The release of ________ to muscle cell receptors triggers muscle contractions.

A) ACh
B) serotonin
C) dopamine
D) adrenaline

Muscle Contractions

Muscle contractions refer to the tightening or shortening of muscles, which results in movement or maintenance of posture.

ACh

Short for Acetylcholine, a neurotransmitter in the body involved in many functions including muscle movement and memory.

Dopamine

A neurotransmitter in the brain associated with pleasure, movement, and the reward system.