hypothalamus

A specialised region of the ventral diencephalon, the hypothalamus arises near the end of the segmentation period of development, and the embryonic hypothalamic region gives rise to the posterior pituitary gland as well as to a number of brain nuclei. Its most important recorded function is to link the nervous system to the endocrine system by way of the pituitary gland, also called the hypophysis. That relationship is both developmental and functional: the same region that contributes tissue to the posterior pituitary also provides the neural route through which endocrine output is governed. It is classified within the nervous system as a regional part of the brain, and the abbreviation Hy is recorded as its short designation.