Which of the following best describes the length-tension relationship in skeletal muscle?
A. Tension increases with sarcomere length until it reaches a maximum at full extension.
B. Tension is independent of the length of the sarcomere.
C. Tension decreases as sarcomeres are in resting length.
D. Tension is maximal when the sarcomeres are at their normal resting length.
Answer (2)
The question is about the length-tension relationship in skeletal muscle.
Analyze each option to determine the correct statement.
Option E, stating that tension is maximal when sarcomeres are at their normal resting length, is the correct answer.
Therefore, the answer is \boxed{E}.
Explanation
Understanding the Question The question asks us to identify the statement that accurately describes the length-tension relationship in skeletal muscle. This relationship explains how the force a muscle can generate is affected by its length at the time of contraction.
Analyzing the Options Let's analyze each option:
Option A: Tension increases with sarcomere length until it reaches a maximum at full extension. This is incorrect because tension decreases beyond the optimal length due to reduced overlap between actin and myosin filaments.
Option C: Tension is independent of the length of the sarcomere. This is incorrect because the length of the sarcomere directly affects the number of cross-bridges that can form, thus influencing tension.
Option D: Tension decreases as sarcomeres are in resting length. This is incorrect because at resting length, sarcomeres are typically at an optimal length for tension generation.
Option E: Tension is maximal when the sarcomeres are at their normal resting length. This is the correct answer. The resting length of a sarcomere is where the overlap between actin and myosin filaments is optimal, allowing for the greatest number of cross-bridges to form and thus maximal tension.
Determining the Correct Answer Based on our analysis, the statement that best describes the length-tension relationship in skeletal muscle is that tension is maximal when the sarcomeres are at their normal resting length.
Examples
Understanding the length-tension relationship is crucial in sports science and rehabilitation. For example, when designing exercises, trainers consider this relationship to optimize muscle activation and prevent injuries. Knowing that muscles generate maximum force at their resting length helps in creating effective strength training programs and in understanding how different joint angles affect muscle performance. This principle also applies in physical therapy, where therapists aim to restore optimal muscle length to maximize function and reduce pain.
The correct option that best describes the length-tension relationship in skeletal muscle is D: tension is maximal when the sarcomeres are at their normal resting length. This is because at this length, the overlap between actin and myosin filaments is optimal, allowing for maximum tension generation. Proper understanding of this concept is crucial in fields like sports science and rehabilitation.
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