Question

Describe the human sleep cycle, including the four stages and REM sleep, and what happens in each.

Answer 1

Sleep begins in stage 1 and progresses into stages 2, and 3. ... Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stagesapproximately four or five times throughout the night. On average, we enter the REM stage approximately 90 minutes after falling asleep

Answer 2

Stage 1: One starts to drift to sleep.

Stage 2: There are bursts of brain activity, called "spindles".

Stage 3: Breathing decreases and there are no longer spindles on EEG recordings.

Stage 4: This stage is deep sleep, which appears on EEG recordings as "delta waves".

Stage 5, AKA REM: This is when dreaming occurs and the eyes move rapidly.

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