| VCS | vasoconstrictor substance; vesicocervical space |
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| VD | vapor density; vascular disease; vasodilation, vasodilator; venereal disease; venous dilatation; ven... |
| VD | dead space |
| Vd | voided, voiding; volume dead space; volume of distribution |
| Vd/Vt | dead space ventilation/total ventilation [ratio] |
| central tegmental fasciculus | A large fibre bundle passing longitudinally through the central mesencephalic and pontine tegmentum, distinguished from adjacent longitudinal groups of fibre-fascicles of the reticular formation by a more compact composition. In transverse sections of the mesencephalon the bundle occupies a large triangular area lateral to the medial longitudinal fasciculus; farther caudally it expands ventralward and finally passes over the lateral side of the (inferior) olivary nucleus, becoming part of the latter's fibre capsule. The bundle contains fibres from the mesencephalic tegmentum and regions surrounding the central gray substance descending to the olivary nucleus; it also includes numerous fibres ascending from the medullary, pontine, and mesencephalic reticular formation to the thalamus and subthalamus region. Synonym: tractus tegmentalis centralis, central tegmental fasciculus, tractus centralis tegmenti. (05 Mar 2000) |
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| central tegmental tract | A large fibre bundle passing longitudinally through the central mesencephalic and pontine tegmentum, distinguished from adjacent longitudinal groups of fibre-fascicles of the reticular formation by a more compact composition. In transverse sections of the mesencephalon the bundle occupies a large triangular area lateral to the medial longitudinal fasciculus; farther caudally it expands ventralward and finally passes over the lateral side of the (inferior) olivary nucleus, becoming part of the latter's fibre capsule. The bundle contains fibres from the mesencephalic tegmentum and regions surrounding the central gray substance descending to the olivary nucleus; it also includes numerous fibres ascending from the medullary, pontine, and mesencephalic reticular formation to the thalamus and subthalamus region. Synonym: tractus tegmentalis centralis, central tegmental fasciculus, tractus centralis tegmenti. (05 Mar 2000) |
| central tendon of diaphragm | A three-lobed fibrous sheet occupying the centre of the diaphragm. Synonym: centrum tendineum diaphragmatis, trefoil tendon. Central tendon of perineum, the fibromuscular mass between the anal canal and the urogenital diaphragm in the median plane; midline episiotomies extend into this structure. Synonym: centrum tendineum perinei, perineal body, Savage's perineal body. (05 Mar 2000) |
| central terminal electrode | In electrocardiography, an electrode in which connections from the three limbs (right arm, left arm, and left leg) are joined and led to the electrocardiograph to form the indifferent electrode, theoretically at zero potential for the system. (05 Mar 2000) |
| central thalamic radiations | Radiations formed by fibres interconnecting, through the posterior limb of the internal capsule, the ventral lateral, ventral posterolateral and posteromedial, lateral dorsal, and lateral posterior nuclei and the precentral gyrus and parietal lobe of the cerebral cortex. (05 Mar 2000) |
| central transactional core | The reticular activating system of the brain. (05 Mar 2000) |
| central type neurofibromatosis | Type I neurofibromatosis. Incomplete neurofibromatosis, multiple neurofibromas with minimal manifestations, perhaps limited to cafe-au-lait spots; individuals with minimal lesions may have offspring with severe involvement. Synonym: abortive neurofibromatosis. (05 Mar 2000) |
| central vein of retina | Formed by union of the retinal veins and accompanies the artery of the same name in the optic nerve. Synonym: vena centralis retinae. (05 Mar 2000) |
| central vein of suprarenal gland | The single draining vein of the gland; it receives a number of medullary veins; on the right side it empties directly into the inferior vena cava and on the left into the left renal vein. Synonym: vena centralis glandulae suprarenalis. (05 Mar 2000) |
| central veins of liver | The terminal branches of the hepatic veins that lie centrally in the hepatic lobules and receive blood from the liver sinusoids. Synonym: venae centrales hepatis, Krukenberg's veins. (05 Mar 2000) |
| central venous catheter | <equipment> Small, flexible plastic tube inserted into the large vein above the heart, through which drugs and blood products can be given and blood samples withdrawn painlessly. Synonym: central line, Hickman catheter. (12 Jan 1998) |
| central venous line | <equipment> Small, flexible plastic tube inserted into the large vein above the heart, through which drugs and blood products can be given and blood samples withdrawn painlessly. Synonym: central line, Hickman catheter. (12 Jan 1998) |
| central venous pressure | The venous pressure as measured at the right atrium, done by means of a catheter introduced through the median cubital vein to the superior vena cava, the distal end of the catheter being attached to a manometer. (12 Dec 1998) |
| central vision | Vision stimulated by an object imaged on the fovea centralis. Synonym: direct vision. (05 Mar 2000) |
| peripherally inserted central catheter | <equipment> A catheter inserted into an arm vein and used for periods of up to three months. This catheter does not need to be surgically implanted and can be inserted at home by a trained nurse. (09 Oct 1997) |