IUPAC Glossary of Terms Used in Toxicology – V

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

vacuole
Membrane-bound cavity within a cell.

validity of a measurement
Expression of the degree to which a measurement measures what it purports to measure.

validity of a study
Degree to which the inferences drawn, especially generalizations extending beyond the study sample, are warranted when account is taken of the study methods, the representativeness of the study sample, and the nature of the population from which it is drawn.

vasoconstriction
antonym vasodilation
Decrease of the caliber of the blood vessels leading to a decreased blood flow.

vasodilation
antonym vasoconstriction
Increase in the caliber of the blood vessels, leading to an increased blood flow.

vector
See cloning vector

vehicle
Substance(s) used to formulate active ingredients for administration or use.
Note: In this context, it is a general term for solvents, suspending agents, etc.

venom
Animal toxin generally used for self-defense or predation and usually delivered by a bite or sting.

ventilation
  1. Process of supplying a building or room with fresh air.
  2. Process of exchange of air between the ambient atmosphere and the lungs.
  3. In physiology, the amount of air inhaled per day.
  4. Oxygenation of blood.

ventricular fibrillation
Irregular heartbeat characterized by uncoordinated contractions of the ventricle.

vermicide
Substance intended to kill intestinal worms.

vermifuge
See anthelmint(h)ic

vertigo
Dizziness; an illusion of movement as if the external world were revolving around an individual or as if the individual were revolving in space.

vesicant
  1. adj., Producing blisters on the skin.
  2. n., Substance that causes blisters on the skin.
vesicle
  1. In cell biology, small bladder-like, membrane-bound sac containing aqueous solution or fat.
  2. In pathology, blisterlike elevation on the skin containing serous fluid.

virtually safe dose (VSD)
Human exposure over a lifetime to a carcinogen which has been estimated, using mathematical modeling, to result in a very low incidence of cancer, somewhere between zero and a specified incidence, e.g. one cancer in a million exposed people.

virucide
antiviral
Substance used to control viruses.
[6]

volume of distribution
Apparent (hypothetical) volume of fluid required to contain the total amount of a substance in the body at the same concentration as that present in the plasma assuming equilibrium has been attained.

volatile organic chemicals (VOC)
Any organic compound having, at 293.15 K, a vapor pressure of 0.01 kPa or more, or having a corresponding volatility under the particular condition of use.
[15]

vulnerable
See susceptible

Last updated: 18 July 2007
First published: 18 July 2007
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