Pituitary gland secretes hormones. All releasing hormones (-RH) referred to, can also be referred to as releasing factors (-RF). Somatotropes: Corticotropes: Thyrotropes: Gonadotropes: Lactotropes: These hormones are released from the anterior pituitary under the influence of the hypothalamus. Hypothalamic hormones are secreted to the anterior lobe by way of a special capillary system, called the hypothalamic-hypophysial portal system. There is also a non-endocrine cell population called folliculostellate cells. The intermediate lobe synthesizes and secretes the following important endocrine hormone: The posterior pituitary stores and secretes (but does not synthesize) the following important endocrine hormones: Magnocellular neurons: Hormones secreted from the pituitary gland
Pituitary gland often not clearly marked. In elasmobranchs there is an additional, "ventral lobe" beneath the anterior pituitary proper. The arrangement in lampreys, which are among the most primitive of all fish, may indicate how the pituitary originally evolved in ancestral vertebrates. Here, the posterior pituitary is a simple flat sheet of tissue at the base of the brain, and there is no pituitary stalk. Rathke's pouch remains open to the outside, close to the nasal openings. Closely associated with the pouch are three distinct clusters of glandular tissue, corresponding to the intermediate lobe, and the rostral and proximal portions of the