phys of sleep Flashcards
- Be able to describe the characteristics of REM and N-REM sleep and sleep disorders associated with each stage.
NREM:
• N1, N2 and N3 (slow wave sleep) phases
• High amplitude, slow brain waves
• Increased arousal threshold compared to awake
• Decreased muscle activity
• Slow rolling eye movements
• Decreased heart rate, respiration and metabolism
• Occurs early in sleep
• Disorders of arousal (walking, terrors, night eating, etc.) usually during N3 slow wave sleep
REM:
• Rapid eye movements
• Appx. 90 mins. in adults
• EEG looks like awake
• Increased arousal threshold compared to NREM
• Muscles paralyzed excepts eyes, middle ear and diaphragm
• Temp regulation suspended
• Brain temp rises
• Engorgement of clitoris and penis
• Irregular heart rate and respirations
• Most recallable dreams
• Entered through NREM
• Occurs late in sleep during early morning hours
- Be able to describe the major neurotransmitters involved in wake, NREM and REM sleep.
Your circadian rhythm (process C) operates independently of both behavior (when and how often you sleep) and light input. Light exposure at the appropriate times is helpful in reinforcing this rhythm if it occurs at the appropriate times. In addition to the circadian rhythm, there are homeostatic processes (process S) that contribute to when you feel sleepy. This is not a specific process, but a bunch of changes that occur in your body the longer you are awake. You accumulate certain neurotransmitters (i.e. adensoine) and diminish others over the course of the day and you need to go to sleep in order to get this all back to normal and not feel tired anymore. So it is pressure from both process C and process S that contribute to your sleepiness, which is ultimately reflected in fluctuations in your core body temperature. You are best able to sleep when your core body temperature is lowest and most alert when your body temperature is greatest. Again, this change in body temperature is subject both to your natural circadian rhythm, light exposure and homeostatic pressure that is based on how long you have been awake.
- Be able to describe the interaction of the circadian (process C) and homeostatic system (process S) and their effect on wake and on sleep.
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