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Dr.Griffin
English 12
1 May 2014
Why do we sleep?
It’s weird how sometimes out of nowhere we all get tired and sleepy. We sometimes wish
that at certain times we don’t get tired because we need to be wide awake. You might ask
yourself why we sleep. Or even why do we get tired?
Research have found that our bodies can regulate sleep in the same way that they regulate
eating, drinking, and breathing. Sleep is necessary in order to be able to do anything you want
and you’re energetic. Our mind and body feel relax and great when we sleep, we are happier and
we can be alert of anything. As if you were to be sleepy that would be the only thing you would
think about. You wouldn’t care about anything only your eyes closing and laying down in y our
bed even for ten minutes. Eating and sleeping are controlled by powerful internal drives. Without
food you an uncomfortable feeling of hunger. Animals that have been studied, from the fruit fly
and the frog, also shows some kind of sleep-like behavior. David Prober, assistant professor of
biology stated “We spend so much of our time sleeping that it must be doing something
important,” there are no evidence about why we sleep, but there are four main theories on why
we get tired. The first theory is that sleeping allows the body to repair cells damaged by
metabolic byproducts called free radicals. Scientists found that the appearance of genes involved
in fixing cells gets kicked up a notch during sleep. The test were don on small animals so the
metabolic rates can be higher. An example is some mice sleep about twenty hours a day, while
giraffes and elephants only need two- to three-hour power naps.
Another theory is that sleep helps refill fuel which is burned when you’re awake. An
expected fuel is ATP. When ATP is low the adenosine is high, which sends a message to the
body that it’s time to go to sleep. Sleep can also be a time for your brain to do a little
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housekeeping. When you’re learning and engaging information through the day, you’re always
generating new synapses.
When we sleep we go through five stages. 1, 2, 3, 4, and rapid eye movement. In stage
one (light sleep) we float in and out of sleep and we can be woken up easily. In stage two our eye
movement’s stop and the brain and become slower, with rare burst of rapid waves that’s called
sleep spindles. By stage three, very slow brain waves called delta waves begin to show up and
spreads with smaller and faster waves. On stage four is when you are on deep sleep because
you’re on stages three and four. The brain makes delta waves almost completely. Stage five is
the REM. The rem is when breath more rapid, irregular, and shallow. Our eyes twitch fast in
many directions, and our limb muscles become temporarily paralyzed. Your heart rate increases
and your blood pressure rises. When people awake during REM sleep it is describe as bizarre
and illogical tales dreams.
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Work cited
http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/why-do-we-sleep
http://phys.org/news/2011-02-why-do-we-sleep.html
http://www.ninds.nih.gov/disorders/brain_basics/understanding_sleep.htm