MCAT Biology Question 104: Answer and Explanation
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Question: 104
14. A person has a heart attack that primarily affects the wall between the two ventricles. Which portion of the electrical conduction system is most likely affected?
- A. AV node
- B. SA node
- C. Bundle of His
- D. Left ventricular muscle
Correct Answer: C
Explanation:
The cardiac conduction system starts at the SA node, which is located near the top of the right atrium, and continues down to the AV node, which is located between the two AV valves. The bundle of His is located within the wall between the ventricles, and is likely to be affected if the wall between the ventricles has been damaged by a heart attack. This may affect the left ventricle, but the left ventricle is not part of the cardiac conduction system.