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Peripheral Fatigue

Neuromuscular Junction: With neuromuscular junction there is a breakdown of ACh in getting to the motor end plate resulting in NO muscle contraction. The mechanism for this breakdown is not fully understood.
Two sites in muscle: At one site, the H+ ions interfere with calcium ions from binding to troponin. The interference PREVENTS the configuration shift of tropomyosin to reveal the active bindings sites. In the other site, the increase in acidosis (from the H+ ion accumulation) denatures (i.e., breakdown) the enzyme ATPase, inhibiting the splitting of ATP to ADP and Pi and energy. Remember, the H+ accumulation is coming from the hydrolysis of ATP during the exercise bout. The H+ comes from the water molecule (H2O).