pituitary gland science definition

A gland at the base of the brain in vertebrate animals that is divided into two regions, anterior and posterior, each of which secretes important hormones. The anterior portion, whose secretions are directly controlled by the hypothalamus, produces hormones that regulate the function of most of the body's hormone-producing glands and organs, including the thyroid and adrenal glands. Growth hormone is also produced by the anterior pituitary. The posterior pituitary releases antidiuretic hormone (ADH) and oxytocin.