What causes us to wake up from our sleep?

Update:

Ok, we're unconcious ... what is the thing that in your subconcious tells you that you're rested??? How is that determined?

Update 2:

I don't get what wikipedia is trying to tell me ... help ... http://en.wikipedia.org/wiki/Sleep#Theories_regard...

15 Answers

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  • 1 decade ago
    Favorite Answer

    we sleep in 90 minute cycles, from level one sleep to rem. rem sleep will last only 5 or ten minutes at a time, the cause of waking is usually a recognizing of sound, an uncomfortable feeling (springy mattresses are the worse) however in the mornings our brains will start to release a hormone in response to surrounding light which triggers the brain to stop the sleep cycles.

  • Anonymous
    1 decade ago

    Normal sleep is divided into non–rapid eye movement (NREM) and rapid eye movement (REM) sleep. The stages of sleep are stage I (light sleep), stage II, stages III and IV (deep or delta-wave sleep), and REM sleep; NREM sleep comprises stages I-IV. Sleep is an active process that cycles at an ultradian rhythm of about 90 minutes.

    Waking usually transitions into NREM sleep. REM follows NREM sleep and occurs 4-5 times during a normal 8- to 9-hour sleep period. The first REM period of the night may be less than 10 minutes in duration, while the last may exceed 60 minutes.

    For the purpose of analysis, overnight sleep has been divided into 3 equal time periods: sleep in the first third of the night, which comprises the highest percentage of NREM; sleep in the middle third of the night; and sleep in the last third of the night, the majority of which is REM. Awakening after a full night's sleep is usually from REM sleep.

    Circadian sleep rhythm is 1 of the several intrinsic body rhythms modulated by the hypothalamus. The suprachiasmatic nucleus sets the body clock to approximately 25 hours, with both light exposure and schedule clues entraining to the 24-hour cycle. The retinohypothalamic tract allows light cues to directly influence the suprachiasmatic nucleus. Light is called a "zeitgeber," a German word meaning "time-giver," because it sets the suprachiasmatic clock. A practical purpose has been proposed for the circadian rhythm, using the analogy of the brain being somewhat like a battery charging during sleep and discharging during the wake period.

    The nadir of the rhythm is in the early morning. The downswing in circadian rhythm prior to the nadir is thought to assist the brain to remain asleep overnight for full restoration by preventing premature awakening. The morning upswing then facilitates awakening and through the day acts as a counterbalance to the progressive discharge of wake neuronal activity. After the circadian apex in the early evening, the downswing aids sleep initiation. This model explains the relatively steady cognitive function throughout wakefulness.

  • Elwood
    Lv 4
    1 decade ago

    Stimuli breaks through the unconscious and tells us to wake up. Or the brain is sufficiently rested and is ready to go back to work.

  • someone putting tobascco sauce on your tounge while your sleep! Man, you start dreaming your caught in a volcanoe, then you wake up screaming and running around like a crazy person.

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  • Anonymous
    1 decade ago

    For me, the thing that tells me I'm rested and it's time to get up, is my alarm clock.

    Source(s): My Incredibly Superior Intellect
  • 1 decade ago

    Things that go bump in the night.

  • 1 decade ago

    A nightmare.

  • 1 decade ago

    my cat determines if I am rested.

    When she thinks it's time for me to get up, she makes sure I know about it.

  • 1 decade ago

    Enough sleep.

  • Anonymous
    1 decade ago

    the damn car alarm that randomly goes off down my block

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