Write a short note on the pineal gland.

(N/A) The pineal gland is located on the dorsal side of the forebrain.
It secretes a hormone called melatonin.
Melatonin plays a very important role in the regulation of a $24$-hour (diurnal) rhythm of our body.
It helps in maintaining the normal rhythms of the sleep-wake cycle and body temperature.
Additionally,it influences metabolism,pigmentation,the menstrual cycle,and our defense capability.