| FEF50 | forced expiratory flow at 50% of forced vital capacity |
|---|---|
| FEF50/FIF50 | ratio of expiratory flow to inspiratory flow at 50% of forced vital capacity |
| FIF | feedback inhibition factor; fibroblast interferon; forced inspiratory flow; formaldehyde-induced flu... |
| FIO2 | forced inspiratory oxygen; fractional concentration of oxygen in inspired gas |
| FIS | forced inspiratory spirogram; free induction signal |
| forced grasping reflex | An involuntary flexion of the fingers to tactile or tendon stimulation on the palm of the hand, producing an uncontrollable grasp; usually associated with frontal lobe lesions. Compare: darwinian reflex. Synonym: forced grasping reflex, grasp reflex. (05 Mar 2000) |
|---|---|
| forced respiration | Voluntary hyperventilation. (05 Mar 2000) |
| forced vital capacity | Vital capacity measured with the subject exhaling as rapidly as possible; data relating volume, expiratory flow, and time form the basis for other pulmonary function tests, e.g., flow-volume curve, forced expiratory volume, forced expiratory time, forced expiratory flow. (05 Mar 2000) |
| atomic volume | The atomic weight of an element divided by its density in the solid state; the volume of the gram-atomic weight of a solid element. (05 Mar 2000) |
| blood volume | Volume of circulating blood. It is the sum of the plasma volume and erythrocyte volume. (12 Dec 1998) |
| blood volume determination | Method for determining the circulating blood volume by introducing a known quantity of foreign substance into the blood and determining its concentration some minutes later when thorough mixing has occurred. From these two values the blood volume can be calculated by dividing the quantity of injected material by its concentration in the blood at the time of uniform mixing. Generally expressed as cubic centimeters or liters per kilogram of body weight. (12 Dec 1998) |
| blood volume nomogram | A nomogram used to predict blood volume on the basis of the individual's weight and height. (05 Mar 2000) |
| cardiac volume | The volume of the heart, usually relating to the volume of blood contained within it at various periods of the cardiac cycle. The amount of blood ejected from a ventricle at each beat is stroke volume. (12 Dec 1998) |
| packed cell volume | <haematology> Measurement of the proportion of the blood occupied by the red blood cells. Normal values are 40-54% in males, 35-47% in females. (13 Nov 1997) |
| maximal expiratory flow-volume curve | <chest medicine> Curves depicting maximal expiratory flow in liters/second at each point of lung inflation (expressed in liters or percentage of forced vital capacity) during a forced vital capacity determination. Common abbreviation is mefv. (12 Dec 1998) |
| partial volume | The actual volume occupied by one species of molecule or particle in a solution; the reciprocal of the density of the molecule. (05 Mar 2000) |
| mean corpuscular volume | The average volume of red cells, calculated from the haematocrit and the red cell count, in erythrocyte indices. (05 Mar 2000) |
| residual volume | The volume of air remaining in the lungs at the end of a maximal expiration. Common abbreviation is rv. (12 Dec 1998) |
| volume | 1. A roll; a scroll; a written document rolled up for keeping or for use, after the manner of the ancients. "The papyrus, and afterward the parchment, was joined together [by the ancients] to form one sheet, and then rolled upon a staff into a volume (volumen)." (Encyc. Brit) 2. Hence, a collection of printed sheets bound together, whether containing a single work, or a part of a work, or more than one work; a book; a tome; especially, that part of an extended work which is bound up together in one cover; as, a work in four volumes. "An odd volume of a set of books bears not the value of its proportion to the set." (Franklin) 4. Anything of a rounded or swelling form resembling a roll; a turn; a convolution; a coil. "So glides some trodden serpent on the grass, And long behind wounded volume trails." (Dryden) "Undulating billows rolling their silver volumes." (W. Irving) 4. Dimensions; compass; space occupied, as measured by cubic units, that is, cubic inches, feet, yards, etc.; mass; bulk; as, the volume of an elephant's body; a volume of gas. 5. Amount, fullness, quantity, or calibre of voice or tone. <chemistry> Atomic volume, Molecular volume, the ratio of the atomic and molecular weights divided respectively by the specific gravity of the substance in question. <physics> Specific volume, the quotient obtained by dividing unity by the specific gravity; the reciprocal of the specific gravity. It is equal (when the specific gravity is referred to water at 4 deg C. As a standard) to the number of cubic centimeters occupied by one gram of the substance. Origin: F, from L. Volumen a roll of writing, a book, volume, from volvere, volutum, to roll. See Voluble. Source: Websters Dictionary (01 Mar 1998) |
| volume 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. (05 Mar 2000) |