Mechanics of Dreaming
you are dreaming, your body undergoes noticeable changes. Your adrenaline
rises, your blood pressure increases, and you heart beats faster. Given this
hyperactivity, it should be no surprise how someone with a weak heart can die in
their sleep. Their heart may not be able to withstand the strain and the
erratic changes that their body is going through.
takes place during REM, which stands for Rapid
Eye Movement. It is thus called,
because your eyes move rapidly back and forth under the
eyelids. REM sleep takes place in the fourth stage of sleep and accounts
for 15-20% of your sleep time. From the point you fall asleep, it takes 30 to 90
minutes before you start dreaming. You cycle through the 4 stages of sleep and
may enter the REM stage 4 to 7 times in one night. During REM, your blood
pressure and heart rate fluctuate and increase. It sounds like your body is
going through a lot, but in fact, it is quite the contrary. During REM, your
bodies are completely immobile and your muscles remain completely relaxed. You
may shift in your bed throughout the night, but when in REM, you are completely
still. This is commonly known as "REM Paralysis".
REM sleep, the mind is as active as it is during waking.
However, chemically it is different. REM is controlled by the excitability level
of the cholinergic neurons. Noradrenaline and seratonin are missing in the brain
when in the dream state. These chemicals allow the brain to carry out task,
solve problems and remember things. This is a reason why you find it so hard to
remember your dreams.