The adenohypophysis is the anterior lobe of the pituitary gland and consists of the distal, intermediate, and infundibular parts. The adenohypophysis develops from a group of cells, Rathke’s pouch, that migrate toward the center of the base of the brain from the roof of the embryonic oral cavity. The post-embryonic anterior lobe contains five cell types that produce six hormones in response to the presence of releasing hormones produced by the hypothalamus: corticotropes make corticotropin (adrenocorticotropichormone, ACTH), gonadotropes make follitropin (follicle stimulating hormone, FSH) and luteotropin (luteinizing hormone, LH), lactotropes (mammotropes) make prolactin (PRL), somatotropes make somatotropin (growth hormone, GH), and thyrotropes make thyrotropin (thyroid stimulating hormone, TSH). These hormones are central to maintaining either metabolic balance in essential physiological systems (ACTH, GH, TSH) or are central to successful reproduction (FSH, LH, PRL).