Stages of Sleep

Question 1

NREM Stage I

Answer 1

Person is in a transitional stage between wakefulness and sleep
Relaxed state but still somewhat aware of the surroundings
Involuntary muscle jerking may occur and awaken the person
Normally only lasts minutes
Aroused easily
5% of total sleep

Question 2

NREM Stage II

Answer 2

Person falls into a stage of sleep
Person can be aroused with relative ease
50%-55% of sleep

Question 3

NREM Stage III

Answer 3

Depth of sleep increases and arousal becomes increasingly difficult
10% of sleep

Question 4

NREM Stage IV

Answer 4

Greatest depth of sleep (delta sleep)
Arousal is difficult
Physiologic changes in the body include: slow brain waves, pulse and respiratory rate decreases, BP decreases, muscles are relaxed, metabolism slows and the body temp is low
10% of sleep

Question 5

REM Sleep

Answer 5

Eyes dart back and forth quickly
Small muscle twitching (such as on the face)
Large muscle immobility, resembling paralysis
respirations become irregular; sometimes interspersed with apnea
rapid or irregular pulse
blood pressure increases or fluctuates
increase in gastric secretions
metabolism increases, body temp increases
encephalogram tracings active
REM sleep enters from stage II of NREM sleep and reenters NREM sleep at stage II: arousal from sleep difficult
20%-25% of sleep