Sleep is defined as a state of the body when the body and mind are at rest. During this time the consciousness and bodily functions of the body are suspended partially. Sleep is an important essential and universal biological rhythm. In this essay, we examine the types of sleep, how sleep is measured and the changes in sleep patterns as one age. We will further dwell on sleep theories, sleep deprivation and sleep disorders.
Although there are many sleep measures, an electroencephalograph, EEG, is used as an indicator of sleep pressure in a wake animal. Recorded interactions between the thalamus and neurons are believed to be a transition from sleep and wake. The sleep measurement has a great utility in quantifying disease burdens and measure treatment response as well as determining how fit one is to work or drive.
Types of sleep
There are generally two types of sleeps that alternate when a person is sleeping. They are: slow wave synchronized sleep (NREM) and desynchronized dream sleep (REM). Non-Rapid Eye Movement sleep has four stages: 1, 2, 3, and 4 then goes to Random Eye Movement and again to stage 1. The first stage of sleep occurs as one drifts in and out of sleep but can easily be awakened. The muscle activity slows as the eyes move slowly, some people may experience muscle contractions.
The second stage involves slowing of brain waves unless an occasional burst with stopping of eye movements. Stage three involves extremely slow brain waves which are interspersed with smaller and faster waves. In stage four, the brain rarely produce delta waves experienced in stage three when the person is in deep sleep. It does not involve eye movement nor muscle activity. From stage four, we enter the REM period where the breathing is more rapid, shallow and irregular. The eyes can rapidly jerk, brain waves increase as well as the heartbeat and some people can remember dreams at this time (Cherry K. 2010).
Changes in sleep with age
Sleep patterns change as one ages, this is because as one ages there are some developmental changes that occur which also change sleep patterns. For newborn babies, they sleep an average of 16-18 hours a day and by age one or two, they reduce to about 12-13 hours. Teenagers require about 8-9 hours of sleep while adults need 8 hours of undisturbed sleep. The elderly also need the same time of 8 hours as normal adults (Harvard Medical School).
Researchers have discovered ways to study sleep in objective and systematic ways. Researchers have investigated on the reasons why people sleep and the functions of sleep. The main theories they have come with are: Repair and Restoration Theory of Sleep, Information Consolidation Theory of Sleep and evolutionary theory of sleep.
According to the RRTS, sleep is important to revitalize and restore the physiological processes that keep the mind and body healthy and function properly. Theory is supported by the fact that during REM periods, sleep increases after periods of sleep deprivation and strenuous activity. The ETS suggests that activity and inactivity periods evolved to conserve energy thus people sleep when wakefulness could be most hazardous. Theory is supported by the fact that animals with few predators sleep more than animals with many predators. The ICTS is based on cognitive research and suggests that the reason why people sleep is to processes information that was acquired during the day and allows the brain to prepare for the next day. Theory is supported by sleep deprivation that shows that lack of sleep has a negative impact on the ability to remember information (Cherry K. 2010).
Our bodies need a certain amount of sleep daily to function properly and effectively. If a person lacks sleep over a long period of time, some parts of the brain may stop functioning. Sleep deprivation is defined as a disorder characterized by the body not having sufficient sleep. Sleep deprivation is characterized by snoring or choking while asleep, tiredness during the day as well as experiencing shortness of breath or chest pains. Deprivation of sleep can be divided into lifestyle, health complications, medication side effects and clinical disorders.
Sleep deprivation can result to short-term effects like decreased performance and alertness, memory and cognitive impairment, poor life quality due to poor concentration and even risk of causing accidents when driving. Long-term effects are associated with numerous and serious medical illness including high blood pressure, heart attack, mental impairment, attention disorder and growth retardation in children (Causes of Sleep Deprivation).
A sleep disorder is defined as a medical disorder that is caused by disruption in the normal sleeping pattern of a person. Lack of quality sleep can result to causing accidents, health and mental problems. Some of the common sleep disorders are: Insomnia, snoring, sleep apnea and parasomniasis.
Insomnia is the difficulty of initiating sleep or poor quality sleep perception. It is regarded as the inability to obtain sufficient amount of sleep to rest the body. Insomnia is caused by changes in shift work, excessive noise, stressful situations, anxiety, depression, chronic pain and withdrawal from drugs. Treatment here involves having enough sleep and sleeping when feeling sleepy (emedicinehealth). Snoring involves difficulties in keeping the throat open while asleep. Sleep apnea is a chronic condition in which a person repeatedly stops breathing during sleep caused by obstruction of the upper airway. Parasomniasis is characterized by abnormal sleep behaviors like sleep eating, sleepwalking or sleep terrors (Peters B. 2010).
Enough and regular sleep is important for efficient brain and body functions. Lack of enough sleep and irregular sleep can result to several disorders leading to health deterioration. Our bodies need a certain amount of sleep per day to function normally. Therefore, it is important that we have enough sleep to avoid disorders such as insomnia, snoring, parasomniasis and sleep deprivation.
Causes of Sleep Deprivation. Retrieved from: http://www.sleep-deprivation.com/articles/causes-of-sleep-deprivation/index.php
Cherry K. (2010). Sleep –stages, Theories & problems with sleep. Retrieved from: http://psychology.about.com/od/statesofconsciousness/p/sleep101.htm
Emedicinehealth (2010). Retrieved from: http://www.emedicinehealth.com/insomnia/article_em.htm
Harvard Medical School. Changes in sleep with Age. Retrieved from: http://healthysleep.med.harvard.edu/healthy/science/variations/changes-in-sleep-with-age
Peters B. (2010). Overview of common sleep disorders. Retrieved from: http://sleepdisorders.about.com/od/commonsleepdisorders/a/Sleep_Disorders.htm