Architecture of the Circulation, Dr. D. Penney
"Average time taken for a RBC (or injected dye*) to traverse the systemic & pulmonary circulations, and return to the starting point".
Circ. t (sec.) = Vasc. bed vol. between A & B (ml) / vol. flow, A to B (ml/sec)
Coronary route =10 sec.
Some routes = several minutes (extensive venous sinuses spleen, etc.)
Body average = 40 -60 sec. (vol. of the card. output circulated approx. once per min.)
Circulation time is decreased by exercise, arteriovenous shunting, reduced venous pooling.
Most of time is spent in the veins; thus, circulation time is more dependent on what happens in the veins than in the arteries, arterioles (i.e. vaso - venomotion)
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