circadiánního

Circadiánní refers to biological processes that oscillate with a roughly 24-hour cycle. These cycles, known as circadian rhythms, are endogenous and are influenced by external cues, primarily light. The term "circadian" comes from the Latin words "circa" meaning "around" and "dies" meaning "day." These rhythms are fundamental to the functioning of most living organisms, regulating sleep-wake patterns, hormone release, body temperature, and other physiological and behavioral functions.

The master clock that orchestrates these rhythms in mammals is located in the suprachiasmatic nucleus (SCN) of the hypothalamus in the brain. The SCN receives light signals directly from the eyes, which helps to synchronize the internal clock with the external day-night cycle. When light exposure is disrupted, such as during shift work or jet lag, circadian rhythms can become desynchronized, leading to various health issues including sleep disorders, metabolic problems, and increased risk of certain diseases. Understanding circadian rhythms is crucial for maintaining health and well-being, and for developing effective treatments for sleep-related disorders and other conditions influenced by these biological cycles.