Question

Which descriptions are not correct about the fatigue of muscles?

A. During sustained isometric contractions, the muscle may be starved of oxygen
B. Lactic acid accumulates as oxygen-dependent metabolic processes take place
C. Depletion of muscle glycogen is one of the causes of fatigue in endurance athletes
D. None

Answer 1

Muscle fatigue occurs when a muscle can no longer contract in response to signals from the nervous system. Several factors contribute to muscle fatigue, including reduced ATP reserves, lactic acid buildup, and disruptions in ion flow. Long periods of sustained exercise can also lead to damage in the muscle cells.

Step-by-step explanation:

Muscle fatigue occurs when a muscle can no longer contract in response to signals from the nervous system. ATP is needed for normal muscle contraction, and as ATP reserves are reduced, muscle function may decline. Lactic acid buildup may lower intracellular pH, affecting enzyme and protein activity. Imbalances in Na+ and K+ levels as a result of membrane depolarization may disrupt Ca flow out of the SR. Long periods of sustained exercise may damage the SR and the sarcolemma, resulting in impaired Ca regulation.