PS101 Study Guide - Final Guide: Slow-Wave Sleep, Hypnagogia, Delta Wave
Document Summary
Circadian rhythms: brain & environment: circadian rhythms (biological clock) are patterns of sleep-wake cycles that in human beings roughly correspond to periods of daylight and night, circadian rhythms regulated by suprachiasmatic nuclei (scn) Scn is a small group of neurons in the hypothalamus responsible for coordinating the many rhythms of the body. Scns are the master control centre for your body"s internal clock and sleep-wake rhythm. Scn neurons notice change of day to night and directs the pineal gland to secrete melatonin, triggering sleepiness. Circadian rhythms: neurons in scn - active during daytime. Inhibits melatonin secretion: neurons in scn become inactive at night, allows melatonin secretion to increase, melatonin promotes relaxation and sleepiness. Isolation studies in complete darkness show 24. 2 to 24. 8 hours, back to 24 hours when returned to normal living conditions: disruptions of circadian rhythms. Jet lag: night-shift work, seasonal effective disorder. Sleep & dreaming: circadian rhythms - promote readiness for sleep.
