CVS and RESPI to exercise

What is the main role of the A-vO2 difference during exercise?

What happens to plasma volume during the first 5 minutes of exercise?

• Increases rapidly

• Remains stable

• Decreases rapidly

• Decreases gradually

What triggers an increase in coronary blood flow during exercise?

• Decrease in perfusion pressure

• Coronary vasoconstriction

• Increase in sympathetic nervous system stimulation

• Decrease in myocardial oxygen use

How does vasodilation in active muscles affect blood flow?

• Decreases blood flow

• Increases resistance

• Increases blood flow

• Decreases oxygen availability

Which type of muscle fibers are highly oxidative and fatigue-resistant?

• Fast-twitch fibers

• Slow-twitch fibers

• FTb fibers

• FTa fibers

At rest, approximately what percentage of oxygen is extracted from each unit of blood crossing myocardial capillaries?

• 25%

• 50%

• 70-80%

• 90%

How is blood flow redistributed during exercise?

• Away from active skeletal muscles

• Towards splanchnic organs

• Towards the skin and active skeletal muscles

• Away from the skin

What happens to pulmonary ventilation during the initial phase of exercise?

• Decreases gradually

• Remains unchanged

• Increases almost immediately

• Decreases immediately

During exercise, what percentage of cardiac output is directed to active skeletal muscles and skin?

• 20%

• 40%

• 60%

• 80%

Which type of muscle fiber has the lowest oxidative capacity?

• Slow-twitch fibers

• Fast-twitch FTa fibers

• Fast-twitch FTb fibers

• Slow-twitch Type II fibers