Releasing Hormones.. Anterior Pituitary Hormones : ? Posterior Pituitary Homones
ID: 301240 • Letter: R
Question
Releasing Hormones.. Anterior Pituitary Hormones : ? Posterior Pituitary Homones HYPOTHALAMUS Hypothalamic- Hypophysial Portal System Pituitary Stalk Anterior __//O ? Pituitary Posterior Pituitary Gland Gland ACTH Adrenal Gland Thyroid Gland TSH Kidneys & Blood Vessels ADH - Testes & Ovaries LH G H Prolacti Oxytocin Uterus & Muscle, Tissue, & Bone Glands Mammary Gland FIG. 1. Secrétion of hypothalamie hormones. Hypothalamic releasing hormones travel down the hypothalamic- hypophysial portal system to the anterior pituitary gland, where they stimulate the synthesis and release of anterior pituitary hormones [adrenocorticotropin hormone (ACTH), uhyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), growth hormone (GH), and prolactin. In contrast, the posterior pituitary gland does not require releasing hormones, because the. bypothalamus synthesizes and secretes both anti-diuretic hormone (ADH) and oxytocin.Explanation / Answer
1.the TRH (thyrotropin releasing hormone is the hormone stimulating the release of prolactin and TSH from anterior pituitary. it is poduced in hypothalamus.
The CRH( corticotropin releasing hormone) is secreted by PVN( paraventricular nucleus) of hypothalamus in response to stress. it stimulated the ACTH syntheis and functioning in pituitary .
The GnRH( gonadotropin releasing hormone) is also secreted by the hypothalamus to stimulate the synthesis and secretion of the gonadotropins which are FSH (follicle stimulating hormone) and LH ( luteinizing hormone).
2. the TSH pituitary hormone TSH targets the thyroid gland, the ACTH targets the adrenal glans and the LH targets the ovarian follicle and interstitial testes cells.
3. the TSH of pituitary causes thyroid to release T3 and T4 metabolic stimulants.
The ACTH in pituitary targeting adrenal glands regulates the steroid synthesis.
the LH targets the FSH to cause maturation of graffian follicles and spermatogenesis.
4. The concentration of hormones in plasma shifts on the basis of various stimulis which are regulated by three types of mechanism such as feedback cycles( positive and negative) and cyclic changes. if a long term reduction occurs in a hormone in particular tissue it can increase the density of receptors thus causing sensitization of the cell. if the hormone concentration is elevated for a long time it can inactivate the receptors.