Cardiac Output & Exercise Physiology Quiz

Cardiac Output and Exercise

• Cardiac output initially increases during light to moderate-intensity exercise due to higher oxygen demand by muscles.
• This elevation ensures that more blood is pumped from the heart, delivering nutrients and oxygen efficiently.

Stroke Volume Increase

• Stroke volume rises during light to moderate dynamic exercise for several reasons:
  • Enhanced venous return occurs, aided by muscle contractions and respiratory movements, facilitating greater blood flow to the heart.
  • Increased contractility of the heart muscle leads to more effective pumping with each beat, improving stroke volume.

Heart Rate During Physical Activity

• Heart rate increases in response to physical activity, primarily driven by:
  • Activation of the sympathetic nervous system, which releases adrenaline and increases heart rate.
  • Demand for increased blood flow to active muscles during exercise, necessitating a faster heart rate for adequate oxygen transport.

Diastolic Blood Pressure Response

• Diastolic blood pressure typically remains stable or may decrease during light to moderate dynamic exercise as vascular resistance lowers.
• Vasodilation occurs in active muscle groups, allowing blood vessels to widen and decrease resistance against blood flow.

Systolic Blood Pressure Increase

• Systolic blood pressure rises during light to moderate dynamic exercise due to:
  • Increased cardiac output with a higher volume of blood being ejected from the heart.
  • Elevated arterial pressure as the heart works harder to supply working muscles with oxygen-rich blood.