Although you don’t hear it tick, your body has its own clock. We all experience different levels of sleepiness and alertness throughout the day. Staying up late is not an easy task for some people. Have you ever wondered what causes these patterns?
Circadian rhythms are physical, mental, and behavioral changes that follow a roughly 24-hour cycle. It regulates the timing of processes like eating, sleeping, and temperature.
Our biological clocks drive our circadian rhythms. About 20,000 nerve cells make up our “master clock,” a part of our brain called the suprachiasmatic nucleus. This structure, which sits inside an area called the hypothalamus, controls your circadian rhythms.
Can you trick your biological clock to function a certain way? Are you more intelligent than you think you are?
The most significant signal is the light. Your body is wired to sleep when it’s dark and stay awake when it’s bright outside. Nerves directly link your eyes and your body’s master clock. When daylight fades, your eyes signal your brain to make more melatonin, a hormone that makes you feel sleepy. And when the sun rises again, the signals tell the brain to turn down the melatonin.
Biological clocks regulate the timing of periods of sleepiness and wakefulness throughout the day. The circadian rhythm dips and rises at different times of the day. Adults normally experience the strongest sleep drive between 2:00-4:00 am and in the afternoon between 1:00-3:00 pm, although there is some variation depending on whether you are a “morning person” or an “evening person.” The sleepiness we experience during these circadian dips will be less intense if we have had sufficient sleep, and more intense when we are sleep deprived. The circadian rhythm also causes us to feel more alert at certain points of the day, even if we have been awake for hours.
The circadian rhythms generated by our internal biological clocks vary from individual to individual; most clocks run slightly longer than 24 hours, while some run slightly shorter. This is why some people are early birds and some night owls.