BMS 420 Lecture Notes - Cerebral Edema, Grey Matter, Cardiac Output
Document Summary
Acetylcholine is a probe for stimulating ec (endothelial cell) production of no . Flow reversal can occur during isovolumetric contraction phase. Higher partial pressure of o2 in coronary sinus. Neural and neurohumoral factors also affect coronary blood flow. Cardiac sympathetic nerve simulation vasoconstriction but the increased metabolites which result cause vasodilation. Likewise with adrenergic blockage, vasoconstriction will occur. And adrenergic receptor activation will cause vasoconstriction and vasodilation respectively. Stimulation of the vagus nerve will cause vasodilation (intracoronary administration of. Ach causes dilation too) but since the metabolism (heart rate/inotropy) is also less, vasoconstriction overrides the tendency to vasodilate. Coronary blood flow increases fairly linearly with myocardial metabolism ( sv; afterload; hr) Normally, o2 extraction is 50 75% vs. 25% for general circulation. A decrease in the supply:demand ratio will cause vasodilator generation and the reverse happens with an increase in ratio. Arterial o2 content, coronary blood flow myocardial o2 supply.
