AP PSYCHOLOGY

Detailed explanation-1: -Stage 2. During stage 2, or N2, the body enters a more subdued state including a drop in temperature, relaxed muscles, and slowed breathing and heart rate. At the same time, brain waves show a new pattern and eye movement stops.

Detailed explanation-2: -Brain temperature falls in non-REM sleep and then rises in REM sleep that typically follows.

Detailed explanation-3: -Stage 2. Stage 2 NREM sleep sees a continued slowing of heartbeat, breathing, muscle activity, and eye movements. During this stage, you also experience a reduction in body temperature. Throughout the course of the night, you spend about half the time in stage 2 sleep.

Detailed explanation-4: -Stage 4: REM sleep This stage first happens about 90 minutes after you fall asleep. Your eyes move quickly from side to side during REM sleep. In REM sleep, your brain waves and eye movements increase. Your heart rate and breathing also speed up.

Detailed explanation-5: -Stage 2: This period of light sleep features periods of muscle tone (muscles partially contracting) mixed with periods of muscle relaxation. Your eye movement stops, heart rate slows and body temperature decreases. Brain waves become slower.