2012 article

National Institute of General Medical Science

NIGMS is a part of the National Institutes of Health that supports basic research to increase our understanding of biological processes and lay the foundation for advances in disease diagnosis, treatment and prevention.

What are circadian rhythms?

Circadian rhythms are physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment. They are found in most living things, including animals, plants and many tiny microbes. The study of circadian rhythms is called chronobiology.

Are circadian rhythms the same thing as biological clocks?

No, but they are related. Our biological clocks drive our circadian rhythms.

What are biological clocks?

The biological clocks that control circadian rhythms are groupings of interacting molecules in cells throughout the body. A „master clock“ in the brain coordinates all the body clocks so that they are in synch.

What is the master clock?