What stage of sleep is the initial phase of deep sleep?
A) Stage 1 nonrapid eye movement (NREM)
B) Stage 3 NREM
C) Stage 5 NREM
D) Rapid eye movement (REM) sleep

Question

Quizplus · Accepted Answer

Stage 3 NREM, also known as slow-wave sleep, is the initial phase of deep sleep. This stage is characterized by delta waves in the brain and is important for physical restoration and healing. Stage 1 NREM is considered light sleep, and both REM sleep and Stage 5 NREM are not part of deep sleep.

What Stage of Sleep Is the Initial Phase of Deep