The Science Behind Sleep
Written by Aanya Deshpande
At the end of a long day at school and work, I only want to sleep or take a power nap. Sleep is one of my ways to give my brain a break from stress. Many people around the world feel the same way about sleep, and how positively it can affect them. However, there is a reason why people sleep after a long day.
How the Brain Knows When to Sleep
Nerve cells release neurotransmitters to send messages throughout the brain. The neurotransmitters contain hormones such as serotonin, norephedrine, and histamine. Similarly, other nerve cells stop sending messages to the brain to stay awake. Adenosine is the primary chemical involved in this process. Adenosine slowly builds in the bloodstream while one is awake, and then it dissipates when the brain sleeps.
Sleep and Wake Cycles
Two functions regulate sleeping and waking periods. These are sleep/wake homeostasis and the circadian biological clock.
Sleep/wake homeostasis is the longer the body is awake and conscious, the greater the need to sleep is. However, the circadian biological clock causes greater and less drowsiness throughout certain times of the day. For example, adults feel tired between 2 AM to 4 AM and 1 PM to 3 PM.
Both of these processes are controlled by a region in the brain known as SCN (suprachiasmatic nucleus). The SCN is sensitive to certain levels of light, mainly super high or super low lights. For example, the optic nerve in your eyes senses the morning light. Then the SCN triggers the release of primarily cortisol to help the brain awaken. However, when it gets
dark, the SCN sends neurotransmitters to the pineal gland. This gland triggers the release of melatonin. Melatonin is a chemical that makes the brain tired.
Overall, sleep is very important to the human body. Sleep is needed to keep the body energized. Neurotransmitters get released throughout the brain to trigger the need for sleep. Adenosine is the main chemical involved in this process. There are also certain sleep and wake cycles known as sleep/wake homeostasis and the circadian biological clock. These processes control the body’s internal clock, and when to sleep. Everyone is different when it comes to sleep, and everyone needs sleep at different times. Just remember that it is completely fine to take a short nap directly after school, or at any time you feel tired.
SOURCES:
https://www.hopkinsmedicine.org/health/conditions-and-diseases/sleepwake-cycles
Written by Aanya Deshpande from MEDILOQUY