The pituitary gland, or hypophysis, is an endocrine gland about the size of a pea that sits in the small, bony cavity (sella turcica) at the base of the brain. Its posterior lobe is connected to a part of the brain called the hypothalamus via the infundibulum (or stalk), giving rise to the tuberoinfundibular pathway. The posterior lobe is thus derived from neural ectoderm while the anterior lobe is derived from oral ectoderm. The anterior pituitary lobe receives releasing hormones from the hypothalamus via a portal vein system. ...