Kuna kitu kinaitwa "biological clock" kinacontrol patterns za usingizi.
The system that regulates an organism’s innate sense of time and controls circadian rhythms is called a
biological clock. It’s composed of
proteins encoded by thousands of
genes that switch on and off in a specific order. A master clock coordinates all the biological clocks in an organism.
In
vertebrate animals, including humans, the master clock exists in the brain. The human master clock is a large group of
nerve cells that form a structure called the suprachiasmatic nucleus (SCN). Among other functions, the SCN controls production of the hormone melatonin based on the amount of light the eyes receive. In the evening, a person’s master clock tells their brain to make more melatonin, causing sleepiness. The SCN also synchronizes the circadian rhythms in different organs and tissues across the body.
Circadian rhythms are the physical, mental, and behavioral changes an
organism experiences over a 24-hour cycle. Light and dark have the biggest influence on circadian rhythms, but food intake, stress, physical activity, social environment, and temperature also affect them. Most living things have circadian rhythms, including animals, plants, and
microorganisms. In humans, nearly every
tissue and
organ has its own circadian rhythm, and collectively they are tuned to the daily cycle of day and night.
Circadian rhythms influence important functions in the human body, such as:
- Sleep patterns
- Hormone release
- Appetite and digestion
- Temperature