During the night, which two types of sleep alternate with each other in cycles that take approximately 90 minutes?
A) alpha sleep and delta sleep
B) Stage 1 and Stage 2 sleep
C) REM and NREM sleep
D) relaxed sleep and alert sleep

Question

Quizplus · Accepted Answer

During the night, REM (rapid eye movement) and NREM (non-rapid eye movement) sleep alternate with each other in cycles that take approximately 90 minutes. This cycle repeats several times throughout the night. REM sleep is characterized by rapid eye movements, muscle paralysis and vivid dreams, while NREM sleep is divided into 4 stages and is characterized by slow brain waves, reduced muscle activity and deep relaxation.

During the Night, Which Two Types of Sleep Alternate with Each