Question

During REM sleep, the motor cortex is activated, but the body is very still. This pattern occurs because through the brain stem of motor activation.

a) Inhibits signals to the muscles
b) Increases signals to the muscles
c) Causes muscle spasms
d) Has no effect on muscle activity

Answer 1

During REM sleep, the motor cortex is activated, but the body is very still due to signals from the brain stem inhibiting signals to the muscles. This leads to paralysis of the voluntary muscles.

Step-by-step explanation:

During REM sleep, the motor cortex is activated, but the body is very still because signals from the brain stem inhibit signals to the muscles. This leads to a state of paralysis of the voluntary muscles, while the muscles responsible for circulation and respiration remain active. This combination of high brain activity and lack of muscle tone is why REM sleep is often referred to as paradoxical sleep.