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Medical Dictionary


  • gas flow
  • unipolar electrocardiogram leads
  • valine
  • valy
  • vanadium
  • ventilation
  • vision or visual acuity
  • volt
  • volume, frequently with subscripts denoting location, chemical species, and/or conditions.
  • volt; initial rate velocity
  • velocity
  • vel [Latin or]
  • venous blood.
  • mixed venous (pulmonary arterial) blood
V gene
a gene that codes genetic information for the variable region of an immunoglobulin

ventricular fibrillation

ventricular tachycardia

volume per volume

alveolar ventilation

tidal volume.

  • venereal disease
  • physiologic dead space
Symbol for carbon dioxide elimination.

Symbol for oxygen consumption.

maximum velocity.

Abbreviation for ventriculoatrial.

Abbreviation for ventriculoatrial conduction.

vaccenic acid (vak-sen′ik)
An unsaturated fatty acid of which both cis and trans isomers are found in butter and other animal fats.

vaccina (vak-sin′a)
SYN: vaccinia.

vaccinal (vak′si-nal)
Relating to vaccine or vaccination.

vaccinate (vak′si-nat)
To administer a vaccine.

vaccination (vak′si-na′shun)
The act of administering a vaccine.

vaccinator (vak′si-na-tor)
1. A person who vaccinates. SYN: vaccinist. 2. A scarifier or other instrument used in vaccination.

vaccine (vak′sen, vak-sen′)
  • Originally, the live v.: (vaccinia, cowpox) virus inoculated in the skin as prophylaxis against smallpox and obtained from the skin of calves inoculated with seed virus. Usage has extended the meaning to include essentially any preparation intended for active immunologic prophylaxis; e.g., preparations of killed microbes of virulent strains or living microbes of attenuated (variant or mutant) strains; or microbial, fungal, plant, protozoal, or metazoan derivatives or products. Method of administration varies according to the v., inoculation being the most common, but ingestion is preferred in some instances and nasal spray is used occasionally. SYN: vaccinum. [L. vaccinus, relating to a cow]
  • adjuvant v.: a v. that contains an adjuvant; the antigen (immunogen) is included in a water-in-oil emulsion (Freund incomplete type adjuvant), or is adsorbed onto an inorganic gel (alum, aluminum hydroxide or phosphate) or mixed with another material to prevent rapid elimination by the host.
  • aqueous v.: a v. having a liquid vehicle ( e.g., physiologic salt solution) as distinguished from an emulsion.
  • attenuated v.: live pathogens that have lost their virulence but are still capable of inducing a protective immune response to the virulent forms of the pathogen, e.g., Sabin polio v..
  • autogenous v.: a v. made from a the patient's own microorganisms.
  • bacillus Calmette-Guérin v.: BCG v..
  • BCG v.: a suspension of an attenuated strain (bacillus Calmette-Guérin) of Mycobacterium tuberculosis, bovine type, which is inoculated into the skin for tuberculosis prophylaxis. SYN: bacillus Calmette-Guérin v., Calmette-Guérin v., tuberculosis v..
  • brucella strain 19 v.: a live bacterial v. prepared from an attenuated variant strain of Brucella abortus (strain 19); used for vaccinating cattle against brucellosis.
  • Calmette-Guérin v.: BCG v..
  • cholera v.: an inactivated suspension of Inaba and Ogawa strains of Vibrio cholerae grown either on agar or in broth and preserved with phenol.
  • crystal violet v.: hog cholera vaccines.
  • diphtheria toxoid, tetanus toxoid, and pertussis v.: (DTP) a v. available in three forms: 1) diphtheria and tetanus toxoids plus pertussis v. (DTP); 2) tetanus and diphtheria toxoids, adult type (Td); and 3) tetanus toxoid (T); used for active immunization against diphtheria, tetanus, and whooping cough.
  • duck embryo origin v.: (DEV) rabies v..
  • Flury strain v.: rabies v., Flury strain egg-passage.
  • foot-and-mouth disease virus vaccines: vaccines either of inactivated virus from infected cattle tongue epithelium or, more recently, of live virus attenuated by embryonated egg or mouse passage and propagated in tissue culture.
  • Haemophilus influenzae type B v.: a conjugate of oligosaccharides of the capsular antigen of H. influenzae type B and diphtheria CRM protein. SYN: Hib v..
  • Haffkine v.: a killed culture of Vibrio cholerae in two strengths, a weaker one for the initial inoculation and a stronger one for the second inoculation 7–10 days after the first
  • a killed plague bacillus (Yersinia pestis) v..
  • hepatitis B v.: originally a formalin-inactivated v. prepared from the surface antigen (HBsAg) of the hepatitis B virus; the antigen was formerly obtained from the plasma of human carriers of the virus; today in the U.S., purified HBsAg is now primarily prepared by recombinant DNA technology and is used almost exclusively for immunization.
  • heterogenous v.: v. that is not autogenous, may be prepared from other species of bacterium.
  • Hib v.: Haemophilus influenzae type B v..
  • high-egg-passage v.:, HEP v. rabies v., Flury strain egg-passage.
  • hog cholera vaccines: vaccines either of virus from blood of infected swine, inactivated with crystal violet, or live virus attenuated in rabbits or tissue culture and frequently used in conjunction with hog cholera virus antiserum.
  • human diploid cell v.: (HDCV) an iodinated virus v. used for protection against rabies v. usually prepared in the human diploid cell WI-38. SYN: human diploid cell rabies v..
  • human diploid cell rabies v.: (HDCV), aka human diploid cell v..
  • inactivated poliovirus v.: (IPV) poliovirus vaccines
  • influenza virus vaccines influenza virus grown in embryonated eggs and inactivated, usually by the addition of formalin; both whole virus and subunit preparations containing hemagglutinins and neuraminidase are used; because of the marked and progressive antigenic variation of the influenza viruses, the strains included are regularly changed following various outbreaks of influenza in order to include most recently isolated epidemic strains of both type A influenza and type B influenza.
  • live v.: v. prepared from living, attenuated organisms.
  • live oral poliovirus v.: poliovirus vaccines
  • low-egg-passage v., LEP v.: rabies v., Flury strain egg-passage.
  • measles, mumps, and rubella v. (MMR): a combination of live attenuated measles, mumps, and rubella viruses in an aqueous suspension; used for immunization against the respective diseases.
  • measles virus v.: v. containing live, attenuated strains of measles virus prepared in chick embryo cell culture. See measles, mumps, and rubella v..
  • multivalent v.: polyvalent v..
  • mumps virus v.: v. containing live, attenuated mumps virus prepared in chick embryo cell cultures. See measles, mumps, and rubella v..
  • oil v.: adjuvant v..
  • oral poliovirus v. (OPV): poliovirus vaccines
  • Pasteur v.: rabies v..
  • pertussis v.: diphtheria toxoid, tetanus toxoid, and pertussis v..
  • plague v.: v. (licensed for use in the U.S.) prepared from cultures of Yersinia pestis, inactivated with formaldehyde, and preserved with 0.5% phenol; injections are made intramuscularly, and booster inoculations are recommended every 6–12 months while individuals remain in an area of risk; live, attenuated bacterial and chemical fraction vaccines are also available.
  • pneumococcal v.: v. comprised of purified capsular polysaccharide antigen from 23 types of Streptococcus pneumoniae (representing those types responsible for most of the reported pneumococcal diseases in the U.S.); some types have been conjugated with protein to make them antigenic for children under 2 years.
  • poliomyelitis vaccines: poliovirus vaccines.
  • poliovirus vaccines: inactivated poliovirus v. (IPV), an aqueous suspension of inactivated strains of poliomyelitis virus (types 1, 2, and 3) used by injection; has largely been replaced by the oral v.; See Salk v.
  • oral poliovirus v.: (OPV), an aqueous suspension of live, attenuated strains of poliomyelitis virus (types 1, 2, and 3) given orally for active immunization against poliomyelitis. See Sabin v., aka poliomyelitis vaccines.
  • polysaccharide conjugated v.: a v. made from the capsular polysaccharide of the microorganism conjugated with a protein such as the Haemophilus influenzae type B v. against meningitis.
  • polyvalent v.: a v. prepared from cultures of two or more strains of the same species or microorganism. SYN: multivalent v..
  • rabies v.: a v. introduced by Pasteur as a method of treatment for the bite of a rabid animal: daily (14–21) injections of virus that increased serially from noninfective to fully infective “fixed” virus were given to render the central nervous system refractory to infection by virulent virus; this v., with but slight modification ( e.g., Semple v.), was used for many years but had the serious defect that the large quantity of heterologous nervous tissue inoculated along with the virus occasionally gave rise to an allergic (immunologic) demyelinization. It was replaced, in the case of humans, by rabies v. of duck embryo origin (DEV), prepared from embryonated duck eggs infected with “fixed” virus and inactivated with β-propiolactone. At the present time DEV has been replaced by either human diploid cell v. (HDCV), which is grown in WI-38 cells or rabies v. adsorbed (RVA), which is grown in fetal Rhesus monkey cells. They both are inactivated and have a low incidence of adverse reactions and require fewer injections.
  • rabies v., Flury strain egg-passage: high-egg-passage (HEP) v.: living Flury strain rabies virus at the 180th to 190th level egg passage (embryonate eggs), used for vaccination of cattle and cats; low-egg-passage (LEP) v.: at the 40th to 50th passage level, containing 103–104 mouse LD50; nonpathogenic in dogs but retains some pathogenicity for cattle and cats.
  • rickettsia v.:, attenuated typhus v..
  • Rocky Mountain spotted fever v.: suspension of inactivated Rickettsia rickettsii prepared by growing the rickettsiae in the embryonate yolk sac of fowl eggs.
  • rubella virus v., live: a live virus v. originally prepared from duck embryos (HPV77) but now prepared from human diploid cell cultures infected with rubella virus (RA27/3); administered as a single subcutaneous injection. See measles, mumps, and rubella v..
  • Sabin v.: an orally administered v. containing live, attenuated strains of poliovirus. See poliovirus vaccines.
  • Salk v.: the original poliovirus v., composed of virus propagated in monkey kidney tissue culture and inactivated. See poliovirus vaccines.
  • Semple v.: a modification of the original (Pasteur) rabies v., formerly widely used in the U.S., prepared from rabbit nerve tissue, inactivated with phenol and administered in 14–21 daily injections; has variable potency and is associated with a high incidence of postvaccinal demyelination.
  • smallpox v.: v. of live vaccinia virus suspensions prepared from cutaneous vaccinial lesions of calves (calf lymph) or chick embryo origin; not currently used because of the worldwide elimination of smallpox.
  • split-virus v.: subunit v..
  • staphylococcus v.: a suspension of organisms from cultures of one or more strains of Staphylococcus; used for furunculosis, acne, and other suppurative conditions.
  • stock v.: a v. made from a stock microbial strain, in contradistinction to an autogenous v..
  • subunit v.: a v. which, through chemical extraction, is free of viral nucleic acid and contains only specific protein subunits of a given virus; such vaccines are relatively free of the adverse reactions ( e.g., influenza virus) associated with vaccines containing the whole virion.
  • T.A.B. v.: typhoid-paratyphoid A and B v..
  • tetanus v.: diphtheria toxoid, tetanus toxoid, and pertussis v..
  • tuberculosis v.: BCG v..
  • typhoid v.: a suspension of Salmonella typhi inactivated either by heat or by chemical (acetone) with an added preservative; in the U.S., the combined typhoid and paratyphoid A and B vaccines have been largely replaced by the monovalent typhoid v. because of the lack of evidence of effectiveness of paratyphoid A and paratyphoid B ingredients.
  • typhoid-paratyphoid A and B v.: a suspension of killed typhoid and paratyphoid A and B bacilli. SEE ALSO: typhoid v.. SYN: T.A.B. v..
  • typhus v.: a formaldehyde-inactivated suspension of Rickettsia prowazekii grown in embryonated eggs; effective against louse-borne (epidemic) typhus; primary immunization consists of two subcutaneous injections 4 or more weeks apart; booster doses are required every 6–12 months, as long as the possibility of exposure exists. A v. containing living rickettsiae of an attenuated strain of R. prowazekii has also been used.
  • whooping-cough v.: diphtheria toxoid, tetanus toxoid, and pertussis v..
  • yellow fever v.: a living, attenuated strain (17D) of yellow fever virus propagated in embryonated fowl eggs; also, a suspension of dried mouse brain infected with French neurotropic (Dakar) strain of yellow fever virus, administered topically by the scratch method; not officially recommended in the United States because of meningoencephalitic reactions.
vaccinia (vak-sin′e-a)
  • An infection, primarily local and limited to the site of inoculation, induced in humans by inoculation with the v. virus, type species in the genus Orthopoxvirus (family Poxviridae) in order to confer resistance to smallpox. On about the third day after this vaccination, papules form at the site of inoculation which become transformed into umbilicated vesicles and later pustules; they then dry up, and the scab falls off on about the 21st day, leaving a pitted scar; in some cases there are more or less marked constitutional disturbances. Because of the global elimination of smallpox, routine vaccination is not now practiced, aka primary reaction, vaccina, variola vaccine, variola v., variola v.. [L. vaccinus, relating to a cow, fr. vacca, a cow]
  • v. gangrenosa: progressive v..
  • generalized v.: secondary lesions of the skin following vaccination that may occur in subjects with previously healthy skin but are more common in the case of traumatized skin, especially in the case of eczema (eczema vaccinatum). In the latter instance, generalized v. may result from mere contact with a vaccinated person. Secondary vaccinial lesions may also occur following transfer of virus from the vaccination to another site by means of the fingers.
  • progressive v.: a severe or even fatal form of v. occurring chiefly in subjects with an immunologic deficiency or dyscrasia and characterized by progressive enlargement of the initial and also of secondary lesions, aka v. gangrenosa.
  • variola v.: v..
vaccinial (vak-sin′e-al)
Relating to vaccinia.

vacciniform (vak-sin′i-form)
Resembling vaccinia.

vaccinist (vak′si-nist)
SYN: vaccinator (1) .

vaccinization (vak′sin-i-za′shun)
Vaccination repeated at short intervals until it will no longer take.

vaccinogen (vak-sin′-o-jen)
A source of vaccine, such as an inoculated heifer.

vaccinogenous (vak-si-noj′e-nus)
Producing vaccine, or relating to the production of vaccine.

vaccinoid (vak′si-noyd)
Resembling vaccinia.

vaccinostyle (vak′si-no-stil)
A pointed instrument used in vaccination.

vaccinum (vak′si-num)
SYN: vaccine. [L.]

vacuolar (vak-oo-o′lar)
Relating to or resembling a vacuole.

vacuolate, vacuolated (vak′oo-o-lat, -lat′ed)
Having vacuoles.

vacuolation (vak′oo-o-la′shun)
1. Formation of vacuoles. 2. The condition of having vacuoles. SYN: vacuolization.

vacuole (vak′oo-ol)
1. A minute space in any tissue. 2. A clear space in the substance of a cell, sometimes degenerative in character, sometimes surrounding an englobed foreign body and serving as a temporary cell stomach for the digestion of the body. [Mod. L. vacuolum, dim. of L. vacuum, an empty space] autophagic v. SYN: cytolysosome. contractile v. a cavity formed by the accumulation of fluid in the ectoplasm of a protozoan; after increasing for a time it empties itself externally by a sudden contraction; it functions as an osmoregulatory mechanism for water balance, especially in freshwater protozoans. digestive v. SYN: secondary lysosomes, under lysosome. parasitophorous v. a v. formed by layers of endoplasmic reticulum around an intracellular parasite which may serve to isolate the parasite and enclose it for lysozymal attack.

vacuolization (vak′oo-o-li-za′shun)
SYN: vacuolation.

vacuome (vak′oo-om)
A system of vacuoles that can be stained with neutral red in the living cell. [vacuole + G. -oma, tumor]

vacuum (vak′oom)
An empty space, one practically exhausted of air or gas. [L. ntr. of vacuus, empty]

vadum (va′dum)
An occasional elevation from the bottom of a cerebral sulcus nearly obliterating it for a short distance. [L. a ford]

vagal (va′gal)
Relating to the vagus nerve.

vagectomy (va-jek′to-me)
Surgical removal of a segment of a vagus nerve.

vagi (va′gi, -ji)
Plural of vagus.

See vagino-.

vagina, gen. and pl. vaginae (va-ji′na, -ne)
  • sheath
  • the genital canal in the female, extending from the uterus to the vulva. [L. sheath, the v.]
  • bipartite v.: septate v..
  • v. bulbi: fascial sheath of eyeball.
  • v. carotica: carotid sheath.
  • v. cellulosa: the connective tissue sheath of a nerve or muscle (perineurium or perimysium, respectively).
  • v. communis tendinum musculorum flexorum (manus): common flexor sheath (of hand).
  • v. communis tendinum musculorum fibularium communis: common peroneal tendon sheath.
  • v. externa nervi optici: outer sheath of optic nerve.
  • vaginae fibrosae digitorum manus: fibrous sheaths of digits of hand, under sheath. See anular part of fibrous digital sheath of digits of hand and foot, cruciform part of fibrous digital sheath.
  • vaginae fibrosae digitorum pedis: fibrous digital sheaths of toes, under sheath. See anular part of fibrous digital sheath of digits of hand and foot, cruciform part of fibrous digital sheath.
  • v. fibrosa tendinis: fibrous tendon sheath.
  • v. interna nervi optici: inner sheath of optic nerve.
  • v. masculina: prostatic utricle.
  • v. mucosa tendinis: synovial tendon sheath.
  • v. musculi recti abdominis: rectus sheath.
  • vaginae nervi optici sheaths of the optic nerve, formed by extensions of the central meninges. See inner sheath of optic nerve, external sheath of optic nerve.
  • v. oculi: fascial sheath of eyeball.
  • v. processus styloidei: sheath of styloid process.
  • septate v. a bipartite v. caused by the presence of a more or less complete longitudinal septum, aka bipartite v..
  • vaginae synoviales digitorum manus: synovial sheaths of digits of hand, under sheath.
  • v. synovialis: synovial sheath.
  • v. synovialis tendinis: synovial tendon sheath.
  • v. synovialis trochleae: tendinous sheath of superior oblique muscle.
  • vaginae tendinum carpalium: carpal tendinous sheaths, under sheath.
  • vaginae tendinum carpalium dorsalium: dorsal carpal tendinous sheaths, under sheath.
  • v. tendinis intertubercularis: intertubercular tendon sheath.
  • v. tendinis musculi extensoris carpi ulnaris: tendinous sheath of extensor carpi ulnaris muscle.
  • v. tendinis musculi extensoris digiti minimi: tendinous sheath of extensor digiti minimi muscle.
  • v. tendinis musculi extensoris hallucis longi: tendinous sheath of extensor hallucis longus muscle.
  • v. tendinis musculi extensoris pollicis longi: tendinous sheath of extensor pollicis longus muscle.
  • v. tendinis musculi fibularis longi plantaris: plantar tendon sheath of fibularis longus muscle.
  • v. tendinis musculi flexoris carpi radialis: tendinous sheath of flexor carpi radialis muscle.
  • v. tendinis musculi flexoris hallucis longi: tendinous sheath of flexor hallucis longus muscle.
  • v. tendinis musculi flexoris pollicis longi: tendinous sheath of flexor pollicis longus muscle.
  • v. tendinis musculi obliqui superioris: tendinous sheath of superior oblique muscle.
  • v. tendinis musculi peronei longi plantaris plantar tendon sheath of fibularis longus muscle.
  • v. tendinis musculi tibialis anterioris: tendinous sheath of tibialis anterior muscle.
  • v. tendinis musculi tibialis posterioris: tendinous sheath of tibialis posterior muscle.
  • vaginae tendinum carpales palmares: palmar carpal tendinous sheaths, under sheath.
  • vaginae tendinum digitorum pedis: synovial sheaths of toes, under sheath.
  • v. tendinum musculi extensoris digitorum pedis longi: tendinous sheath of extensor digitorum longus muscle of foot.
  • v. tendinum musculi flexoris digitorum pedis longi: tendinous sheath of flexor digitorum longus muscle (of foot).
  • v. tendinum musculorum abductoris longi et extensoris brevis pollicis: tendinous sheath of abductor pollicis longus and extensor pollicis brevis muscles.
  • v. tendinum musculorum extensoris digitorum et extensoris indicis: tendinous sheath of extensor digitorum and extensor indicis muscles.
  • v. tendinum musculorum extensorum carpi radialium: tendinous sheath of extensor carpi radialis muscles.
  • v. tendinum musculorum fibularium communis: common peroneal tendon sheath.
  • v. tendinum musculorum peroneorum communis: common peroneal tendon sheath.
  • vaginae tendinum tarsales anteriores: anterior tarsal tendinous sheaths, under sheath.
  • vaginae tendinum tarsales fibulares: fibular tarsal tendinous sheaths, under sheath.
  • vaginae tendinum tarsales tibialis: tibial tarsal tendinous sheaths, under sheath.
  • vaginae vasorum: vascular sheaths, under sheath.
vaginal (vaj′i-nal)
Relating to the vagina or to any sheath. [Mod. L. vaginalis]

vaginapexy (va-ji′na-pek-se)
SYN: vaginofixation.

vaginate (vaj′i-nat)
1. To ensheathe; to enclose in a sheath. 2. Ensheathed; provided with a sheath.

vaginectomy (vaj-i-nek′to-me)
Excision of the vagina or a segment thereof, aka colpectomy. [vagina + G. ektome, excision]

vaginism (vaj′i-nizm)
SYN: vaginismus.

vaginismus (vaj-i-niz′mus)
Painful spasm of the vagina preventing intercourse. SYN: vaginism, vulvismus. [vagina + L. -ismus, action, condition] posterior v. spasmodic stenosis of the vagina caused by contraction of the levator ani muscle.

vaginitis, pl .vaginitides (vaj-i-ni′tis, -ni′ti-dez)
Inflammation of the vagina. [vagina + G. -itis, inflammation] v. adhesiva SYN: adhesive v.. adhesive v. inflammation of vaginal mucosa with adhesions of the vaginal walls to each other. SYN: v. adhesiva. amebic v. v. caused by Entamoeba histolytica. atrophic v. thinning and atrophy of the vaginal epithelium usually resulting from diminished estrogen stimulation; a common occurrence in postmenopausal women. v. cystica SYN: v. emphysematosa. desquamative inflammatory v. an acute inflammation of the vagina of unknown cause, characterized by grayish pseudomembrane, free discharge, and easy bleeding on trauma; the discharge contains pus and immature epithelial cells, although estrogen levels are normal. v. emphysematosa v. characterized by accumulation of gas in small connective tissue spaces lined by foreign-body giant cells. SYN: pachyvaginitis cystica, v. cystica. Gardnerella v. SYN: bacterial vaginosis. nonspecific v. SYN: bacterial vaginosis. pinworm v. v. caused by Enterobius vermicularis. senile v. atrophic v. resulting from withdrawal of estrogen stimulation of mucosa, often assuming the form of adhesive v.. SYN: v. senilis. v. senilis SYN: senile v..

vagino-, vagin-
The vagina. SEE ALSO: colpo-. [L. vagina, sheath]

vaginoabdominal (vaj′i-no-ab-dom′i-nal)
Relating to the vagina and the abdomen.

vaginocele (vaj′i-no-sel)
SYN: colpocele (1) .


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