- Space occupied by matter, expressed usually in cubic millimeters, cubic centimeters, liters, etc. See water. SEE ALSO: capacity. [L. volumen, something rolled up, scroll, fr. volvo, to roll]- atomic v. the atomic weight of an element divided by its density in the solid state; the v. of the gram-atomic weight of a solid element.- v. averaging in computed tomography or magnetic resonance imaging, the effect of expressing the average density of a voxel as a pixel in the image; the greater the slice thickness, the more averaging is necessary, with loss in density resolution.- closing v. (CV) the lung v. at which the flow from the lower parts of the lungs becomes severely reduced or stops during expiration, presumably because of airway closure; measured by the sharp rise in expiratory concentration of a tracer gas that had been inspired at the beginning of a breath that started from residual v..- distribution v. the v. throughout which an added tracer substance appears to have been evenly distributed, calculated by dividing the amount of tracer added by its concentration after equilibration.- end- diastolic v. the capacity or the amount of blood in the ventricle immediately before a cardiac contraction begins; a measurement of cardiac filling between beats, related to diastolic function.- end- systolic v. the capacity or the amount of blood in the ventricle at the end of the ventricular ejection period and immediately preceding the beginning of ventricular relaxation; a measurement of the adequacy of cardiac emptying, related to systolic function.- expiratory reserve v. (ERV) the maximal v. of air (about 1000 mL) that can be expelled from the lungs after a normal expiration. SYN: reserve air, supplemental air.- extracellular fluid v. (ECFV) the fraction of body water not in cells, about 25% of body weight : it consists of plasma water (4.5% of body weight), water between cells (interstitial water-lymph, 11.5% of body weight), water in dense bone and connective tissue (7.5% of body weight), and water secretions. See entries under entries under water.. SEE ALSO: intracellular fluid.- forced expiratory v. (FEV) the maximal v. that can be expired in a specific time interval when starting from maximal inspiration. A subscript annotation normally indicates the number of seconds the patient has been expiring e.g., FEV30–60.- inspiratory reserve v. (IRV) the maximal v. of air that can be inspired after a normal inspiration; the inspiratory capacity less the tidal v.. SYN: complemental air.- mean corpuscular v. (MCV) the average v. of red cells, calculated from the hematocrit and the red cell count, in erythrocyte indices.- minute v. the v. of any gas or fluid moved per minute; e.g., cardiac output or the respiratory minute v..- packed cell v. the v. of the blood cells in a sample of blood after it has been centrifuged in the hematocrit; normally, it amounts to 45% of the blood sample.- partial v. the actual v. occupied by one species of molecule or particle in a solution; the reciprocal of the density of the molecule.- residual v. (RV) the v. of air remaining in the lungs after a maximal expiratory effort. SYN: residual air, residual capacity.- respiratory minute v. (RMV) the minute v. of breathing; the product of tidal v. times the respiratory frequency. See pulmonary ventilation.- resting tidal v. the tidal v. under normal conditions, i.e., in the absence of exercise or other conditions that stimulate breathing.- tidal v. (VT) the v. of air that is inspired or expired in a single breath during regular breathing. SYN: tidal air.
* * *vol·ume 'väl-yəm, -(.)yüm n1) the amount of space occupied by a three-dimensional figure as measured in cubic units (as inches, quarts, or centimeters): cubic capacity2) the amount of a substance occupying a particular volume
* * *vol·ume (volґūm) the measure of the quantity or capacity of a substance. Symbol V or V.
Medical dictionary. 2011.