1 / 16

Sleep

Swetha Rao. Sleep. Why is sleep important?. We sleep for nearly 1/3 of our lives Concentration, Memory, and Coordination Sleep Loss = Alcohol

tybalt
Download Presentation

Sleep

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Swetha Rao Sleep

  2. Why is sleep important? • We sleep for nearly 1/3 of our lives • Concentration, Memory, and Coordination • Sleep Loss = Alcohol • Lack of sleep can increase risk of diabetes, cardiovascular disease and heart attacks, stroke, depression, high blood pressure, obesity, and infections • Sleep Disorders affect up to 70 million people

  3. Slow Wave Sleep • First hour or so brain waves slow down • relaxation of the muscles and the eyes • Heart rate, blood pressure, and body temperature all fall • If awakened, most people recall only fragmented thoughts, not an active dream

  4. REM Sleep • Rapid Eye Movement • Next half hour or so, neocortical EEG waves become similar to waking • Atonia: paralysisof the body’s muscles (only the muscles that allow breathing and control eye movements remain active) • Active dreaming • Heart rate, blood pressure, and body temperature become much more variable • Men often have erections • First REM period usually lasts 10 to 15 minutes.

  5. Stages of Sleep

  6. Insomnia • Initially or partway awakening • Short-acting sedatives and sedating antidepressant drugs suppress deeper stages of slow wave sleep

  7. Obstructive Sleep Apnea • Deeper sleep = Airway muscles collapse and close airway • Can’t enter deeper stages of slow wave sleep • High blood pressure, increased risk of heart attack, increased risk of automobile accidents, • Treatments to reduce airway collapse: lose weight, avoid alcohol and sedating drugs, avoid sleeping on back • Devices that induce continuous positive airway pressure

  8. Muscles fail to become paralyzed • Periodic Limb Movements • Intermittent jerks of legs and arms as entering slow wave sleep • REM Behavioral Disorder • Muscles fail to become paralyzed • Act out dreams • Common in Parkinson’s patients • Treated with: benzodiazepine (clonazepam)

  9. Narcolepsy • Switching mechanisms don’t work properly • Loss of nerve cells in the lateral hypothalamus which contains the neurotransmitter orexin • Narcoleptic Dog: http://www.youtube.com/watch?v=X0h2nleWTwI

  10. Sudden Sleep Attacks during the day • Hypnagogic Hallucination: Enter REM sleep and dreaming state while still partially awake • Cataplexy: Attacks of paralysis triggered by emotional experience

  11. Sleep Regulation: AWAKE • Acetylcholine and Monoamines (norepinephrine, serotonin, dopamine, and histamine)

  12. REM sleep: • Cholinergic nerve cells send signals to activate the thalamus • EEG similar to wakefulness • Monoamine pathway is quiet • Perceived as a dream

  13. Waking Up • Two groups of nerve cells in hypothalamus • Ventrolateralpreoptic nucleus: • GABA and galanin • When they fire, they turn off arousal system and cause sleep • Damage = irreversible insomnia • Neurotransmitter orexin: • Excitatory signal to monoamine neurons • Orexin levels in patients with narcolepsy are abnormally low

  14. Need for Sleep: Homeostasis • Body’s need to seek a natural equilibrium • Adenosine (chemical) • increases in the brain during prolonged wakefulness • levels modulate homeostasis • Caffeine acts as an adenosine blocker

  15. Circadian Timing System • Suprachiasmatic nucleus: group of nerve cells in hypothalamus that acts as a master clock • Cells express clock proteins which go through biochemical cycle of 24 hrs • Receives input from retina so can be reset by light

  16. Suprachiasmatic nucleus • Subparaventricular nucleus • Dorsomedial nucleus of hypothalamas • Ventrolateralproptic nucleus (orexin) • Regulate sleep and arousal

More Related