suprachiasmatické

The suprachiasmatic nucleus (SCN) is a tiny structure located in the hypothalamus of the brain, just above the optic chiasm, where the optic nerves cross. It is considered the master biological clock of the body. The SCN receives direct input from the retina of the eyes, allowing it to sense light and darkness. This light information is crucial for synchronizing the body's internal rhythms with the external day-night cycle.

The primary function of the SCN is to regulate circadian rhythms, which are the approximately 24-hour cycles of biological processes such as sleep-wake patterns, hormone release, body temperature, and metabolism. Neurons within the SCN generate their own rhythmic electrical activity, which is then communicated to other parts of the brain and body. This internal timing mechanism ensures that various physiological functions occur at the appropriate times throughout the day and night.

Disruptions to the SCN's function can lead to a variety of sleep disorders and other health problems. For instance, jet lag occurs when the SCN's internal clock is out of sync with the new time zone. Similarly, shift work can desynchronize circadian rhythms, potentially increasing the risk of metabolic disorders, cardiovascular disease, and certain cancers. Research into the SCN continues to shed light on the complex interplay between our internal biology and the environment.