What is a Circadian Rhythm? [Chronobiology]
Most living beings, even algae, have a special biological system that keeps their body in sync with day and night, their circadian rhythm . The way it does this is by responding to light or darkness, e.g. this is why we sleep at night and are awake during the day. The term "circadian" is derived from the latin " circa diem" or "approximately a day". So what produces/drives these circadian rhythms? The answer is BIOLOGICAL CLOCKS These clocks are present in most cells, tissues and organs and are composed of proteins which all interact throughout the body. The biological clocks are all controlled and coordinated by a MASTER CLOCK (group of nerve cells in the hypothalamus called the superahiasmatic nucleus (SCN) which are connected to our optic nerves to detect light. The main regulator of the circadian rhythm is in our hypothalamus: "a region of the forebrain below the thalamus which coordinates both the autonomic nervous system and the ...