Final answer:
Muscle fatigue occurs when a muscle can no longer contract in response to signals from the nervous system. The reduced ability of the sarcoplasmic reticulum to release Ca²⁺ with neural stimulation can disrupt Ca²⁺ flow and contribute to muscle fatigue.
Step-by-step explanation:
Muscle fatigue occurs when a muscle can no longer contract in response to signals from the nervous system. Several factors have been correlated with decreased muscle contraction during fatigue, including reduced ATP reserves, lactic acid buildup, imbalances in ion levels, and damage to the sarcoplasmic reticulum (SR).
In the case of reduced ability of the SR to release Ca²⁺ with neural stimulation, this disruption in Ca²⁺ flow out of the SR can impact muscle contraction and contribute to fatigue.