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Medical Dictionary


vasoconstrictive (va′so-kon-strik′tiv, vas′o-)
1. Causing narrowing of the blood vessels. 2. SYN: vasoconstrictor (1) .

vasoconstrictor (va′so-kon-strik′ter, vas′o-)
1. An agent that causes narrowing of the blood vessels. SYN: vasoconstrictive (2) . 2. A nerve, stimulation of which causes vascular constriction.

vasodentin (va-so-den′tin, vas-o-)
Dentin in which the primitive capillaries have remained uncalcified and so are wide enough to give passage to the formed elements of the blood. SYN: vascular dentin.

vasodepression (va′so-de-presh′un, vas′o)
Reduction of tone in blood vessels with vasodilation and resulting in lowered blood pressure.

vasodepressor (va′so-de-pres′er, vas′o)
1. Producing vasodepression. 2. SYN: depressor (4) .

vasodilatation (va′so-dil-a-ta′shun, vas′o-)
SYN: vasodilation.

vasodilation (va′so-di-la′shun, vas-o-)
Widening of the lumen of blood vessels. SYN: vasodilatation. active v. v. caused by a decrease in tonus of smooth muscle in the wall of a vessel. passive v. v. related to increased pressure in lumen of a vessel.

vasodilative (va′so-di-la′tiv, vas′o-)
1. Causing dilation of the blood vessels. 2. SYN: vasodilator (1) .

vasodilator (va′so-di-la′ter, vas′o-)
1. An agent that causes dilation of the blood vessels. SYN: vasodilative (2) . 2. A nerve, stimulation of which results in dilation of the blood vessels.

vasoepididymostomy (va′so-ep-i-did-i-mos′to-me, vas′o-)
Surgical anastomosis of the vasa deferentia to the epididymis, to bypass an obstruction at the level of the mid to distal epididymis or proximal vas. [vaso- + epididymis + G. stoma, mouth]

vasofactive (va-so-fak′tiv, vas-o-)
SYN: angiopoietic.

vasoformation (va-so-for-ma′shun, vas-o-)
SYN: angiopoiesis.

vasoformative (va-so-for′ma-tiv, vas-o-)
SYN: angiopoietic.

vasoganglion (va-so-gang′gle-on, vas-o-)
A mass of blood vessels.

vasography (va-sog′ra-fe)
Radiography of the vas deferens to determine patency, by injecting contrast medium into its lumen either transurethrally or by open vasotomy. [vas + G. grapho, to write]

vasoinhibitor (va′so-in-hib′i-ter, vas′o-)
An agent that restricts or prevents the functioning of the vasomotor nerves.

vasoinhibitory (va′so-in-hib′i-tor-e, vas′o-)
Restraining vasomotor action.

vasolabile (va-so-la′bil, -bil, vas-o-)
Characterizing the condition in which there is lability or active vasomotion of blood vessels.

vasoligation (va′so-li-ga′shun, vas′o-)
Ligation of the vas deferens, usually after its division.

vasomotion (va-so-mo′shun, vas-o-)
Change in caliber of a blood vessel.

vasomotor (va-so-mo′ter, vas-o-)
1. Causing dilation or constriction of the blood vessels. 2. Denoting the nerves which have this action. SYN: vasculomotor.

vasoneuropathy (va′so-noo-rop′a-the, vas′o-)
Any disease involving both the nerves and blood vessels. [vaso- + G. neuron, nerve, + pathos, suffering]

vaso-orchidostomy (va′so-or-ki-dos′to-me, vas′o-)
Reestablishment of the interrupted seminiferous channels by uniting the tubules of the epididymis or of the rete testis to the divided end of the vas deferens. [vaso- + G. orchis, testis, + stoma, mouth]

vasoparalysis (va′so-pa-ral′i-sis, vas′o-)
Paralysis, atonia, or hypotonia of blood vessels. SYN: angiohypotonia, angioparalysis.

vasoparesis (va′so-pa-re′sis, -par′e-sis, vas′o-)
A mild degree of vasoparalysis. SYN: angioparesis, vasomotor paralysis. [vaso- + G. paresis, weakness]

vasopressin (VP) (va-so-pres′in, vas-o-)
A nonapeptide neurohypophysial hormone related to oxytocin and vasotocin; synthetically prepared or obtained from the posterior lobe of the pituitary of healthy domestic animals. In pharmacological doses v. causes contraction of smooth muscle, notably that of all blood vessels; large doses may produce cerebral or coronary arterial spasm. SYN: antidiuretic hormone, Pitressin. [vaso- + L. premo, pp. pressum, to press down, + -in] arginine v. (AVP) v. containing an arginyl residue in position 8 (as in chickens and most mammals, including humans); porcine v. has a lysyl residue at position 8. All are vasopressors. SYN: argipressin.

vasopressor (va-so-pres′er, vas-o-)
1. Producing vasoconstriction and a rise in blood pressure, usually understood to be systemic arterial pressure unless otherwise specified. 2. An agent that has this effect.

vasopuncture (va-so-punk′choor, vas-o-)
The act of puncturing a vessel with a needle.

vasoreflex (va-so-re′fleks, vas′o-)
A reflex that influences the caliber of blood vessels.

vasorelaxation (va′so-re-lak-sa′shun, vas-o)
Reduction in tension of the walls of the blood vessels.

vasosection (va-so-sek′shun, vas-o-)
SYN: vasotomy.

vasosensory (va-so-sen′ser-e, vas-o-)
1. Relating to sensation in the blood vessels. 2. Denoting sensory nerve fibers innervating blood vessels.

vasospasm (va′so-spazm, vas′o-)
Contraction or hypertonia of the muscular coats of the blood vessels. SYN: angiohypertonia, angiospasm.

vasospastic (va-so-spas′tik, vas-o-)
Relating to or characterized by vasospasm. SYN: angiospastic.

vasostimulant (va-so-stim′u-lant)
1. Exciting vasomotor action. 2. An agent that excites the vasomotor nerves to action. 3. SYN: vasotonic (2) .

vasostomy (va-sos′to-me)
Establishment of an opening into the deferent duct. [vaso- + G. stoma, mouth]

vasothrombin (va-so-throm′bin, vas-o-)
Thrombin derived from the lining cells of the blood vessels.

vasotocin (va-so-to′sin, vas-o-)
A nonapeptide hormone of the neurohypophysis of subvertebrates, with activities similar to that of vasopressin and oxytocin; chemically identical with human vasopressin except for an isoleucyl residue at position 3; thus [3-isoleucine]vasopressin or [Ile3]vasopressin. [vaso, pressin + oxytocin] arginine v. v. with arginyl residue at position 8 (identical with arginine oxytocin). SEE ALSO: arginine vasopressin.

vasotomy (va-sot′o-me)
Incision into or division of the vas deferens. SYN: vasosection. [vaso- + G. tome, incision]

vasotonia (va-so-to′ne-a, vas-o-)
The tone of blood vessels, particularly the arterioles. [vaso- + G. tonos, tone]

vasotonic (va-so-ton′ik, vas-o-)
1. Relating to vascular tone. 2. An agent that increases vascular tension. SYN: vasostimulant (3) .

vasotrophic (va-so-trof′ik, vas-o-)
Relating to the nutrition of the blood vessels or the lymphatics. [vaso- + G. trophe, nourishment]

vasotropic (va-so-tro′pik, vas-o-)
Tending to act on the blood vessels. [vaso- + G. trope, a turning]

vasovagal (va-so-va′gal, vas-o-)
Relating to the action of the vagus nerve upon the blood vessels.

vasovasostomy (va′so-va-sos′to-me, vas′o-)
Surgical anastomosis of vasa deferentia, to restore fertility in a previously vasectomized male. [vaso- + vaso- + G. stoma, mouth]

vasovesiculectomy (va′so-ve-sik-u-lek′to-me, vas′o-)
Excision of the vas deferens and seminal vesicles. [vaso- + L. vesicula, vesicle, + G. ektome, excision]

vastomy (vas′to-me)
Section of the vas deferens, usually with ligation. [vas + G. tome, a cutting]

vastus (vas′tus)
Great. See v. intermedius (muscle), v. lateralis (muscle), v. medialis (muscle ). [L.]

Acronym for vertebral defects, anal atresia, tracheoesophageal fistula with esophageal atresia, and radial and renal anomalies. See V. complex.

Abraham, German anatomist and botanist, 1684–1751. See ampulla of V., V. corpuscles, under corpuscle, V. fold, V.-Pacini corpuscles, under corpuscle.

Abbreviation for video-assisted thoracic surgery.

vault (vawlt)
A part resembling an arched roof or dome, e.g., the pharyngeal v. or fornix, the nonmuscular upper part of the nasopharynx; the palatine v., arch of the plate; v. of the vagina, fornix of vagina. [thr. O. Fr., fr. L. volvo, pp. volutus, to turn round] cranial v. SYN: neurocranium. v. of pharynx [TA] the nonmuscular, noncollapsing upper end of the nasopharynx where the pharyngeal mucosa is firmly applied to the body of the sphenoid bone and to pharyngobasilar fascia. SYN: fornix pharyngis [TA] , pharyngeal fornix.

V-shaped bends incorporated in an archwire, usually placed mesially or distally to the canines (cuspids) and used as a “dead” area of wire through which torquing bends may be placed.

Abbreviation for colored vision; vital capacity.

Abbreviation for voiding cystourethrogram.

Abbreviation for Venereal Disease Research Laboratories. See V. test.

vection (vek′shun)
Transference of the agents of disease from an infected to an uninfected individual by a vector. [L. vectio, conveyance]

vectis (vek′tis)
An instrument resembling one of the blades of an obstetrical forceps, used as an aid in delivery by making leverge on the presenting part of the fetus. [L. a lever or bar]

vector (vek′ter, tor)
1. An invertebrate animal ( e.g., tick, mite, mosquito, bloodsucking fly) capable of transmitting an infectious agent among vertebrates. 2. Anything ( e.g., velocity, mechanical force, electromotive force) having magnitude and direction; it can be represented by a straight line of appropriate length and direction. 3. The net electrical axis of any ECG wave (usually QRS) whose length is proportional to the magnitude of the electrical force, whose direction gives the direction of the force, and whose tip represents the positive pole of the force. 4. DNA such as a chromosome or plasmid that autonomously replicates in a cell to which another DNA segment may be inserted and be itself replicated, as in cloning. 5. SYN: recombinant v.. 6. Recombinant DNA systems especially suited for production of large quantities of specific proteins in bacterial, yeast, insect, or mammalian cell systems. [L. v., a carrier] biologic v. a v., such as the Anopheles mosquito for malarial agents or the tsetse fly for agents of African sleeping sickness, in which the agent multiplies prior to being transmitted to another host. cloning v. an autonomously replicating plasmid or phage with regions that are not essential for its propagation in bacteria and into which foreign DNA can be inserted; this foreign DNA is replicated and propagated as if it were a normal component of the v.. expression v. a v. (plasmid, yeast, or animal virus genome) used experimentally to introduce foreign genetic material into a propagatable host cell in order to replicate and amplify the foreign DNA sequences as a recombinant molecule (recombinant DNA cloning of sequences). instantaneous v. the resultant v. of the heart's action currents at any given moment, usually represented as an arrow of appropriate direction and magnitude. manifest v. projection of a spatial cardiac v. on a single plane. mean v. a single cardiac v. representing the average of all vectors present during a given time interval. SYN: mean manifest v.. mean manifest v. SYN: mean v.. mechanical v. a v. that conveys pathogens to a susceptible individual without essential biologic development of the pathogens in the v., as in the transfer of septic organisms on the feet or mouth parts of the housefly. recombinant v. a v. into which a foreign DNA has been inserted. SYN: v. (5) . retroviral v. a specially constructed retrovirus containing one or more genes to correct certain genetic disorders. shuttle v. a v. (4) that contains both bacterial and eukaryotic replication signals; thus, replication can occur in both types of cells. spatial v. a cardiac v. represented in more than one plane simultaneously; two- or three-dimensional orientation of a v..

vector-borne (vek′ter-born)
Denoting a disease or infection that is transmitted by an invertebrate vector.

vectorcardiogram (vek′tor-kar′de-o-gram)
A graphic representation of the instant-to-instant magnitude and direction of the heart's action currents in the form of vector loops.

The integration of scalar electrocardiographic recordings on two or three planes to produce a vectorcardiogram consisting of loops divided by a timing mechanism for all the waves of the electrocardiogram. spatial v. three-dimensional v. in which vector loops are inscribed in frontal, sagittal, and horizontal planes.

vectorial (vek-tor′e-al)
Relating in any way to a vector.

vecuronium bromide (ve-ku-ro′ne-um)
A nondepolarizing neuromuscular relaxant with a relatively short duration of action; a monoquaternary homolog of pancuronium.

Abbreviation for Venezuelan equine encephalomyelitis.

vegan (veg′an)
A strict vegetarian; i.e., one who consumes no animal or dairy products of any type. Cf.:vegetarian.

vegetable (vej′ta-bl, vej′e-ta-bl)
1. A plant, specifically one used for food. 2. Relating to plants, as distinguished from animals or minerals. SYN: vegetal (1) . [M.E., fr. L. vegetabilis (see vegetation)]

vegetal (vej′e-tal)
1. SYN: vegetable (2) . 2. Denoting the vital functions common to plants and animals, such as respiration, metabolism, growth, generation, etc., distinguished from those peculiar to animals, such as conscious sensation and the mental faculties.

vegetality (vej-e-tal′i-te)
The aggregate of the vital functions common to both plants and animals.

vegetarian (vej-e-tar′e-an)
One whose diet is restricted to foods of vegetable origin, excluding primarily animal meats. Cf.:vegan. lacto-ovo-v. a v. who consumes dairy products and eggs but does not eat animal flesh. ovo-v. a v. who consumes eggs but does not consume dairy products nor animal flesh. semi-v. a v. who consumes dairy products, eggs, chicken, and fish, but does not consume other animal flesh.


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