Exercise Physiology (OY)

Which of the following is not a factor regulating stroke volume?

• Ventricular distensibility

• Ventricular contractibility

• Aortic pressure

• Aortic return

At rest, where is most of the blood volume distributed?

• Muscle

• Brain

• Internal organs

• Peripheral limbs

What is the a-vO2 difference during maximal exercise?

• 8 ml/100ml

• 12 ml/100ml

• 16 ml/100ml

• 20 ml/100ml

What mechanism drives the first phase of ventilation during an exercise bout?

• Anticipation and neural drive from central command

• Changes on PCO2 and arterial stretch

• Low circulating hydrogen ions

• Increased in heat production from muscle contraction

What is Exercise-induced arterial hypoxemia?

• A drop in PCO2 from poor ventilation

• Ventilation-perfusion mismatch from high stroke volume

• A drop in PO2 from poor ventilation

• Ventilation-perfusion mismatch from high cardiac output

What is the preferred source of energy for prolonged exercise?

• Muscle glycogen

• Muscle lipids

• Circulating glucose

• Circulating free fatty acids

At approximately which exercise intensity does the contribution of lipids and carbohydrates are equal?

• 10%

• 30%

• 50%

• 70%

• 90%

During maximal exercise (e.g. sprinting), how long does it take for ATP to be depleted?

• About 5 sec

• About 15 sec

• About 25 sec

• About 35 sec

• About 45 sec

What is the rate limiting enzyme of anaerobic glycolysis?

• Phosphofruktokinase

• Phosphohexo isomerase

• phosphoglycerate kinase

• pyruvate kinase

• none

What is the rate limiting enzyme of the krebs cycle?

• Citrate synthase

• Succinate dehydrogenase

• Malate dehydrogenase

• Isocitrate dehydrogenase

• none