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

REM sleep is characterized by high brain activity, rapid eye movements, and fluctuations in heart rate, blood pressure, and respiration. This is the stage of sleep where most vivid dreaming occurs.

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