What Are Biological Clocks and How They Unnoticeably Control the Body

The article explains what biological clocks and circadian rhythms are, how they regulate sleep, appetite, temperature, blood pressure, and hormones. It describes the role of the hypothalamus, the effect of light on melatonin production, and the consequences of rhythm disruptions due to night work, jet lag, and irregular sleep. Recommendations for maintaining a regular schedule are given. The 2017 Nobel Prize for the discovery of molecular mechanisms of circadian rhythms is mentioned.

The article discusses biological clocks—the internal mechanism that controls human circadian rhythms. The main center is in the hypothalamus, which responds to light: during the day it promotes wakefulness, at night it stimulates melatonin production for sleep. Many organs and cells have their own rhythms, and the central system coordinates them. Circadian rhythms affect body temperature, blood pressure, hormones, digestion, and immunity. Disruptions occur with night work, time zone travel, and irregular sleep; bright light in the evening also shifts rhythms. To maintain a stable rhythm, regular sleep schedule, morning light, and reduced bright light in the evening are recommended. In 2017, the Nobel Prize was awarded for the discovery of molecular mechanisms controlling circadian rhythms.