What tells a muscle when to contract?

What tells a muscle when to contract?

Explanation:

(1) A message travels from the nervous system to the muscular system, triggering chemical reactions.

(2) The chemical reactions lead to the muscle fibers reorganizing themselves in a way that shortens the muscle--that’s the contraction.

(3) When the nervous system signal is no longer present, the chemical process reverses, and the muscle fibers rearrange again and the muscle relaxes.

The nervous system generates a signal, which triggers a muscle to contract

Explanation:

Genetic factors contributes to the formation of the dead zones is by their ability to expand their abilities that enables them to spread and contribute to the formation of the dead zones. These dead zones are made when the oxygen are low where it is necessarily important for the aquatic life, if the oxygen needed is depleted or too low, instead of supporting aquatic life, dead zones are created and factors contribute to these occurrences with their ability to expand.