Description :

Biological clocks are fundamental to the functioning of life and to the organization and coordination of behavior simple behavioral functions such as timing active and inactive periods during the day night cycle to maximize productivity and minimize risk rely on internal clock functions. Biological clocks are known to affect hormonal secretions and responses in a wide variety of experimental animals and in humans very regular 24 h fluctuations in circulating hormone levels can be observed some behavioral responses to hormone administration vary in amplitude according to the time of day in mammals the brains circadian clock . Where is the biological clock the master clock is an area called the suprachiasmatic nucleus a small region of the brain found within the anterior hypothalamus it exerts hormonal control to peripheral clocks that have been described in many cell types including everything from heart to liver to fat tissues