Sleep and Awake

Pertanyaan pengantar

• Apa itu tidur?
• Kenapa kita harus tidur?
• Pada waktu kapan kita biasanya kita tidur?

Brain Game

Sleep On THE physiological System

• Endogenous Circadian Rhythm
• Biological Clock
• Mechanism of Biological Clock

Endogenous Circadian Rythm

• Circadian rhythms are the regular, daily cycles of biological processes or activities, including the regular and predictable variation in the levels of many circulating hormones, ions and the control of sleep and wakefulness. Circadian rhythms are controlled centrally by the suprachiasmatic nucleus, and are most strongly influenced by light.

Biological Clock

• Zeitgeber
• Sleep Deprivation: Jet lag, Shift Work
• Hibernation

Mechanisms of Biological Clock

• SCN
• Melatonin and Cortisol

Stages of Sleep

• EEG measures electrical potentials * potentials are not average of all neuron activity, an objective measure of sleep or wakefulness
• Stage 1 * irregular, jagged, low-voltage waves * activity high but declining
• Stage 2 * sleep Spindles, burst of 12-14 Hz waves lasting at least half a second * K-complex: sharp high-amplitude negative wave followed by a smaller, slower positive wave
• Stage 3 & 4, slow-wave sleep * start of large amplitude waves at least half second * half of activity is slow-wave by stage 4 * deepest sleep, least responsive to stimuli, hard to awake After about 60-90 minutes, we cycle back from 4 to 3 to 2 and then to rapid eye movement sleep (REM) repeats all night early evening: more stages 3 - 4 and less REM late evening: more REM and less stages 3 - 4
• After about 60-90 minutes, we cycle back from 4 to 3 to 2 and then to rapid eye movement sleep (REM) * repeats all night * early evening: more stages 3 - 4 and less REM * late evening: more REM and less stages 3 - 4

Rapid Eye Movement (REM)

• Irregular, low-voltage, fast EEG waves Rapid eye movements and postural muscle paralysis Penile erection and vaginal moistening Irregular heart rate, blood pressure and breathing rates Dreams reported by 80-90% of persons awakened during REM likely to have more complicated plots and striking visual imagery than non-REM stage dreams
• Rapid eye movements and postural muscle paralysis Penile erection and vaginal moistening Irregular heart rate, blood pressure and breathing rates Dreams reported by 80-90% of persons awakened during REM likely to have more complicated plots and striking visual imagery than non-REM stage dreams
• Penile erection and vaginal moistening Irregular heart rate, blood pressure and breathing rates Dreams reported by 80-90% of persons awakened during REM likely to have more complicated plots and striking visual imagery than non-REM stage dreams
• Irregular heart rate, blood pressure and breathing rates Dreams reported by 80-90% of persons awakened during REM likely to have more complicated plots and striking visual imagery than non-REM stage dreams
• Dreams reported by 80-90% of persons awakened during REM * likely to have more complicated plots and striking visual imagery than non-REM stage dreams
• Research: * REM associated with loose associations (e.g., thief-wrong) possible explanation for why dreams seem to jump around in haphazard, complicated way * non-REM associated with strong associations (e.g., long-short) and simpler dreams

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Sleep Disorders

• Sleep Apnea
• Narcolepsy
• Periodic Limb Movement Disorder
• REM Behaviour Disorder

Sleep and Dream