This image depicts the sleep cycles over the course of a typical night. In which stage does the brain become much more active, and heart rate, blood pressure, and respirations shift up and down, sometimes extremely?

A) stage 1 NREM
B) stage 2 NREM
C) REM sleep
D) stage 4 NREM

Question

This image depicts the sleep cycles over the course of a typical night. In which stage does the brain become much more active, and heart rate, blood pressure, and respirations shift up and down, sometimes extremely?

A) stage 1 NREM 
B) stage 2 NREM 
C) REM sleep 
D) stage 4 NREM

Quizplus · Accepted Answer

During REM sleep, the brain becomes much more active, and there are significant shifts in heart rate, blood pressure, and respirations. This is the stage where most dreaming occurs.

This Image Depicts the Sleep Cycles Over the Course of a Typical