Hormones 2016

Sleep
• Establish a pre-sleep ritual,
• Avoid stimulation or bright lights right before bed,
• Exercise regularly (womeninbalance.org, 2016a).
Importance of sleep
Animal studies have shown that sleep is necessary for survival. The normal
life span of rats is 2 to 3 years. However, rats deprived of sleep live for
only about 3 weeks. They also develop abnormally low body temperatures
and sores on their tails and paws. The sores probably develop because of
impairment of the rats’ immune systems.
In humans, it has been demonstrated that the metabolic activity of the
brain decreases significantly after 24 hours of sustained wakefulness. Sleep
deprivation results in a decrease in body temperature, a decrease in immune
system function as measured by white blood cell count (the soldiers of the
body), and a decrease in the release of growth hormone. Sleep deprivation
can also cause increased heart rate variability.
For our nervous systems to work properly, sleep is needed. Sleep
deprivation makes a person drowsy and unable to concentrate the next
day. It also leads to impairment of memory and physical performance and
reduced ability to carry out mathematical calculations. If sleep deprivation
continues, hallucinations and mood swings may develop.
Release of growth hormone in children and young adults takes place during
deep sleep. Most cells of the body show increased production and reduced
breakdown of proteins during deep sleep. Sleep helps humans maintain
optimal emotional and social functioning while we are awake by giving
rest during sleep to the parts of the brain that control emotions and social
interactions.
Stages of Sleep
As mentioned earlier, sleep is a dynamic process. There are two distinct
states that alternate in cycles and reflect differing levels of neuronal activity.
Each state is characterized by a different type of brain wave (electrical
activity that is recorded with the help of electrodes placed on the skull)
activity. Sleep consists of nonrapid eye movement (NREM) and rapid eye
movement (REM) sleep. NREM is further subdivided into the following
four stages:
• Stage I (light sleep)
• Stage II
• Stage III & IV (deep sleep)
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Version 2016.3576– – Document LATEXed – 1st May 2016
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