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a measure of duration. See under adjectives for specific times, such as bleeding time.
activated partial thromboplastin time (APTT, aPTT) the period required for clot formation in recalcified blood plasma after contact activation and the addition of platelet substitutes such as brain cephalins or similar phospholipids; used to assess the coagulation pathways. A prolonged aPTT can indicate a deficiency of any of various coagulation factors, including factors XII, XI, IX, VIII, X, V, and II, and fibrinogen.
AEC minimal response time the shortest duration at which x-ray exposure can be terminated by automatic exposure control.
atrioventricular sequential time a fixed nonprogrammable interval that extends from the atrial stimulus to the ventricular stimulus.
bleeding time the time required for a standardized wound to stop bleeding; used as a test for platelet disorders; see also bleeding time.
circulation time the time required for blood to flow between two given points; see also circulation time.
clotting time (coagulation time) the time required for blood to clot in a glass tube; see also clotting.
cold ischemia time the time between the placement of a traumatically amputated body part in ice and the time of surgical replantation.
inertia time the time required to overcome the inertia of a muscle after reception of a stimulus.
ischemia time the total time between traumatic amputation of a limb or portion of a limb and its surgical reimplantation; it is the sum of warm and cold ischemia times.
minimal response time in radiology, the shortest possible exposure time for an x-ray film to be exposed automatically.
one-stage prothrombin time prothrombin time.
prothrombin time see prothrombin time.
real time a term used to describe a recording device that shows events simultaneously to their occurrence.
R peak time intrinsicoid deflection.
thrombin time the time required for plasma fibrinogen to form thrombin; see also thrombin time.
warm ischemia time the time interval between traumatic amputation of a limb or part and its placement on ice.
the time taken for the blood to pass through a given circuit of the vascular system, for example, the pulmonary or systemic circulation, from one arm to another, from arm to tongue, or from arm to lung; it is measured by the injection into an arm vein of a substance, such as sodium dehydrocholate, ether, fluorescein, histamine, or a radium salt, which can be detected when it arrives at another point in the vascular system.
the time required for blood to flow from one part of the body to another. Timing a particle of blood involves injecting a traceable dye or radioisotope into a vein and timing its reappearance in an artery at the point of injection. Alternatively, a substance that can be tasted, such as saccharin, can be injected and the time it takes to travel to the tongue noted. The resulting time helps determine problems with heart failure and decreased cardiac output.
cir·cu·la·tion time(sĭrkyū-lāshŭn tīm)
Duration elapsed for blood to pass through a given circuit of the vascular system; measured by injection into an arm vein of a substance, which can be detected when it arrives at another point in the vascular system.
movement in a regular or circuitous course, returning to the point of origin, as the circulation of the blood through the heart and blood vessels. See also circulatory system.
circulation in the normal direction of flow.
is maintained in cardiopulmonary arrest by cardiac compression.
circulation carried on through secondary channels after obstruction of the principal channel supplying the part.
that within the coronary vessels, which supply the muscle of the heart.
cutaneous vessels are innervated by sympathetic adrenergic vasoconstrictor fibers; vasodilation is an important mechanism for losing heat after the body has been warmed.
the cycle in which bile salts and other substances excreted by the liver in the bile are absorbed by the intestinal mucosa and returned to the liver via the portal circulation.
circulation of blood outside the body, as through a hemodialyzer or an extracorporeal circulatory support unit.
circulation of blood through the body of the fetus and to and from the placenta through the umbilical cord. See also fetal circulation.
includes the hepatic arterial blood supply and the supply from the portal vein; drainage is via the hepatic veins to the caudal vena cava.
the circulation of the dam during pregnancy, including especially that of the uterus.
circulation in the newborn immediately after birth; the umbilical vessels contract forcing blood into the fetal veins; the foramen ovale closes, the ductus arteriosus narrows and eventually closes at day 1 to 2 after birth.
consists of the uveal and retinal blood vessels supported by the aqueous humor and vitreous body.
consists of the umbilical arteries, the vessels of the placenta proper and the umbilical veins; approximates the fetal corporeal circulation in volume.
a general term denoting the circulation of blood through larger vessels from the capillaries of one organ to those of another; applied especially to the passage of blood from the gastrointestinal tract, pancreas and spleen through the portal vein to the liver.
the flow of blood from the right ventricle through the pulmonary artery to the lungs, where carbon dioxide is exchanged for oxygen, and back through the pulmonary vein to the left atrium. See also pulmonary circulation.
flow of blood through the splenic artery and arterioles to either the capillaries, e. g. white pulp, or the highly permeable sinuses of the red pulp. Splenic venous blood drains into the portal vein and passes through the liver before re-entering the general circulation.
the flow of blood from the left ventricle through the aorta, carrying oxygen and nutrient material to all the tissues of the body, and returning through the superior and inferior venae cavae to the right atrium.
the time required for blood to flow between two given points. It is determined by injecting a substance into a vein and then measuring the time required for it to reach a specific site.