Which of the following describes a muscle contraction's four-step process?
A) Coupling,contraction,relaxation,excitation
B) Contraction,relaxation,excitation,coupling
C) Relaxation,excitation,coupling,contraction
D) Excitation,coupling,contraction,relaxation

Question

Quizplus · Accepted Answer

The process of muscle contraction starts with excitation, where a signal is sent to the muscle fiber from the nervous system. This is followed by coupling, where the signal triggers the release of calcium ions, which bind to the muscle fibers. This leads to contraction, where the muscle fibers generate force and shorten. Finally, relaxation occurs when the calcium ions are pumped back into the sarcoplasmic reticulum, allowing the muscle fibers to relax and return to their original length. Therefore, the correct sequence is excitation, coupling, contraction, and relaxation, which is described in answer choice D.

Which of the Following Describes a Muscle Contraction's Four-Step Process