The tiny structure, which is located quite close to the geographical center of the brain, therefore, Galen believed that it regulates the flow of thoughts himself, and Descartes, that it served as the place where there is an interaction between the body and the rational soul.
Its real function is not fully known, but now they are considered to be somewhat less cosmic scale. It plays an important role in the hormonal changes that occur during puberty. As a child, this gland releases a hormone melatonin, which inhibits sexual maturation.
At puberty the secretion of this hormone decreases, and sexual development begins.
There are also indications that this gland plays a role in the regulation of sleep in humans, and many other species it is involved in controlling the complete diurnal cycle. In some species, such as lizards, it contains light-sensitive neurons.
Also called the pineal gland of the brain.
