Non-REM sleep

1. EEG patterns divide slow wave (non REM) sleep into four stages: Stage l: α waves, 8-1 2 Hz, low amplitude, moderate frequency, similar to drowsy wakefulness;

2. Stage Il: slower frequency, higher amplitude, plus bursts of sleep spindles and episodes of K complexes;

3. Stage Ill: Appearance of δ waves, 1-2 Hz, large amplitude;

Features of Non-REM sleep:

• Brain activity < awake by ±30%;

• Muscle tone is maintained;

• Mainly parasympathetic;

  • Decreased heart rate & BP;

  • Respiration is regular;

  • Increased GIT motility

  • Body temperature is maintained

• Arousal:

  • Spontaneous is difficult

  • By external stimulus is easy

• Low association with dreaming.