We spend around one third of our lives asleep, still none of us have any idea why do we sleep. Even the question has puzzled scientists for centuries and the answer is; we are not perfectly sure. Some say we have to sleep to maintain normal rhythm of life while other say, sleep plays an important role in brain development. So, it’s confusion everywhere. In this article I have tried a little bit to shed some light on the sleep cycles and brain activities at that time.
Our internal body clock which alarms us on when to sleep and when to wake up is governed by circadian rhythm. Circadian element releases a hormone called melatonin. Presence of melatonin and gradual decrees in body temperature causes sleepiness in our body. An eight hours sleep can be divided in to two categories REM SLEEP and NON REM SLEEP. A normal adult spend about 80% of their sleep time in NON REM SLEEP and rest 20% in REM SLEEP.
Four Stages of NON REM SLEEP
Stage 1 – It is a primary stage of half awake and half asleep. In this stage individuals can easily be awakened.
Stage 2 – At this stage our heart rate and breathing pattern starts to slow down. Brain waves become slower and then slowly eye moment become less functional.
Stage 3 – now the breathing rate are at their lower levels. At this stage brain produces waves with high amplitude and low frequency.
Stage 4 – This is a stage of limited muscle activity and rhythmic breathing. After the stage 4 a person enters to REM SLEEP. The NON REM SLEEP cycle repeats itself again and again till the end of the sleep without retouching stage 1.
Rapid Eye Moment (REM SLEEP)
The first REM period begins after 70 to 90 minutes of our first sleep phase. It is also known as the “Paradoxical Sleep” because at this time brain activities are similar to the awakened state. Typically, a person has around four to five REM sleep around a night. Breathing rate and blood pressure rises at this time, visual intense dreaming also occurs at REM sleep. But if you think nightmare also comes at REM sleep you are wrong! They are different things and occur during NERM. After each REM sleep the sleep cycle begins aging with and with each succeeding cycle NERM gets shorter and REM grows, giving us around 40 minutes dreaming time just before waking.
Dream And Its Functionality
Dreaming has fascinated mankind since their origin. With its vivid, complex and emotional nature, dreaming has inspired various religious moments, scientific theories and artistic representations. During REM sleep the highly active brain generates certain neurons at random. When brain tries to make sense of this and synthesize random impulse, we experience dreams.
What Is An Ideal Amount Of Sleep?
Like all biological functions sleep length varies form person to person. Studies have shown that quality and quantity of sleep matters a lot when it comes to learning and memorizing things. The amount of sleep requires to a person depends upon their age and the physical activity they perform in a day. A new born generally require about 16 hours, while for a teenagers it is more than enough to take a good 9 hours sleep. For most adults, 7 or 8 hours appears like an ideal sleep, although some may need 10 hours or as even as few as 5 hours. The exact amount of sleep hours are that which keeps you fresh and energetic next morning.
