vessel. [amphi- + G. kentron, center]

amphichroic (am-fi-kro′ik)
SYN: amphichromatic.

amphichromatic (am′fi-kro-mat′ik)
Having the property of exhibiting either of two colors; e.g., litmus, an a. pigment that is red in acids and blue in alkalis. SYN: amphichroic. [amphi- + G. chroma, color]

amphicyte (am′fi-sit)
One of the cells located around the bodies of the cerebrospinal and sympathetic ganglionic neurons. SYN: capsule cell. [amphi- + G. kytos, cell]

amphid (am′fid)
In the nervous system of nematodes, a pair of laterally placed minute receptor organs in the cephalic or cervical region. [amphi- + -id]

amphidiploid (am′fi-dip′loid)
Having a complete diploid chromosome set from each parent strain. [amphi + diploid]

amphikaryon (am′fe-kar′e-on)
A diploid nucleus containing two haploid sets of chromosomes. [amphi- + G. karyon, kernel]

amphileukemic (am′fi-loo-ke′mik)
Denoting a leukemic condition that corresponds in degree to the changes in the organ or tissue.

Amphimerus (am-fim′er-us)
A genus of opisthorchid trematodes found in the bile ducts of mammals, birds, and reptiles; probably transmitted by fish. [amphi- + G. meros, segment]

amphimicrobe (am′fi-mi′krob)
A microorganism that is either aerobic or anaerobic, according to the environment.

amphimictic (am′fi-mik′tik)
The ability to freely interbreed and produce fertile offspring. [amphi + G. miktos, joined, mated, fr. mignumi, to mix, mae, + -ia]

amphimixis (am-fi-mik′sis)
1. Union of the paternal and maternal chromatin after impregnation of the ovum. 2. In psychoanalysis, a combination of genital and anal eroticism. [amphi- + G. mixis, mingling]

amphinucleolus (am′fi-noo-kle′o-lus)
A double nucleolus having both basophilic and oxyphilic components. [amphi- + L. nucleolus, dim. of nucleus, kernel]

amphions (am′fi-ons)
SYN: dipolar ions, under ion.

Amphioxus (am-fe-ok′sus)
A genus of small, translucent, fishlike chordates found in warm marine waters. Members are structurally similar to vertebrates in having a notochord, gills, digestive tract, and nerve cord, but they lack paired fins, vertebrae, ribs, or a skull. [amphi- + G. oxys, sharp]

amphipathic (am-fe-path′ik)
Denoting a molecule, such as comprises detergents or wetting agents, that contains groups with characteristically different properties, e.g., both hydrophilic and hydrophobic properties. SYN: amphiphilic, amphiphobic. [amphi- + G. pathos, feeling]

amphiphilic (am-fe-fil′ik)
SYN: amphipathic. [amphi- + G. philos, fond]

amphiphobic (am-fe-fob′ik)
SYN: amphipathic. [amphi- + G. phobos, fear]

amphistome (am-fis′tom)
A common name for any trematode of the genus Paramphistomum. [amphi- + G. stoma, mouth]

amphitrichate, amphitrichous (am-fit′ri-kat, am-fit′ri-kus)
Having a flagellum or flagella at both extremities of a microbial cell; denoting certain microorganisms. [amphi- + G. thrix, hair]

amphitypy (am-fit′i-pe)
Exhibition of the properties characteristic of two types.

amphixenosis (am-fiks-en-o′sis)
A zoonosis maintained in nature by humans and lower animals, e.g., certain staphylococcoses. Cf.:anthropozoonosis, zooanthroponosis. [amphi- + G. xenos, stranger, + G. -osis, condition]

On both sides, surrounding, double. [G. ampho, both]

amphochromatophil, amphochromatophile (am′fo-kro-mat′o-fil, -o-fil)
SYN: amphophil (2) .

amphochromophil, amphochromophile (am-fo-kro′mo-fil, -fil)
SYN: amphophil. [ampho- + G. chroma, color, + philos, fond]

amphocyte (am′fo-sit)
SYN: amphophil (2) .

ampholyte (am′fo-lit)
SYN: amphoteric electrolyte.

amphomycin (am-fo-mi′sin)
An antibiotic substance produced by Streptomyces canus; used topically for skin infections.

amphophil, amphophile (am′fo-fil, -fil)
1. Having an affinity both for acid and for basic dyes. SYN: amphophilic, amphophilous. 2. A cell that stains readily with either acid or basic dyes. SYN: amphochromatophil, amphochromatophile, amphocyte. SYN: amphochromophil, amphochromophile. [ampho- + G. philos, fond]

amphophilic, amphophilous (am-fo-fil′ik, am-fof′i-lus)
SYN: amphophil (1) .

amphoric (am-for′ik)
Denoting the sound heard in percussion and auscultation, resembling the noise made by blowing across the mouth of a bottle. [G. amphora, a jar]

amphoriloquy (am-fo-ril′o-kwe)
Presence of amphoric voice. [G. amphora, a jar, + loquor, to speak]

amphorophony (am-fo-rof′o-ne)
SYN: amphoric voice. [G. amphora, a jar, + phone, voice]

amphoteric (am-fo-tar′ik)
Having two opposite characteristics, especially having the capacity of reacting as either an acid or a base; e.g., Al(OH)3 &tbond; H3AlO3 or an amino acid. [G. amphoteroi (pl.), both, fr. ampho, both]

amphotericin, amphotericin B (am-fo-tar′i-sin)
C46H73NO20;an amphoteric polyene antibiotic prepared from Streptomyces nodosus and available as the sodium deoxycholate complex; also a nephrotoxic antifungal agent used extensively in the treatment of systemic mycoses.

ampicillin (am-pi-si′lin)
An acid-stable semisynthetic penicillin derived from 6-aminopenicillanic acid; it has a broader spectrum of antimicrobial action than penicillin G, inhibits the growth of Gram-positive and Gram-negative bacteria, and is not resistant to penicillinase; also available as a. sodium and a. trihydrate. SYN: d(-)-α-aminobenzylpenicillin.

Abbreviation for L. amplus, large.

amplexus (am-plek′sus)
The pairing of male and female at the time that eggs and sperm are discharged simultaneously in those species, such as frogs, in which fertilization occurs externally. [L. an embrace, fr. amplector, pp. -plexus, to wind around]

amplification (am′pli-fi-ka′shun)
The process of making larger, as in increasing an auditory or visual stimulus to enhance its perception. [L. amplificatio, an enlarging] genetic a. a process for producing an increase in pertinent genetic material, particularly for increasing the proportion of plasmid DNA to that of bacterial DNA. Includes the production of extrachromosomal copies of the genes for RNA. This process is usually seen in malignant cells in humans. linear a. a hearing aid circuit in which all frequencies receive equivalent a..

1. A device that increases the magnification of a microscope. 2. An electronic apparatus that increases the strength of input signals. image a. a device for converting a low light level fluoroscopic image to one that can be seen by the eye in a lighted environment; usually consists of an electronic light a. chained to a television tube. SYN: image intensifier.

amplitude (am′pli-tood)
Largeness; extent; breadth or range. [L. amplitudo, fr. amplus, large] a. of pulse average pulse magnitude, peak magnitude.

ampoule (am′pul)
SYN: ampule.

amprotropine phosphate (am′pro-tro′pen)
An antispasmodic, similar in action to atropine.

ampule, ampul (am′pool)
A hermetically sealed container, usually made of glass, containing a sterile medicinal solution, or powder to be made up in solution, to be used for subcutaneous, intramuscular, or intravenous injection. SYN: ampoule. [L. ampulla]

ampulla, gen. and pl. ampullae (am-pul′la, -e) [TA]
A saccular dilation of a canal or duct. [L. a two-handled bottle] biliaropancreatic a. hepatopancreatic a.. a. biliaropancreatica hepatopancreatic a.. bony ampullae of semicircular canals [TA] a circumscribed dilation of one extremity of each of the three bony semicircular canals, anterior, posterior, and lateral; each contains a membranous a. of the semicircular ducts. SYN: ampullae osseae canalium semicircularium [TA] , osseous a.. a. canaliculi lacrimalis [TA] SYN: a. of lacrimal canaliculus. a. chyli SYN: cisterna chyli. a. of ductus deferens [TA] the dilation of the ductus deferens at the base of the bladder where it approaches its contralateral partner just before it is joined by the duct of the seminal vesicle to form the ejaculatory duct. SYN: a. ductus deferentis [TA] , Henle a.. a. ductus deferentis [TA] SYN: a. of ductus deferens. a. ductus lacrimalis incorrect term for a. of lacrimal canaliculus. duodenal a. 1. SYN: a. of duodenum. 2. SYN: hepatopancreatic a.. a. duodeni [TA] SYN: a. of duodenum. a. of duodenum [TA] the dilated portion of the superior part of the duodenum. SEE ALSO: duodenal cap. SYN: a. duodeni [TA] , bulbus duodeni&star, duodenal a. (1) . a. of gallbladder SYN: Hartmann pouch. Henle a. SYN: a. of ductus deferens. hepatopancreatic a. [TA] the dilation within the major duodenal papilla that normally receives both the (common) bile duct and the main pancreatic duct. SYN: a. hepatopancreatica [TA] , a. biliaropancreatica&star, biliaropancreatic a.&star, a. of Vater, duodenal a. (2) . a. hepatopancreatica [TA] SYN: hepatopancreatic a.. a. of lacrimal canaliculus [TA] a slight dilation at the angle of the lacrimal canaliculus immediately beyond the lacrimal punctum. SYN: a. canaliculi lacrimalis [TA] . a. lactifera SYN: lactiferous sinus. lactiferous a. SYN: lactiferous sinus. a. of lactiferous duct SYN: lactiferous sinus. a. membranacea, pl .ampullae membranaceae ductuum semicircularium [TA] SYN: membranous ampullae of the semicircular ducts. membranous a. SYN: membranous ampullae of the semicircular ducts. membranous ampullae of the semicircular ducts [TA] a nearly spherical enlargement of one end of each of the three semicircular ducts, anterior, posterior, and lateral, where they connect with the utricle. Each contains a neuroepithelial crista ampullaris. SYN: a. membranacea [TA] , membranous a.. a. of milk duct SYN: lactiferous sinus. ampullae osseae canalium semicircularium [TA] SYN: bony ampullae of semicircular canals. osseous a. SYN: bony ampullae of semicircular canals. phrenic a. a physiologic localized dilatation of the distal esophagus, commonly demonstrated by esophagography. rectal a. [TA] a dilated portion of the rectum just above the pelvic diaphragm and proximal to the anal canal. SYN: a. recti [TA] , a. of rectum. a. recti [TA] SYN: rectal a.. a. of rectum SYN: rectal a.. Thoma a. a dilation of the arterial capillary beyond the sheathed artery of the spleen. a. tubae uterinae [TA] SYN: a. of uterine tube. a. of uterine tube [TA] the wide portion of the uterine (fallopian) tube near the fimbriated extremity; it has a complexly folded mucosa with a columnar epithelium of mostly ciliated cells between which are secretory cells. SYN: a. tubae uterinae [TA] . a. of Vater SYN: hepatopancreatic a..


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