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Medical Dictionary


eutrophy (u′tro-fe)
SYN: eutrophia.

euvolia (u-vo′le-a)
Normal water content or volume of a given compartment; e.g., extracellular e..

eV, ev
Abbreviation for electron-volt.

evacuant (e-vak′u-ant)
1. Promoting an excretion, especially of the bowels. 2. An agent that increases excretion, especially a cathartic.

evacuate (e-vak′u-at)
To accomplish evacuation. [L. e-vacuo, pp. -vacuatus, to empty out]

evacuation (e-vak-u-a′shun)
1. Removal of material, especially wastes from the bowels by defecation. 2. SYN: stool (2) . 3. Removal of air from a closed vessel; production of a vacuum.

evacuator (e-vak′u-a-tor)
A mechanical evacuant; an instrument for the removal of fluid or small particles from a body cavity, or of impacted feces from the rectum. Ellik e. a special instrument with glass receptacle, latex or plastic bulb, and flexible tubing, used to evacuate tissue fragments, blood clots, or calculi from the urinary bladder.

evagination (e-vaj-i-na′shun)
Protrusion of some part or organ from its normal position. [L. e, out, + vagina, sheath]

Systematic, objective assessment of the relevance, effectiveness, and impact of activities in the light of specified objectives.

evanescent (ev-a-nes′ent)
Of short duration. [L. e, out, + vanesco, to vanish]

Herbert M., U.S. anatomist and physiologist, 1882–1971. See E. blue.

Robert S., U.S. physician, 1912–1974. See E. syndrome.

Evans blue [C.I. 23860]
A diazo dye used for the determination of the blood volume on the basis of the dilution of a standard solution of the dye in the plasma after its intravenous injection; it binds to proteins and is also used as a vital stain for following diffusion through blood vessel walls. SYN: azovan blue.

evaporate (e-vap′or-at)
To cause or undergo evaporation. SYN: volatilize.

evaporation (e-vap-o-ra′shun)
1. A change from liquid to vapor form. 2. Loss of volume of a liquid by conversion into vapor. SYN: volatilization. [L. e, out, + vaporo, to emit vapor]

evasion (e-va′zhun)
The act of escaping, avoiding, or feigning. macular e. SYN: horror fusionis.


eventration (e′ven-tra′shun)
1. Protrusion of omentum and/or intestine through an opening in the abdominal wall. SYN: evisceration (4) . 2. Removal of the contents of the abdominal cavity. [L. e, out, + venter, belly] e. of the diaphragm extreme elevation of a half or part of the diaphragm, which is usually atrophic and abnormally thin.

eversion (e-ver′zhun)
A turning outward, as of the eyelid or foot. [L. e-everto, pp. -versus, to overturn]

evert (e-vert′)
To turn outward. [L. e-verto, to overturn]

eviration (ev-i-ra′shun, e-vi-ra′shun)
1. SYN: emasculation. 2. Loss or absence of the masculine, with acquisition of feminine characteristics; a type of effemination. 3. Delusional belief of a man that he has become a woman. [L. e, out, + vir, man]

evisceration (e-vis-er-a′shun)
1. SYN: exenteration. 2. The process wherein tissue or organs that usually reside within a body cavity are displaced outside that cavity usualy through a traumatic disruption of the wall of the cavity; e.g., e. of bowel. 3. Removal of the contents of the eyeball, leaving the sclera and sometimes the cornea. 4. SYN: eventration (1) . [L. eviscero, to disembowel]

evisceroneurotomy (e-vis′er-o-noo-rot′o-me)
Evisceration of the eye with division of the optic nerve. [L. eviscero, to disembowel, + G. neuron, nerve, + tome, a cutting]

evocation (ev-o-ka′shun, e-vo-ka′shun)
Induction of a particular tissue produced by the action of an evocator during embryogenesis. [L. evoco, pp. evocatus, to call forth, evoke]

evocator (ev′o-ka-ter, -tor)
A factor in the control of morphogenesis in the early embryo.

evolution (ev-o-loo′shun)
1. A continuing process of change from one state, condition or form to another. 2. A progressive distancing between the genotype and the phenotype in a line of descent. 3. The liberation of a gas or heat in the course of a chemical or enzymatic reaction. [L. e-volvo, pp. -volutus, to roll out] biologic e. the doctrine that all forms of animal or plant life have been derived by gradual changes from simpler forms and ultimately unicellular organisms. SYN: organic e.. chemical e. the theory of the process by which life arose from inorganic matter. coincidental e. SYN: concerted e.. concerted e. the ability of two related genes to evolve together as though constituting a single locus. SYN: coincidental e.. convergent e. the evolutionary development of similar structures in two or more species, often widely separated phylogenetically, in response to similarities of environment; for example, the wing-like structures in insects, birds, and flying mammals. darwinian e. the proposition that the phylogeny of all species is wholly ascribable to the combined effects of random variation (mutation) in genotypes of the members of a stock as a result of the operation of undirected accidents with consequences to their phenotypes and the operation of preferential (but by no means certain) survival of those resulting phenotypes most suited to survive in the contemporary environment. The proposed system survives largely because of genetic factors that avidly conserve the ontogeny of the stock. divergent e. the process by which a species or gene product gives rise to two or more different products. emergent e. appearance of a property in a complex system e.g., organism that could have been predicted only with difficulty, or perhaps not at all, from a knowledge and understanding of the individual genotype changes taken separately. organic e. SYN: biologic e.. saltatory e. the theory that e. of a new species from an older one may occur as a large jump, such as a major repatterning of chromosomes, rather than by gradual accumulation of small steps or mutations. Cf.:emergent e.. spontaneous e. the unaided delivery of the fetus from a transverse lie.

evulsion (e-vul′shun)
A forcible pulling out or extraction. Cf.:avulsion. [L. evulsio, fr. e-vello, pp. -vulsus, to pluck out]

William, English physician, 1848–1929. See E. procedure, E. sign.

James, U.S. pathologist, 1866–1943. See E. sarcoma, E. tumor.

James H., pathologist, 1798–1827. See E. sign.

Ewingella (oo′ing-el′ah)
Newly named genus of bacteria (family Enterobacteriaciae) that are usually motile, produce acid but not gas from glucose, use citrate as a carbon source, and do not produce hydrogen sulfide on triple sugar; the type species is E. americana, found in the human respiratory tract and recovered from cases of septicemia, usually in association with polymicrobial sepsis.

Out of, from, away from. [L. and G. out of]

exa- (E)
Prefix used in the SI and metric system to signify a multiple of one quintillion (1018).

exacerbation (eg-zas-er-ba′shun, -ek-sas-)
An increase in the severity of a disease or any of its signs or symptoms. [L. ex- acerbo, pp. -atus, to exasperate, increase, fr. acerbus, sour]

exaltation (eks′al-ta′-shun)
An utterance, discourse, or address conveying a marked level of joy, glee, and happiness.

examination (eg-zam-i-na′shun)
Any investigation or inspection made for the purpose of diagnosis; usually qualified by the method used. cytologic e. microscopic e. of cells, especially for diagnosis of disease. direct wet mount e. microscopic review at low (100×) and high dry (400×) total magnifications of a saline and fresh fecal specimen to detect parasites, including motile protozoan trophozoites. EMG e. 1. needle electrode e. portion of the electrodiagnostic e. (limited sense); 2. synonym for entire electrodiagnostic e., including not only the needle electrode e. (electromyogram proper), but the nerve conduction studies as well (expanded sense). fecal e. microscopic review of direct wet mounts, concentration methods, and permanent stained smears to recover and identify parasites from stool specimens. ova and parasite e. a comprehensive review of a fecal specimen, using direct wet mounts, concentration wet mounts, and permanent stained smears, for the recovery and identification of protozoan and helmintic parasite stages such as trophozoites, cysts, oocysts, spores, eggs, and larvae. Papanicolaou e. Pap test. permanent stained smear e. microscopic review at oil immersion (1000×) magnification of fecal specimens stained with trichrome, iron-hematoxylin, and such stains; primarily used for protozoan trophozoites, cysts, oocysts, and spores. physical e. e. by means such as visual inspection, palpation, percussion, and auscultation to collect information for diagnosis. postmortem e. SYN: autopsy.

examiner (eg-zam′in-er)
One who performs an examination. [L. examino, to weigh, examine] medical e. 1. a physician who examines a person and reports upon that person's physical condition to the company or individual at whose request the examination was made. 2. in states or municipalities where the office of coroner has been abolished, a physician appointed to investigate all cases of sudden, violent, or suspicious death.

exanthem (eg-zan′them)
SYN: exanthema.

exanthema (eg-zan-the′ma)
A skin eruption occurring as a symptom of an acute viral or coccal disease, as in scarlet fever or measles. SYN: exanthem. [G. efflorescence, an eruption, fr. anthos, flower] Boston e. a viral disease resembling e. subitum, with the e., if it develops, appearing after the fever has subsided; it is caused by strain 16 of ECHO virus. [after the city in which an epidemic occurred] epidemic e. SYN: epidemic polyarthritis. keratoid e. a symptom occurring in the secondary stage of yaws: patches of fine, light colored, furfuraceous desquamation, scattered irregularly over limbs and trunk. e. subitum a disease of infants and young children caused by herpesvirus-6, marked by sudden onset with fever lasting several days (sometimes with convulsions) and followed by a fine macular (sometimes maculopapular) rash that appears within a few hours to a day after the fever has subsided. SYN: Dukes disease, fourth disease, pseudorubella, roseola infantilis, roseola infantum, sixth disease.

exanthematous (eg-zan-them′a-tus)
Relating to an exanthema.

exanthesis (eg-zan-the′sis)
1. A rash or exanthem. 2. The coming out of a rash or eruption. [G.] e. arthrosia SYN: dengue.

exanthrope (ek′zan-throp)
An external cause of disease, one not originating in the body. [G. ex, out of, + anthropos, man]

exanthropic (ek-zan-throp′ik)
Originating outside of the human body.

exarteritis (eks-ar-ter-i′tis)
SYN: periarteritis.

excalation (eks-ka-la′shun)
Absence, suppression, or failure of development of one of a series of structures, as of a digit or vertebra. [G. ex, from, + chalao, to abate, release]

excavatio (eks-ka-va′she-o)
SYN: excavation (1) . [L. fr. ex-cavo, pp. -cavatus, to hollow out, fr. ex, out, + cavus, hollow] e. disci [TA] SYN: depression of optic disk. e. papillae SYN: depression of optic disk. e. rectouterina [TA] SYN: rectouterine pouch. e. rectovesicalis [TA] SYN: rectovesical pouch. e. vesicouterina [TA] SYN: vesicouterine pouch.

excavation (eks-ka-va′shun)
1. A natural cavity, pouch, or recess; a sunken or depressed area. SYN: depression (2) [TA] , excavatio. 2. A cavity formed artificially or as the result of a pathologic process. atrophic e. an exaggeration of the normal or physiologic cupping of the optic disk caused by atrophy of the optic nerve. glaucomatous e. SYN: glaucomatous cup. e. of optic disk SYN: depression of optic disk. physiologic e. SYN: depression of optic disk.

excavator (eks′ca-va-tor, -tor)
1. An instrument like a large sharp spoon or scoop, used in scraping out pathologic tissue. 2. In dentistry, an instrument, generally a small spoon or curette, for cleaning out and shaping a carious cavity preparatory to filling. hatchet e. hatchet. hoe e. a single-beveled dental e., with the blade at an angle to the axis of the handle and the cutting edge perpendicular to the plane of the angle.

excementosis (ek′se-men-to′sis)
A nodular outgrowth of cementum on the root surface of a tooth.

excentric (ek-sen′trik)
Alternative spelling for eccentric (2, 3).

excess (ek′ses)
That which is more than the usual or specified amount. antibody e. in a precipitation test, the presence of antibody in an amount greater than that required to combine with all of the antigen present. See prozone. antigen e. 1. in a precipitation test, the presence of uncombined antigen above that required to combine with all of the antibody; precipitation may be inhibited because the presence of e. antigen gives rise to soluble antigen-antibody complexes; 2. in vivo the resultant antigen-antibody interaction in such an antigen e. may give rise to immune complexes, which have a potential to induce cellular damage; could be tolerogenic. base e. a measure of metabolic alkalosis, usually predicted from the Siggaard-Andersen nomogram; the amount of strong acid that would have to be added per unit volume of whole blood to titrate it to pH 7.4 while at 37°C and at a carbon dioxide pressure of 40 mm Hg. convergence e. that condition in which an esophoria or esotropia is greater for near vision than for far vision. negative base e. a measure of metabolic acidosis, usually predicted from the Siggaard-Andersen nomogram; the amount of strong alkali that would have to be added per unit volume of whole blood to titrate it to pH 7.4 while at 37°C and at a carbon dioxide pressure of 40 mm Hg.

exchange (eks-chanj′)
To substitute one thing for another, or the act of such substitution. sister chromatid e. the e. during mitosis of homologous genetic material between sister chromatids; increased as a result of inordinate chromosomal fragility due to genetic or environmental factors. See recombination.

excipient (ek-sip′e-ent)
A more or less inert substance added in a prescription as a diluent or vehicle or to give form or consistency when the remedy is given in pill form; e.g., simple syrup, vegetable gums, aromatic powder, honey, and various elixirs. [L. excipiens; pres. p. of ex- cipio, to take out]

excise (ek-siz′)
To cut out. SEE ALSO: resect.

excision (ek-sizh′un)
1. The act of cutting out; the surgical removal of part or all of a structure or organ. SYN: resection (3) . 2. In molecular biology, a recombination event in which a genetic element is removed. SYN: exeresis. [L. excido, to cut out] loop e. a diagnostic and therapeutic gynecological surgical technique for removing dysplastic cells from the cervix. SYN: loop electrosurgical e. procedure, loop resection.In this office procedure, a small wire loop is used to excise visible zones of abnormal epithelium from the uterine cervix. Like cautery, cryosurgery, and CO2 laser procedures, loop e. is a simple and inexpensive way of removing dyplastic cells. Unlike these procedures, it provides a specimen so that the lesion can be studied histologically and the completeness of its removal assessed. The cervix is first prepared with acetic acid and iodine solutions to enhance the demarcation of abnormal areas. Under local anesthesia and with colposcopic visualization, lesions are quickly undercut with a disposable loop electrode. The risk of complications (bleeding, severe postoperative pain, infection, cervical stenosis) is low. The success rate of the loop electrosurgical e. procedure, as defined by the absence of cytologic, histologic, or colposcopic evidence of abnormality 4–48 months after therapy, is 80–90%. Although loop e. does not cure human papilloma virus (HPV) infection, it offers excellent prognosis in HPV-induced dysplasias by removing transformation zone epithelium, which is most susceptible to such changes. The procedure is not appropriate for severe dysplasia or carcinoma in situ, which are treated by cervical conization.

excitability (ek-si′ta-bil′i-te)
Having the capability of being excitable. supranormal e. at the end of phase three of the cardiac action potential, the successful stimulation threshold falls below ( i.e., less negative than) the level necessary to produce excitation during the rest of the phase of diastole, so that an ordinary subthreshold stimulus becomes effective. Cf.:supranormal conduction.

excitable (ek-si′ta-bl)
1. Capable of quick response to a stimulus; having potentiality for emotional arousal. Cf.:irritable. 2. In neurophysiology, referring to a tissue, cell, or membrane capable of undergoing excitation in response to an adequate stimulus.

excitant (ek-si′tant)
SYN: stimulant. [L. excito, pp. -atus, pres. p. -ans, to arouse]

excitation (ek-si-ta′shun)
1. The act of increasing the rapidity or intensity of the physical or mental processes. 2. In neurophysiology, the complete all-or-none response of a nerve or muscle to an adequate stimulus, ordinarily including propagation of e. along the membranes of the cell or cells involved. SEE ALSO: stimulation. anomalous atrioventricular e. ectopic atrial beat conducted to the ventricle.

excitatory (ek-si′ta-to-re)
Tending to produce excitation.

excitement (ek-sit′ment)
An emotional state sometimes characterized by its potential for impulsive or poorly controlled activity. catatonic e. an excited catatonic state seen in one of the schizophrenic disorders. See catatonia. manic e. an excited mental state seen in a bipolar (manic-depressive) disorder characterized by hyperactivity, talkativeness, flight of ideas, pressured speech, grandiosity, and, occasionally, grandiose delusions. See mania, manic-depressive. SYN: acute mania.

excitoglandular (ek-si′to-glan′du-lar)
Increasing the secretory activity of a gland.

excitometabolic (ek-si′to-met-a-bol′ik)
Increasing the activity of the metabolic processes.

excitomotor (ek-si′to-mo′ter)
Causing or increasing the rapidity of motion. SYN: centrokinetic (2) .

excitomuscular (ek-si′to-mus′ku-lar)
Causing muscular activity.


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