Cardiac function curve Contractile Afterload Normal Contractility Afterload ATRIAL PRESSURE
Cardiac function curve
Venous function A fundamental determinant of cardiac performance Maximal venous return is described by the equation (Pmc-Pa)/Rv Pmc: the mean circulatory pressure Pa: the right atrial pressure RV: the venous resistance
Venous Function • A fundamental determinant of cardiac performance • Maximal venous return is described by the equation: (Pmc-Pa)/Rv • Pmc : the mean circulatory pressure • Pa : the right atrial pressure • Rv : the venous resistance
Microvascular function Effective tissue perfusion requires intact microvascular function Match blood flow to areas of highest metabolic activity Intrinsic control of blood flow: endothelial stretch receptors metabolic activity Extrinsic control of blood flow: autonomic nervous system
Microvascular Function • Effective tissue perfusion requires intact microvascular function. • Match blood flow to areas of highest metabolic activity. • Intrinsic control of blood flow: endothelial stretch receptors, metabolic activity • Extrinsic control of blood flow: autonomic nervous system
Compensatory mechanism
Compensatory mechanism
Baroreceptors and chemoreceptors Cardioregulatory center and chemoreceptors in medulla oblongata Sensory nerve fibers Baroreceptors wall of interna Carotid body nerve Baroreceptors in aorta 2 Parasympathetic nerve fibers SA node Sympathetic nerve fibers nerve fib adrenal Adrenal medulla Epinephrine and norepinephrine
Baroreceptors and chemoreceptors