The relations between microvascular structure and oxygen supply.
The current theories of microcirculatory control require a higher command center to maintain tissue homeostasis. The theory of arteriolar vasodilation generates conflicting results by increasing the flow and the capillary hydrostatic pressures. A new theory, recently suggested to account for local tissue flow control, applies a blinking mechanism of open capillaries, whereby alternating circulatory modes increase flow to specific tissue regions, without inducing a higher control center. The mechanism is evaluated here mathematically by examining the oxygen demand, supply and local tissue concentration of oxygen. It is shown that this theory explains how periods of oxygen debts are compensated by increased flow with changes in the operation mode. The results show that there is a direct relation between the tissue microvascular complexity and the capability of the specific tissue to withstand periods of oxygen deficit.
Dinnar
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Department of Biomedical Engineering, Technion-IIT, Haifa, Israel.
D000818:Animals; D002196:Capillaries / Q000033:anatomy & histology / Q000502:physiology; D008833:Microcirculation / Q000033:anatomy & histology*; D008954:Models, Biological; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D013997:Time Factors
D010100:Oxygen