How does our body know we have a 24 hour day/night cycle?
In: 6
A significant component of it is visual. There are cells in your eye called intrinsically photoreceptive retinal ganglion cells (iprgcs) that are sensitive to blue light. These cells stimulate a certain part of the brain, the suprachiasmatic nucleus (scn), that regulates sleepiness. When there is no blue light, ipgrcs tell the scn, which causes the pineal gland to make melatonin. Melatonin makes you sleepy.
Latest Answers