the cycle of a person`s biological clock. ideal for visual communication and institutional

afternoon art biological cartoon chronobiology circadian clock communication concept cute cycle day design disturbance dusk elements figure gland graphic health hygiene icon ideal illustration insomnia institutional isolated mascot material melatonin morning neuroendocrine newsletters night period persons pictogram pineal procedure quality rest round routine schedule sign silhouette sleep style suprachiasmatic symbol symbols synchronize system traditional vector veterinary visual wake