When Acetylcholine Binds to Receptors on the Motor End Plate

Question

When acetylcholine binds to receptors on the motor end plate, ________ occurs immediately.
A) vesicular enzymatic activity
B) cross-bridge formation
C) ATP-myosin binding
D) an action potential
E) myosin head pivoting

Accepted Answer

When acetylcholine binds to receptors on the motor end plate, an action potential is immediately triggered. This leads to the release of calcium ions from the sarcoplasmic reticulum, which ultimately leads to myosin head pivoting and the generation of force and contraction in the muscle fibers. Vesicular enzymatic activity, cross-bridge formation, and ATP-myosin binding are all important steps in muscle contraction, but they occur after the initial action potential is triggered.