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Ch. 18 The Cardiovascular System: The Heart
Hoehn - Marieb Human Anatomy & Physiology, 12th edition
Hoehn, Haynes, Abbott12th EditionMarieb Human Anatomy & PhysiologyISBN: 9780138242732당신이 사용하는 게 아니라요?교과서 변경
18장, 문제 10

The refractory period of cardiac muscle is much longer than that of skeletal muscle. Why is this a desirable functional property?

검증된 단계별 안내
1
Step 1: Understand what the refractory period is — it is the time during which a muscle cell cannot be re-excited after an action potential has occurred.
Step 2: Recognize that cardiac muscle cells have a much longer refractory period compared to skeletal muscle cells, meaning they remain unresponsive to new stimuli for a longer time.
Step 3: Consider the functional importance of this long refractory period in cardiac muscle — it prevents the muscle from undergoing tetanus, which is a sustained contraction.
Step 4: Realize that preventing tetanus in cardiac muscle is crucial because the heart needs to relax between beats to allow chambers to fill with blood properly.
Step 5: Conclude that the long refractory period ensures rhythmic, coordinated contractions and proper pumping function of the heart, which is essential for maintaining effective blood circulation.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
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2m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Refractory Period

The refractory period is the time after an action potential during which a muscle cell cannot be re-excited. It ensures that the muscle has time to contract and relax before the next stimulus, preventing continuous or premature contractions.
추천 영상:
06:26
Refractory Period

Cardiac Muscle Contraction

Cardiac muscle contractions are rhythmic and coordinated to pump blood effectively. A longer refractory period prevents tetanus (sustained contraction), allowing the heart chambers to fill and empty properly during each beat.
추천 영상:
4:53
Overview of Muscle Contraction

Functional Differences Between Cardiac and Skeletal Muscle

Skeletal muscle can sustain rapid, repeated contractions for movement, so it has a short refractory period. In contrast, cardiac muscle requires a longer refractory period to maintain a steady heartbeat and avoid arrhythmias, ensuring efficient blood circulation.
추천 영상:
2:46
Structure of a Skeletal Muscle Example 2