ID 231224750 © Rudzhannagiev | Megapixl.com
Sharing is not just caring, it's also about giving credit - add this image to your page and give credit to the talented photographer who captured it.:
circadian rhythm melatonin clock cycle sleep biological body chronobiology diagram health infographic internal brain chart nucleus night human routine labeled life scientific alarm chronotype daily day educational frequency hour illustration loop mental midnight model morning natural noon organic oscillation process regulation repeatedly schedule scheme structure time vector person cartoon flat