Sleep and Sleep Sleep and Sleep DisordersDisorders

Neural Control of SleepNeural Control of Sleep

Sleep and waking Sleep and waking are different are different states of arousal.states of arousal.

Reticular Reticular activating system activating system controls this.controls this.

Decrease in Decrease in arousal is arousal is accompanied by accompanied by less cortical less cortical activity.activity.

Neural Control of SleepNeural Control of Sleep

Bodily cycles Bodily cycles (circadian (circadian rhythms) are rhythms) are controlled by part controlled by part of the hypo-of the hypo-thalamus.thalamus.

Pineal gland Pineal gland controls circulating controls circulating levels of melatoninlevels of melatonin—more light, less —more light, less melatonin.melatonin.

Biological ClockBiological ClockCircadian RhythmsCircadian Rhythms

Stages of SleepStages of Sleep

REM Sleep

Rapid Eye Movement (REM)SleepRapid Eye Movement (REM)Sleep

Eyes move rapidly.Eyes move rapidly. If awakened 90% report dreaming.If awakened 90% report dreaming. ParadoxicalParadoxical

Muscles relaxed.Muscles relaxed. Brain active.Brain active. Sometimes called active sleep.Sometimes called active sleep.

Seems to be necessary.Seems to be necessary. If insufficient, amount per night increases.If insufficient, amount per night increases.

Effects of REM DeprivationEffects of REM Deprivation

Sleep DisordersSleep Disorders

Sleep ApneaSleep Apnea

Most who Most who suffer from suffer from sleep apnea sleep apnea snore heavily.snore heavily.

All snorers do All snorers do not have sleep not have sleep apnea.apnea.

So what is it?So what is it?

Sleep ApneaSleep Apnea

Relaxation of Relaxation of sleep leads to sleep leads to blocking of airway.blocking of airway.

Person awakes Person awakes briefly, gasps, and briefly, gasps, and falls back to sleep.falls back to sleep.

May happen 100s May happen 100s of times per night.of times per night.

InsomniaInsomnia

Inadequate or poor Inadequate or poor quality sleep because quality sleep because of:of: Difficulty falling asleep.Difficulty falling asleep. Waking up frequently Waking up frequently

during the night with during the night with difficulty returning to difficulty returning to sleep.sleep.

Waking too early in the Waking too early in the morning.morning.

Unrefreshing sleep.Unrefreshing sleep.

InsomniaInsomnia More common for:More common for:

ElderlyElderly FemalesFemales Those who are depressed.Those who are depressed.

Causes:Causes: StressStress Environmental noiseEnvironmental noise Extreme temperaturesExtreme temperatures Change in the surrounding environmentChange in the surrounding environment Sleep-wake schedule problems, e.g., shift work, jet Sleep-wake schedule problems, e.g., shift work, jet

lag.lag. Side effects of medication.Side effects of medication.

InsomniaInsomnia Contributing factors:Contributing factors:

Expecting to have difficulty sleeping.Expecting to have difficulty sleeping. Large amounts of caffeine.Large amounts of caffeine. Drinking alcohol before bedtime.Drinking alcohol before bedtime. Smoking cigarettes before bedtime.Smoking cigarettes before bedtime. Excessive napping in the afternoon or Excessive napping in the afternoon or

evening.evening. Irregular, or continually changing sleep-wake Irregular, or continually changing sleep-wake

schedules.schedules.

Less Common Sleep DisordersLess Common Sleep Disorders NarcolepsyNarcolepsy

Sleep disorder characterized by sudden bouts of Sleep disorder characterized by sudden bouts of irrepressible sleep.irrepressible sleep.

Individual may fall to ground in sound sleep.Individual may fall to ground in sound sleep. Can be dangerous if not controlled.Can be dangerous if not controlled.

Regular hours and sufficient sleep.Regular hours and sufficient sleep. DrugsDrugs

CataplexyCataplexy Individual experiences sudden muscle paralysis as in Individual experiences sudden muscle paralysis as in

REM sleep while they are awake.REM sleep while they are awake. Will collapse.Will collapse.

Sleep WalkingSleep Walking More common in More common in

children.children. Usually outgrown by Usually outgrown by

the age of 15.the age of 15. Occurs during Occurs during

deepest sleep deepest sleep rather than REM rather than REM sleep.sleep.

Night TerrorsNight Terrors

Night TerrorsNight Terrors

Also occurs during deepest, Stage 4 Also occurs during deepest, Stage 4 sleep.sleep.

Most common in children between 4 – 7 Most common in children between 4 – 7 years of age.years of age.

Child wakes crying as if in terror but Child wakes crying as if in terror but seems as if not really awake. No seems as if not really awake. No response to visual stimuli or questions.response to visual stimuli or questions.

May, or may not report a scary dream May, or may not report a scary dream when fully awake.when fully awake.

What is Sleep For?What is Sleep For?

It seems to be restorative:It seems to be restorative: Restores glycogen stores and stengthens the immune Restores glycogen stores and stengthens the immune

system.system. Bodily repair—extremely active people sleep more.Bodily repair—extremely active people sleep more.

Bodily rhythms may have evolved to ensure Bodily rhythms may have evolved to ensure quiet periods during time when most predators quiet periods during time when most predators for the species are about. for the species are about.

Consolidation of learning:Consolidation of learning: Lack of sleep interferes with memory storage.Lack of sleep interferes with memory storage.