Lobular organ, each instance of which is an epithelial body located at the base of some brain in the sella turcica, attached by a stalk to some hypothalamus, from which it receives an important neural and vascular outflow. It consists of two lobes of differing embryonic origin, the anterior lobe (adenohypophysis), which secretes most of the hormones, and the posterior lobe (neurohypophysis), which stores and releases neurohormones that it receives from the hypothalamus.