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Explanations on a very simple phenon

  1. Jun 16, 2005 #1
    How can you explain biologically why we are sleepy ? I find even people who have normal sleep order also feel sleepy often....
  2. jcsd
  3. Jun 16, 2005 #2
    sleep is an interesting thing...there is an organ deep in the brain called the pineal gland, the ancients called it the "3rd eye", and in lower vertebrate it actually is a functioning light-receptor (by passing light through an opening). Our no longer receives light directly, and has migrated deep in the brain near the hypothalmus. In humans it is linked in the optic chiasm and receives signals from the eyes. It has been determined that the circadian cycle of sleep is determined by this gland and it's production of serotonin.

    It is also believed that LSD acts directly on cells of this organ. Descartes called it the "seat of consciousness".
  4. Jun 17, 2005 #3
  5. Jun 17, 2005 #4
    the pineal makes serotonin, then serotonin gets made into melatonin which then gets released from the pineal gland. the pineal can make an overproduction of serotonin, which does not get converted into melatonin.

    LSD is a serotonin antagonist.
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