Vuorokausisyklit

Vuorokausisyklit, also known as circadian rhythms, are natural, internal processes that regulate the sleep-wake cycle and repeat roughly every 24 hours. These biological rhythms are found in most living things, including animals, plants, and fungi. In humans, the primary driver of the circadian rhythm is the suprachiasmatic nucleus (SCN), a small region in the hypothalamus of the brain. The SCN receives light cues from the eyes, which helps to synchronize the internal clock with the external environment.

The absence of light, such as during the night, signals the SCN to produce melatonin, a hormone that promotes sleep. Conversely, exposure to light in the morning suppresses melatonin production, leading to wakefulness. Disruptions to these cycles, often caused by shift work, jet lag, or irregular sleep schedules, can have negative effects on health, including impaired cognitive function, mood disturbances, and increased risk of chronic diseases. Maintaining a regular sleep-wake pattern is crucial for optimal health and well-being, as it ensures the body's physiological processes, such as hormone release, body temperature, and metabolism, are aligned with the daily cycle. Environmental factors, particularly light exposure, play a significant role in regulating these rhythms.