During REM (R) sleep,your skeletal muscles are relaxed because messages from the motor cortex are blocked by the

A) brainstem.
B) hypothalamus.
C) suprachiasmatic nucleus.
D) amygdala.

Motor Cortex

A region of the cerebral cortex involved in planning, controlling, and executing voluntary motor functions.

Brainstem

The part of the brain connecting the spinal cord with the forebrain and cerebrum, responsible for autonomic functions necessary for survival.

Suprachiasmatic Nucleus

A region in the brain responsible for controlling circadian rhythms through the regulation of sleep-wake cycles and hormonal activities.