PHYS30005 Lecture Notes - Lecture 4: Constant Function, Cerebral Circulation, Partial Pressure

• School: University of Melbourne
• Department: Physiology
• Course: PHYS30005
• Professor: Professor

Document Summary

Determined by cardiac output (q) and oxygen extraction (cao2 cvo2) Map must be maintained for the brain: co x tpr. Active skeletal muscles at max exercise get close to 90% of cardiac output. Light-heavy exercise has increase in skin blood flow higher intensities is reduction in skin blood flow as we approach maximal cardiac output: competition b/w muscle and skin and heart and brain. Splanchnic regions and kidney regions are vasoconstricted. Largely similar b/w sedentary and athletic group, except athlete can get to much higher vo2: largely due to ability to achieve higher co, most of increase in max vo2 is due to increase in max co. Reduction in heart rate in athletic group. Some studies have suggested that sv might continue to increase until levelling off at higher intensity (specifically in athletics: sv levels off because increase in hr -> diastolic filling time becomes limiting - > heart not able to be optimally filled at very high heart rates.