How do the muscle cells help in movement?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. The contraction and relaxation of these cells result in movement.
Muscle cells contract and relax to move the body, and this process is made possible by the chemical interactions of two proteins, actin and myosin:
Muscle contraction
- The nervous system sends a signal to the muscle fibers, which causes the muscle fibers to shorten. This happens when the following steps occur:
- An action potential travels along a motor nerve to the muscle fibers
- The nerve releases acetylcholine (ACh) at the muscle fiber membrane
- ACh opens channels that allow sodium ions to flow into the muscle fiber