Before understanding what sleep is for, you must first understand how sleep works. To pace the day, the human body follows the biological clock.
This clock located in the brain regulates several functions such as appetite, mood, body temperature but also sleep: this is what interests us. It is based on the circadian rhythm: a cycle of about 24 hours, which corresponds to a day or so… Overall this clock follows the alternation of day and night but as it does not last exactly 24 hours it needs to be “reset”.
To help him readjust one factor is very important: light. At the back of our eyes, at the level of the retina, we all have sensors that are sensitive to light, even if our eyelids are closed. These sensors are connected via a nervous system to the biological clock and when the sun rises or sets, they transmit the message to it, which allows the biological clock to reset itself on a 24-hour cycle. But the light is not the only factor that gives the signal to go to bed. The brain also produces a hormone: melatonin, nicknamed the sleep hormone.
Well now that we’ve explained this to you, you’re probably wondering what happens when we sleep and why? To understand all this, watch the video at the top of the article.