Beta-blockers primarily act by:

A Increasing heart rate

B Blocking beta-adrenergic receptors, reducing heart rate, contractility, and blood pressure

C Increasing blood pressure

D Dilating bronchioles

✓ Correct Answer: Option B

Beta-blockers: antagonize beta-1 (cardiac) receptors → decreased HR, contractility, and AV conduction. Non-selective also block beta-2 (bronchial smooth muscle) → contraindicated in asthma.

💡 Why is B) the correct answer?

The correct answer to the question "Beta-blockers primarily act by:" is Option B: Blocking beta-adrenergic receptors, reducing heart rate, contractility, and blood pressure.

The other options — A) Increasing heart rate, C) Increasing blood pressure, D) Dilating bronchioles — are incorrect for this USMLE Exam Prep question. As explained above: Beta-blockers: antagonize beta-1 (cardiac) receptors → decreased HR, contractility, and AV conduction. Non-selective also block beta-2 (bronchial smooth muscle) → contraindicated in asthma.

📚 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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Beta-blockers primarily act by:

✓ Correct Answer: Option B

📚 About This USMLE Exam Prep Practice Question

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