ACSM-EP Cardiovascular Physiology 3

Question 1

Which vessel type has the greatest cross-sectional area and the slowest blood velocity?

Accepted Answer

Capillaries

Answer

Capillaries collectively have the greatest total cross-sectional area, which by continuity of flow results in the slowest blood velocity, facilitating gas and nutrient exchange.

Question 2

In the context of exercise physiology, which statement about the arteriovenous oxygen difference (a-vO₂ diff) is correct?

Accepted Answer

It widens progressively with increasing exercise intensity

Answer

The a-vO₂ difference widens as exercise intensity increases because working muscles extract more oxygen from arterial blood, lowering mixed venous PO₂.

Question 3

Which component of blood pressure regulation is primarily controlled by the kidneys?

Accepted Answer

Long-term blood volume via renin-angiotensin-aldosterone system

Answer

The kidneys regulate long-term blood pressure through the renin-angiotensin-aldosterone system, which controls sodium retention and blood volume.

Question 4

What is the approximate ejection fraction at rest in a healthy individual?

Accepted Answer

50–70%

Answer

Normal resting ejection fraction is approximately 55–70%, reflecting the proportion of end-diastolic volume ejected with each heartbeat.

Question 5

Which ion is primarily responsible for the rapid depolarization phase (Phase 0) of the cardiac action potential in ventricular myocytes?

Accepted Answer

Sodium (Na⁺) influx through fast channels

Answer

Phase 0 depolarization in ventricular cardiomyocytes is caused by rapid Na⁺ influx through voltage-gated fast sodium channels.

ACSM Practice Test

ACSM Practice Test

ACSM-EP Cardiovascular Physiology 3