Losing sleep produces significant consequences to the overall health of a body. There have been numerous tragedies in history linked to errors by tired, sleep-deprived humans. Two major events caused by fatigue were the Exxon Valdez Oil Spill and the NASA Challenger shuttle explosion. The horrendous outcomes of these events are why humans need a better understanding of how sleep affects their quality of life. (NSF) When sleep is lost, there may be detrimental effects to your health and the well-being of others.
Sleep is “the resting state in which the body is not active and the mind is unconscious”. (English) A person who sleeps well will awake more refreshed and alert. A good night’s sleep has a major impact on how a person looks, feels, and their ability to function normally on a daily basis. (What) Everyone must sleep because sleep is essential in sustaining normal levels of cognitive speech, memory, and critical thinking. The brain’s development is directly affected by the amount of sleep the body receives. (BBC)
The sleep-cycle is what makes everyone sleep and wake up every night and morning. The basic mechanisms of the sleep-wake cycle consist of approximately 8 hours of nocturnal sleep and 16 hours of being awake. This cycle is controlled by combination internal influences of both sleep homeostasis and circadian rhythms. Homeostasis is “the process by which the body maintains a steady state of internal conditions such as blood pressure, body temperature, and acid-base balance”, and Circadian rhythms “refer to the cyclical changes-like fluctuations in body temperature, hormone levels, and sleep that occurs over a 24 hour-period”. (NSF)
There are two types of sleep. The first type, rapid eye movement (REM) sleep is the active period of sleep marked by powerful brain activity. Breathing becomes more rapid and shallow. The eyes move quickly and in different directions and the body’s muscles become paralyzed temporarily. This stage is when most people will have dreams. (NSF)
The second type of sleep is non-REM sleep (NREM) which is characterized by a reduction in physiological activity. NREM sleep consists of four distinct stages. Stage 1 is when the brain waves and muscles start to slow down and the transition is made from being awake to falling asleep. Stage 2 is when light sleep begins and the heart rate slows while the body temperature decreases. Stages 3 and 4 which are referred to as, the slow wave sleep, is when the body goes into a deep sleep. There is no eye movement, and decreased muscle activity. Blood pressure drops, breathing begins to slow, and the body temperature drops even lower. Some children have experienced bedwetting, night terrors and sleep walking during this stage.
All of these stages have an important role in the overall health of sleep and it is important to find the right balance between them. Finding the balance in these stages is crucial for learning, memory, mood and concentration.
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