1. References: https://www.sleepassociation.org/patients-general-public/what-is-sleep/ https://sleepfoundation.org/sleep-disorders-problems/abnormal-sleep- behaviors/sleepwalking

2. Stages Usually sleepers pass through five stages: 1, 2, 3, 4 and REM (rapid eye movement) sleep. These stages progress cyclically from 1 through REM then begin again with stage 1. A complete sleep cycle takes an average of 90 to 110 minutes. As the night progresses, REM sleep periods increase in length while deep sleep decreases. By morning, people spend nearly all their sleep time in stages 1, 2, and REM

3. StageCharacteristics 1light sleep, can be awakened easily, our eyes move very slowly and muscle activity slows. People awakened from stage 1 sleep often remember fragmented visual images. Many also experience sudden muscle contractions called hypnic myoclonia, often preceded by a sensation of starting to fall. These sudden movements are similar to the “jump” we make when startled. 2eye movements stop, brain waves become slower, with occasional bursts of rapid waves called sleep spindles. ¾extremely slow brain waves, very difficult to wake someone during deep sleep, no eye movement or muscle activity. Upon awakening people do not adjust immediately and often feel groggy and disoriented for several minutes after they wake up. Some children experience bedwetting, night terrors, or sleepwalking during deep sleep REMRapid & shallow breathing, eyes jerk rapidly in various directions, limb muscles become temporarily paralyzed, heart rate increases, blood pressure rises, and males develop penile erections

4. How does our brain know it is time to sleep? neurotransmitters control whether we are asleep or awake by acting on different groups of nerve cells in the brain. Neurons in the brainstem produce neurotransmitters (serotonin and norepinephrine) that keep some parts of the brain active while we are awake. Other neurons at the base of the brain begin signaling when we fall asleep. These neurons appear to “switch off” the signals that keep us awake. Tryptophan and melatonin have a similar effect on our brain

5. Circadian Rhythms Circadian rhythms are regular changes in mental and physical characteristics that occur in the course of a day (circadian is Latin for “around a day”) controlled by the body’s biological “clock.” This clock, called the suprachiasmatic nucleus or SCN, is actually a pair of pinhead-sized brain structures that together contain about 20,000 neurons. The SCN rests in a part of the brain called the hypothalamus, just above the point where the optic nerves cross. Light that reaches photoreceptors in the retina creates signals that travel along the optic nerve to the SCN.

7. Then what… Signals from the SCN travel to several brain regions, including the pineal gland, This responds to light-induced signals by switching off production of the hormone melatonin.melatonin The body’s level of melatonin normally increases after darkness falls, making people feel drowsy. The SCN also governs functions that are synchronized with the sleep/wake cycle including body temperature, hormone secretion, urine production, and changes in blood pressure.

8. Do you get enough sleep? How do we know? What are some warning signs that you do? Do not? What are some sleep disorders you have heard of?

9. Insomnia…not keeping yourself awake Almost everyone occasionally suffers from short-term insomnia. Reasons: stress, jet lag, diet, or many other factors. Insomnia almost always affects job performance and well-being the next day. About 60 million Americans a year have insomnia frequently or for extended periods of time Insomnia tends to increase with age and affects about 40 percent of women and 30 percent of men. It is often the major disabling symptom of an underlying medical disorder. Mild insomnia often can be prevented or cured by practicing good sleep habits For more serious cases of insomnia, researchers are experimenting with light therapy and other ways to alter circadian cycles.

10. Sleep Apnea a disorder of interrupted breathing during sleep It usually occurs in association with fat buildup or loss of muscle tone with aging. Because of this the windpipe to collapse during breathing when muscles relax during sleep. is usually associated with loudsnoring snoring Sleep apnea also can occur if the neurons that control breathing malfunction during sleep. This blocks the air flow for 10 seconds to a minute while the sleeping person struggles to breathe This cycle may be repeated hundreds of times a night

11. Restless Leg Syndrome a familial disorder causing unpleasant crawling, prickling, or tingling sensations in the legs and feet and an urge to move them for relief, common especially among older people. This disorder, which affects as many as 12 million Americans, leads to constant leg movement during the day and insomnia at night.

12. Narcolepsy frequent “sleep attacks” at various times of the day, even if they have had a normal amount of night-time sleep. These attacks last from several seconds to more than 30 minutes. People with narcolepsy also may experience cataplexy (loss of muscle control during emotional situations), hallucinations, temporary paralysis when they awaken, and disrupted night-time sleep. These symptoms seem to be features of REM sleep that appear during waking, which suggests that narcolepsy is a disorder of sleep regulation. The symptoms of narcolepsy typically appear during adolescence The disorder (or at least a predisposition to it) is usually hereditary occasionally is linked to brain damage from a head injury or neurological disease.

13. Sleep Walking formally known as somnambulism is a behavior disorder that originates during deep sleep and results in: walking or performing other complex behaviors while asleep. It is much more common in children than adults is more likely to occur if a person is sleep deprived. Because a sleepwalker typically remains in deep sleep throughout the episode person may be difficult to awaken and will probably not remember the sleepwalking incident.

14. Sleepwalking is most often initiated during deep sleep but may occur in the lighter sleep stages or NREM, usually within a few hours of falling asleep, and the sleepwalker may be partially aroused during the episode. In addition to walking during deep sleep, other symptoms of sleepwalking include: Sleeptalking Little or no memory of the event Difficulty arousing the sleepwalker during an episode Inappropriate behavior such as urinating in closets (more common in children) Screaming (when sleepwalking occurs in conjunction with sleep terrors)

15. Sleep Studies Sleep studies are tests that measure how well you sleep and how your body responds to sleep problems. These tests can help your doctor find out whether you have a sleep disorder and how severe it is. Sleep studies are important because untreated sleep disorders can raise your risk for heart disease, high blood pressure, stroke, and other medical conditions.heart diseasehigh blood pressurestroke Reference: http://www.nhlbi.nih.gov/health/health-topics/topics/slpst/during

17. Before the lab… 5/9 & 5/10 Make sure you have: Title Problem Background Information Pre-lab questions Hypothesis