A small endocrine gland sitting at the base of your brain in the sella turcica, this is the master controller of the whole endocrine system as it releases hormones that affect the function of other endocrine glands.
The pituitary gland is also related to the hypothalamus and is very close to the visual chiasma - a tumour of the pituitary gland can sometimes affect vision.
The pituitary has two lobes: the anterior pituitary lobe (a.k.a. the adenohypophysis) and the posterior pituitary lobe (a.k.a. the neurohypophysis).
The anterior lobe is a classical endocrine gland and secretes:
The posterior lobe is more like an extension of the hypothalamus and secretes: