Page 20, O2 Uptake, Exercise & Cor. Circ., Dr. D. Penney
Coronary Circulation (continued..)
CBF is regulated in a number of ways: Factors intrinsic to the coronary bed affect resistance by changes in vascular tone, mediated by metabolic, neurologic, and pharmacologic factors. The epicardial and intramural coronary arteries are heavily innervated by sympathetic nerve endings (alpha-receptor, constrictive; beta-receptor, dilator) and may also have some parasympathetic (dilator) nerve endings.
Most importantly for the coronary circulation, there is autoregulation, whereby coronary flow is maintained nearly constant in the face of varying perfusion pressure. Finally, there are factors extrinsic to the vascular bed such as the compressive intramyocardial pressure during systole which result in the majority of flow occurring during diastole.
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