Physiology

Rhythm is everywhere. The sun rises and sets daily.The moon follows a 28-day cycle. Seasonal changes produce variation in temperature and sunlight. The earth orbits around the solar system each year. These cycles are all examples of environmental rhythms. Sim-ilarly, all living organisms also exhibit cyclic functions, referred to as biorhythm. Every human physiological process is governed by rhythm and is time dependent. Some of these functions are familiar and easily recog-nized, for example, the daily sleep pattern. Other cyclic functions occur with no awareness, for example, heart rate variability. Rhythm is innate and genetically pro-grammed. We are born with an internal clock or en-dogenous rhythm. This ability to exhibit rhythmic func-tion is critical to environmental adaptation. Cycles, which are the basis for biorhythm, are char