cirkadiální

Cirkadiální refers to biological rhythms that occur approximately every 24 hours. These rhythms are endogenous, meaning they are generated by internal biological mechanisms, but they are also entrained by external cues, most notably the light-dark cycle. The most well-known example of a cirkadiální rhythm is the sleep-wake cycle, which governs when we feel sleepy and when we feel alert.

These internal biological clocks are found in most living organisms, from bacteria and fungi to plants and animals, including humans. In mammals, the master clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus in the brain. The SCN receives light information from the eyes and synchronizes various bodily functions with the external environment.

Cirkadiální rhythms influence a wide range of physiological processes beyond sleep, including hormone release, body temperature, metabolism, and cell regeneration. Disruptions to these rhythms, such as those caused by shift work, jet lag, or irregular sleep patterns, can have significant negative impacts on health. These can include increased risk of sleep disorders, metabolic syndrome, cardiovascular disease, and even certain types of cancer. Maintaining a regular sleep schedule and exposure to natural light are crucial for keeping these internal clocks aligned.