The pituitary gland is a gland in the brain which produces chemicals called hormones (an endocrine gland). Hormones are chemical messengers which help different organs in the body communicate with each other. The pituitary gland is one part of a messenger system.he pituitary gland is sometimes called the master gland because it controls several other hormone-releasing glands. Some of the glands the pituitary gland controls are the thyroid gland, the ovaries, the testicles (testes) and the adrenal glands.