| Anterior Pituitary Gland |
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The anterior pituitary (also called the '''adenohypophysis''') comprises the Anterior lobe of the Pituitary Gland and is part of the Endocrine System . Under the influence of the Hypothalamus , the anterior pituitary produces and secretes several Peptide Hormone s that regulate many physiological processes including Stress , Growth , and Reproduction . ANATOMY AND DEVELOPMENT The adenohypophysis is a Pea -size Gland Anterior to the Neurohypophysis , Caudal to the hypothalamus, and sits in the Medial aspect of the Brain . Its Blood is supplied by the Hypophyseal Portal System , and it secretes hormones into the Hypophyseal Vein . The anterior pituitary is derived from the Ectoderm of the roof of the Embryo nic Mouth . An outpocketing of this ectoderm forms Rathke's Pouch , which pinches off from the oral ectoderm and fuses with the developing Posterior Pituitary . The anterior wall of Rathke's pouch becomes the ''pars distalis'' and ''pars tuberalis'', while the posterior wall gives rise to the ''pars intermedia''. Together, the pars distalis, tuberalis, and intermedia comprise the anterior pituitary. Histology When stained by . About half of the cells are chromophobes, 40% are acidophils, and 10% are basophils. Basophilic staining cells produce the hormones that specifically act on other Endocrine Organ s, such as TSH , ACTH , FSH and LH . Acidophils produce Growth Hormone and Prolactin . Chromophobes are presumed to be "empty" cells, having already released their granules of hormone. There are also supporting glial like cells called folliculostellate cells. Physiology Five different cell types are recognised by the hormone they produce:
Electron Microscopy and Immunohistochemistry allow further identification of the hormone produced by the cells. MAJOR HORMONES SECRETED HYPOTHALAMIC RELEASING AND RELEASE-INHIBITING FACTORS Hormone secretion from the anterior pituitary gland is regulated by neurons of the Hypothalamus . Neuroendocrine neurons in the hypothalamus project Axon s to the Median Eminence , at the base of the brain. At this site, the neurons can release substances into small blood vessels that travel directly to the anterior pituitary gland (the hypothalamo-hypophysial portal vessels).
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