Cardiovascular responses

What are the three major effects of the cardiovascular response to exercise?

Increased heart rate, increased stroke volume, and redistribution of blood flow to active muscles.

How is cardiac output regulated during exercise?

Cardiac output is regulated by the autonomic nervous system (PNS and SNS), venous return, and mean arterial pressure (MAP). Factors contributing to an increase in cardiac output include increased heart rate and stroke volume.

What is the formula for mean arterial pressure (MAP) and how is it maintained during exercise?

MAP = Q x TPR; it is maintained by adjusting cardiac output (Q) and total peripheral resistance (TPR) during exercise.

How does blood flow relate to vascular resistance and pressure?

Blood flow is inversely related to vascular resistance; as resistance increases, blood flow decreases. MAP is maintained through changes in Q and TPR.

How is arteriole diameter regulated during exercise and what is its effect on resistance?

Arteriole diameter is regulated by local metabolic factors and neural control, affecting resistance to blood flow according to the formula R=1/r^4.

What is the difference between local and central control of blood distribution during exercise?

Local control involves the regulation of blood flow to specific tissues based on metabolic needs, while central control refers to overall blood distribution managed by the autonomic nervous system.

How does exercise intensity affect renal blood flow?

As exercise intensity increases, renal blood flow typically decreases due to prioritization of blood flow to active muscles.

What changes occur in heart rate, stroke volume, and cardiac output during prolonged submaximal exercise?

Heart rate increases while stroke volume may decrease over time, especially in hot, humid environments, leading to a steady state in cardiac output.

How do heart rate and blood pressure responses differ between arm work and leg work?

Arm work typically results in a higher heart rate and blood pressure response compared to leg work due to the smaller muscle mass and higher relative intensity.

What role does central command play in cardiovascular responses to exercise?

Central command initiates cardiovascular adjustments in anticipation of exercise, while peripheral feedback provides information from working muscles to fine-tune these responses.

How do the three major effects of the cardiovascular response to exercise work together?

They work together to increase blood flow to active muscles by enhancing cardiac output and redistributing blood flow from non-essential areas.

What factors contribute to an increase in cardiac output during exercise?

Factors include increased heart rate, increased stroke volume, and enhanced venous return.

What is the significance of calculating reasonable values for cardiac output (Q) at rest and during exercise?

Calculating Q helps assess cardiovascular fitness and the efficiency of the heart in delivering blood during different intensities of exercise.

How does the body maintain MAP during changes in cardiac output and vascular resistance?

The body adjusts heart rate and vascular resistance through neural and hormonal mechanisms to keep MAP stable despite fluctuations in Q and TPR.

What is the impact of a hot, humid environment on heart rate and stroke volume during exercise?

In a hot, humid environment, heart rate may increase to maintain cardiac output, while stroke volume may decrease due to increased sweating and reduced blood volume.

How do trained and untrained individuals differ in their cardiovascular responses to progressive exercise?

Trained individuals typically exhibit a lower resting heart rate, higher stroke volume, and more efficient cardiovascular responses compared to untrained individuals.