* It restores the body’s energy.
* It gives the body a chance to repair itself and regenerate.* It helps the brain organize and store memories.
* It may recharge the brain. Adenosine signals the brain when it needs sleep. Adenosine triphospate (ATP) releases energy to fuel reactions. With each burst of energy, ATP loses it triphospate molecule, and the adenosine binds to receptors. Rising levels of adenosine signal the brain it needs rest. Although scientists once thought that caffeine induced alertness by blocking sedating mechanisms in the body, they now know that caffeine blocks the the receptors adenosine binds to.
Amount of sleep needed
Everyone’s individual sleep needs vary. In general, most healthy adults are built for 16 hours of wakefulness and need an average of eight hours of sleep a night. However, some individuals are able to function without sleepiness or drowsiness after as little as six hours of sleep. Others can’t perform at their peak unless they’ve slept ten hours. And, contrary to common myth, the need for sleep doesn’t decline with age but the ability to sleep for six to eight hours at one time may be reduced. (Van Dongen & Dinges, Principles & Practice of Sleep Medicine, 2000)
What causes sleep problems?
Psychologists and other scientists who study the causes of sleep disorders have shown that such problems can directly or indirectly be tied to abnormalities in the following systems:
Physiological systems
* Brain and nervous system
* Cardiovascular system
* Metabolic functions
* Immune system
Furthermore, unhealthy conditions, disorders and diseases can also cause sleep problems, including:
* Pathological sleepiness, insomnia and accidents
* Hypertension and elevated cardiovascular risks (MI, stroke)
* Emotional disorders (depression, bipolar disorder)
* Obesity; metabolic syndrome and diabetes
* Alcohol and drug abuse
(Dinges, 2004)
Lack of Sleep and the Consequences
Since sleep is responsible for the body’s restorative functions, the lack of sleep can be deleterious upon an individual’s health. The consequences of sleep deprivation can affect the following areas:
* Reduced performance and lack of concentration cause impaired learning.
* Depression. People who are depressed have shorter lengths of REM sleep. It is also a viscous circle. Depression may cause sleep loss and vice-versa.
* Increased mental illness
* Decreased immune system function
* Increased pain perception
* Decreased ability to metabolize glucose and an increased risk of diabetes.
* May trigger the release of stress hormones and an increased risk of heart attacks and strokes.
* An increased risk of breast and colon cancer. Melatonin fights abnormal cell growth, especially in breast cancer and colon cancer. Since melatonin is released at night, less sleep means less melatonin. Thus, a reduced cancer-fighting ability.
* Increased car accidents and occupational accidents
* Increased inflammation
