Circadian Rhythms

Circadian Rhythms
Definition
[Circa => about; dies => day]
Biorhythms may occur, showing periodicity of about 24-Hours. These are called Circadian Rhythm, which means about one day, so they are also called diurnal rhythms.
Causes of Biorhythm
Biorhythms occurs due to the following reasons.
1. Exogenous Stimuli
2. Endogenous Stimuli
1. Exogenous Stimuli
There may be direct response to various changes in the external (exogenous) stimuli.
2. Endogenous Stimuli
These rhythms can be controlled internally by an efficient time measuring system and are independent of light and temperature effects. These types of rhythms are called endogenous.