Physiology of sleep

Question 1

What are the symptoms of insomnia?

Answer 1

Delayed Sleep Onset
Early Morning Wake-ups
Unrefreshing sleep
Trouble maintaining sleep

insomnia is a symptom not a disorder

Question 2

What are the types of insomnia?

Answer 2

Transient 3 weeks (medical evaluation)

Question 3

What is useful for chronic insomnia?

Answer 3

Cognitive behavioral therapy -

Pharmacy therapy not useful only in select cases

Question 4

What are the stages of sleep?

Answer 4

Stage 1: transition between awake and asleep
Stage 2: Most time spent in this stage
Stage 3,4: Deep delta wave sleep occurs mostly early in the night

All four stages repeat in ultradian rhythm of 90 mins (4-5 per night).

Question 5

What is the arousal pathway of the sleep-wake cycle?

Answer 5

An ascending pathway to the thalamus (the pedunculopontine and laterodorsal tegmental nuclei (PPT/LDT). uses NTs; Cholergenic,

Locus coureleus
NTs:aminergic, Orexin

Question 6

What is the sleep promoting pathway?

Answer 6

• Ventrolateral preoptic nucleus (VLPO) within anterior hypothalamus PROMOTES SLEEP

NT: GABA- inhibits serotonin, norepinephrine, histamine, acetylcholine-producing interneurons

Question 7

What i the role of Melatonin?

Answer 7

Melatonin (hormone of darkness)
Secreted from pineal gland during 
     darkness-- indirectly feedbacks to SCN.
High levels secreted prior to sleep.
Levels low during wakefulness.