Brain's Internal Clock

The brain's internal clock, often called the circadian rhythm, is a biological system that regulates your daily sleep-wake cycle and other bodily functions over approximately 24 hours. It is controlled primarily by a small group of cells in the brain called the suprachiasmatic nucleus (SCN), located in the hypothalamus. This clock responds to environmental cues like light and darkness, helping you feel alert during the day and sleepy at night. It also influences hormones, body temperature, and metabolism, ensuring your body functions harmoniously with the day-night cycle.