Definition:

Circadian rhythms are natural, biological processes that occur in a 24-hour cycle. These rhythms regulate various physiological and behavioral processes in living organisms.

Key Features:

• Endogenous: Circadian rhythms are driven by internal, biological clocks that persist even in the absence of external cues.
• Light Sensitivity: Light is a primary cue for synchronizing circadian rhythms and adjusting them to the external environment.
• Periodicity: The cycle of circadian rhythms repeats approximately every 24 hours, although some variations exist among different organisms.
• Influences: Circadian rhythms influence a wide range of functions, including sleep-wake cycles, hormone secretion, body temperature, metabolism, and cognitive performance.

Regulation:

The suprachiasmatic nucleus (SCN) in the brain’s hypothalamus is the central pacemaker that coordinates and regulates circadian rhythms. The SCN receives light input from the retina and synchronizes the internal clocks of the body.

Disruption:

Disruption of circadian rhythms, such as through jet lag, shift work, or sleep disorders, can lead to various health issues, such as sleep disturbances, mood disorders, impaired cognitive function, and metabolic disorders.