Cardiovascular Physiology Flashcards
7 cards from real ACSM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Cardiovascular Physiology flashcards as text
Which vessel type has the greatest cross-sectional area and the slowest blood velocity?
Answer: Capillaries
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.
In the context of exercise physiology, which statement about the arteriovenous oxygen difference (a-vO₂ diff) is correct?
Answer: It widens progressively with increasing exercise intensity
The a-vO₂ difference widens as exercise intensity increases because working muscles extract more oxygen from arterial blood, lowering mixed venous PO₂.
Which component of blood pressure regulation is primarily controlled by the kidneys?
Answer: Long-term blood volume via renin-angiotensin-aldosterone system
The kidneys regulate long-term blood pressure through the renin-angiotensin-aldosterone system, which controls sodium retention and blood volume.
What is the approximate ejection fraction at rest in a healthy individual?
Answer: 50–70%
Normal resting ejection fraction is approximately 55–70%, reflecting the proportion of end-diastolic volume ejected with each heartbeat.
Which ion is primarily responsible for the rapid depolarization phase (Phase 0) of the cardiac action potential in ventricular myocytes?
Answer: Sodium (Na⁺) influx through fast channels
Phase 0 depolarization in ventricular cardiomyocytes is caused by rapid Na⁺ influx through voltage-gated fast sodium channels.
During submaximal steady-state exercise, what happens to total peripheral resistance (TPR)?
Answer: TPR decreases due to vasodilation in active muscle beds
TPR decreases during submaximal exercise because vasodilation in active skeletal muscle exceeds sympathetic vasoconstriction in non-active beds.
Which term describes the ventricular pressure that must be overcome for the heart to eject blood?
Answer: Afterload
Afterload is the resistance the ventricle must overcome to eject blood, largely determined by systemic vascular resistance and aortic pressure.