 Dear students, in this topic, we shall discuss the tropic hormones of adenohypophysis in detail. The tropic hormones are the hormones which act on other endocrine tissues and regulate their secretory activity. Adenohypophysis, that is anterior pituitary gland, produces four tropic hormones. Number one, adenocortico-tropic hormone, ACTH, thyroid-stimulating hormone, TSH, also called thyrotropine-stimulating hormone, and leutinizing hormone, LH, and follicle-stimulating hormone, FSH. The adenocortico-tropic hormone, or ACTH, is a peptide hormone. That comprises a single chain of 39 amino acids. Its principal function is to regulate the secretion of carticosteroid hormones by the cortex of adenoglant. It also stimulates the secretion of androgens by adenocortex. Another major role of this is that the glandular tissues of adenocortex, that is the zona fasciculata or zona reticularis, maintain the size of them. It also stimulates the lipoprotein uptake by the adenocortex. These adenocortex cells have a major function, which is cholesterol synthesis, so that they can make carticosteroids. The lipoproteins and the requirements for the cholesterol synthesis, the uptake of the cells of these lipoproteins, ACTH, enhances them and, as a result, promotes the cholesterol synthesis and steroid hormone synthesis. In many other organisms, ACTH also plays a role in circadian rhythms. Their rhythmic activities also regulate them. Then, thyrotropin or TSH, thyroid-stimulating hormone, is a glycoprotein. Its production is stimulated by the thyrotropin-releasing hormone, TRH, from the hypothalamus. TSH is secreted throughout life, but its levels are particularly high during fast growth and development. This hormone, TSH, acts on the follicular cells of thyroid gland and helps to maintain their size. It also controls the rate of secretion of thyroid hormones, thyroxine, that is called T4, and triiodothyronine, that is called T3. These hormones, T3 and T4, in turn, control the rate of metabolic reactions in the body. The leutinizing hormone and follicle-stimulating hormone, collectively called as gonadotropins, are glycoproteins. They are released under the influence of gonadotropin-releasing hormone, GNRH, from the hypothalamus. Both these hormones work together in the reproductive systems of both males and females. These hormones act on gonads and control the growth of ovaries and testes. They also stimulate the secretion of gonadal hormones. FSH stimulates the development of ovarian follicles and regulates spermatogenesis in males. Leutinizing hormone stimulates the production of estrogen and progesterone by the ovary. This hormone also causes ovulation, that is, because of the action of leutinizing hormone and also acts in the formation of carpus luteum. In males, the leutinizing hormone is also called as ICSH, that is, interstitial cells stimulating hormone, that stimulates testosterone production by the leading cells of testes.