ESS2001 Physiology Chapter 8 exphys

ESS2001 Physiology Chapter 8 exphys Accumulation of metabolic by-products in muscle (H+, CO2, heat) leads to a. vasoconstriction b. vasodilation c. sympathetic activation d. reduced muscle blood flow - ANSWER b. vasodilation VO2max is likely to be limited by a. substrate availability b. H+ ion accumulation c. cardiac output d. all of these - ANSWER c. cardiac output During moderate exercise in the heat, which vascular beds receive the most blood flow? a. muscle, splanchinic (gut) b. muscle, renal (kidneys) c. muscle, skin d. muscle, brain - ANSWER c. muscle, skin Hyperventilation causes a. an increase in oxygen b. an increase in carbon dioxide c. a decrease in oxygen d. a decrease in carbon dioxide - ANSWER d. decrease in carbon dioxide Which of the following will decrease stroke volume? a. increased preload b. increased contractility c. increased Ca2+ concentrations d. increased afterload - ANSWER d. increased afterload If the ventilatory equivalent for oxygen starts to increase and at the same time the ventilatory equivalent for carbon dioxide does not increase, this means that a. aerobic metabolism is increasing b. ventilation is becoming more efficient c. anaerobic metabolism is increasing d. ventilation is not meeting oxygen demands of the body - ANSWER c. anaerobic metabolism is increasing The mechanism that underlies preload's effects on stroke volume is the a.Frank-Starling mechanism b. Hering-Breuer mechanism c. Willis mechanism d. end-diastolic mechanism - ANSWER a. Frank-Starling mechanism Which one of these increases in direct proportion to exercise intensity? a. diastolic blood pressure b. venous oxygen content c. systolic blood pressure d. arterial oxygen content - ANSWER c