Sleep

• sleep cycle is regulated by circadian rhythm which is driven by the suprachiasmatic nucleus in the hypothalamus
• suprachiasmatic nucleus is regulated by the environment( light)
• circadian rhythm controls nocturnal release of ACTH melatonin and prolactin and norepinephrine
• suprachiasmatic nucleus releases norepinephrine which stimulates pineal gland to release melatonin
• alcohol benzodiazepines and barbiturates decrease rem and N3
• norepinephrine decreases rem
• benzodiazepines can be used for night terrors and sleepwalking
• awake and eyes open is alert and active mental concentration appears as Beta waves on eeg (highest frequency lowest amplitude)
• awake with eyes closed appears as Alpha wave
• 
  

  N1: light sleep theta wave
• What occurs in Rem :

  • clitoral/penile swelling
  • increased o2 usage
  • rapid eye movements due to paramedian pontine occular center/conjugate gaze center
  • increased acetylcholine
  • memory processing function
  • dreaming and nightmares
• REM decreases in older adults and n3 decreases sleep latency increases and increased early awakenings
• rem latency decreases in depression and rem time increases and n3 decreases so repeated nightime awakenings early morning awakenings
• N2: deeper sleep bruxism occurs here sleep spindles and k complexes
• N3:night terrors and sleepwalking and bed wetting delta waves ( lowest frequency highest amplitude) deepest sleep stage