During muscle contractions,
A) the sarcomeres shorten.
B) the actin filaments slide over the myosin filaments.
C) the actin filaments move toward the middle of the sarcomere during contraction and away on relaxation.
D) the muscle fibers thicken.
E) all of these occur.

Question

Quizplus · Accepted Answer

All of these occur during muscle contractions. The sarcomeres shorten as the actin filaments slide over the myosin filaments. The actin filaments move toward the middle of the sarcomere during contraction and away on relaxation. And the muscle fibers thicken as they contract.

During Muscle Contractions