Why Do We Need Sleep?

What happens if we dont get enough sleep? Sleep is an essential period of rest and rejuvenation that plays is an important part of normal body function. Sleep helps to organize memories, improve concentration, and effects emotions, social interaction, and decision making. It also benefits our immune system, nervous system, and development. Without proper sleep, the immune system becomes weak and your body is more suceptable to disease. Sleep is also the period where you undergo neuron repair. Many hormones, substances produced to trigger or regulate particular body functions, are timed to release during sleep or right before sleep. Growth hormones, for example, are released during sleep, vital to growing children but also for restorative processes like muscle repair.Sleep deprevation can be short term, which occurs regularly in college students staying up late to study, or ir can be chronic which is continuous sleep deprevation. Sleep deprivation adds up to what is called a sleep debt, which can range from one night’s very poor sleep to the accumulation of many days of not enough sleep. It can take days to repair from chronic sleep deprevation. Your sleep is regulated by an internal body clock, sensitive to light, time of day and other cues for sleep and awakening. When you fall asleep, your sleep goes in cycles throughout the night, moving back and forth between deep restorative sleep and more alert stages and dreaming. There are four stages, the first of which is drowsiness where you are relaxed but easily awakened, the second is light sleep wehre eye movement stops, body temperature decreases, and heart rate slows. The third is deep sleep whereblood flow is distributed more to the muscles to repair them and your immune system. If awakened during this stage, often feel groggy and disoriented. At about 70 to 90 minutes into your sleep cycle, you enter REM sleep. You usually have three to five REM episodes per night. This stage is associated with processing emotions, retaining memories and relieving stress. Breathing is rapid, irregular and shallow, the heart rate increases, and blood pressure rises.

http://www.helpguide.org/life/sleeping.htm