The ________ phase of muscle contractions occurs as AChE inactivates ACh and calcium ions are returned to the sarcoplasmic reticulum.

A) myogram
B) latent period
C) relaxation
D) contraction phase

AChE

Acetylcholinesterase, an enzyme that breaks down acetylcholine, a neurotransmitter, in the synapse, terminating the signal between nerves.

Relaxation Phase

The phase in the cardiac cycle or muscle contraction where the muscle returns to its initial state of relaxation.

Sarcoplasmic Reticulum

A network of tubules and sacs in muscle cells that store and regulate calcium ions, crucial for muscle contraction.