🏥 USMLE Exam Prep

An increase in preload, within physiological limits, primarily leads to an increase in stroke volume by which mechanism?

A Decreasing end-systolic volume
B Increasing myocardial contractility
C Decreasing afterload
D Activating the Frank-Starling mechanism

✓ Correct Answer: Option D

The Frank-Starling mechanism states that an increase in preload (end-diastolic volume) stretches cardiac muscle fibers, leading to a more forceful contraction and thus an increased stroke volume, ensuring that cardiac output matches venous return.

💡 Why is D) the correct answer?

The correct answer to the question "An increase in preload, within physiological limits, primarily leads to an increase in stroke volume by which mechanism?" is Option D: Activating the Frank-Starling mechanism.

The other options — A) Decreasing end-systolic volume, B) Increasing myocardial contractility, C) Decreasing afterload — are incorrect for this USMLE Exam Prep question. As explained above: The Frank-Starling mechanism states that an increase in preload (end-diastolic volume) stretches cardiac muscle fibers, leading to a more forceful contraction and thus an increased stroke volume, ens…

📚 About This USMLE Exam Prep Practice Question

This 2-level USMLE Exam Prep question from the Step 1 – Basic Sciences topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free USMLE Exam Prep practice test or use flashcards for spaced repetition review.

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