We all have one, a circadian clock, otherwise known as a biological clock. Most all living organisms, even plants and fungi, have a biological clock that influences its physiological and developmental functions. Our biological clocks can periodically, and at appropriate intervals, regulate when our bodies should be awake or asleep during a 24-hour period. . What has been an amazing anomaly is how our circadian clocks can maintain normalcy despite our environmental influences, specifically, changes that vary each season such as light, darkness, and temperature.
The circadian clock is regulated by cells in the hypothalamus, located in the Suprachiasmatic Nucleus (SCN) of the brain, and it responds to light and dark signals. For instance, when our eyes see daylight, the optic nerve sends a signal to the SCN, which in turn communicates with our biological clock that it is time to be awake. When our brains sense it is time to be awake, signals are sent by the SCN that raise our body temperature. When our body senses it is time to go to sleep, the SCN signals other parts of the brain that uses body temperature, hormones, and other functions that make you feel sleepy.
This self-sustaining biological clock is a key component when it comes to our sleep cycle. By sending appropriate signals to the brain, our body can always know when we should sleep or be awake.
Our circadian clock can affect us differently at various stages in life. For instance, teenagers often have a difficult time falling asleep early. Melatonin levels in their blood do not elevate until later at night. Circadian clocks are also interrupted when you experience jet lag, which conflicts with your natural pattern of sleep. Even if you sleep irregular hours all of the time, you are disrupting your circadian clock. Our bodies require restful sleep to restore its circadian rhythm. Remember to allow your body the rest it needs, considering both quantity and quality of sleep, which are vital to your circadian clock.
Eckardt, N. A. (2006). A Wheel within a Wheel: Temperature Compensation of the Circadian Clock. The Plant Cell, 18(5), 1105–1108. https://doi.org/10.1105/tpc.106.043356