ANATOMY 2

• The anterior pituitary gland secretes a tropic hormone, which travels in the blood to the target endocrine cell.
• The hormone from the target endocrine cell travels to its target.
• The hormone from the target endocrine cell also has a positive-feedback effect on the anterior pituitary and increases secretion of the tropic hormone.
• The pituitary gland and hypothalamus integrate NS and ES, and the pituitary gland secretes nine major hormones that regulate numerous body functions and the secretory activity of several other endocrine glands.
• T3 and T4 act on target tissues to produce a response.
• TSH causes increased synthesis and release of T3 and T4 into the general circulation.
• T3 and T4 also have an inhibitory effect on the secretion of TRH from the hypothalamus and TSH from the anterior pituitary.
• The hypothalamus regulates the secretory activity of the pituitary gland in response to other hormones, sensory information, and emotions.
• The pituitary gland is located to the base of the brain, inferior to hypothalamus.
• The pituitary gland is connected to the hypothalamus by the infundibulum.
• The pituitary gland has two lobes: the Anterior Pituitary Gland (adenohypophysis) and the Posterior Pituitary Gland (neurohypophysis).
• Adrenocorticotropic Hormone (ACTH) targets the adrenal cortex, increasing glucocorticoid hormone secretion.
• Two neurohormones, Growth Hormone-Releasing Hormone (GHRH) and Growth Hormone-Inhibiting Hormone (GHIH), are released from the hypothalamus to regulate the secretion of Growth Hormone.
• Increased GHRH and reduced GHIH act on the anterior pituitary and result in increased GH secretion.
• Low blood glucose levels and other stressors increase the release of GHRH, and decrease the release of GHIH, from the hypothalamus.
• Growth Hormone has indirect effects on increasing the production of somatomedins, which are best known as insulin-like growth factors (IGFs), stimulating growth in cartilage and bone and increasing the synthesis of protein in skeletal muscles.
• Growth Hormone has direct effects on determining how tall a person becomes and regulating metabolism.
• Growth Hormone (GH) acts on target tissues.
• GHRH and GHIH travel through the hypothalamohypophysial portal system to the anterior pituitary.
• Increasing GH and somatomedins have a negative-feedback effect on the hypothalamus, resulting in decreased GHRH and increased GHIH release.
• Growth Hormone (GH) or Somatotropin is most tissues' target, increasing growth, amino acid uptake and protein synthesis, lipid breakdown and release of fatty acids from cells, glycogen synthesis, blood glucose levels, somatomedin production, and slowing protein breakdown.
• Thyroid-Stimulating Hormone (TSH) targets the thyroid gland, increasing thyroid hormone secretion.
• The Posterior Pituitary Gland (neurohypophysis) is continuous with the hypothalamus in the brain and forms from an outgrowth of the inferior part of the brain (distal end of infundibulum that enlarges).
• Addison disease is a chronic adrenocortical insufficiency, where the adrenal cortex degenerates, usually due to an autoimmune condition.
• Luteinizing hormone (LH) targets ovaries in females and testes in males, stimulating ovulation and progesterone production in ovaries and testosterone synthesis and support for sperm cell production in testes.
• Releasing hormones and inhibiting hormones pass through the hypothalamohypophysial portal system to the anterior pituitary.
• Prolactin targets ovaries and mammary glands in females, increasing milk production in lactating women and increasing the response of follicle to LH and FSH.
• Prolactin is regulated by two neurohormones of hypothalamus: Prolactin-releasing hormone (PRH) and Prolactin-inhibiting hormone (PIH).
• Releasing hormones and inhibiting hormones (green and red circles) leave capillaries and stimulate or inhibit the release of hormones (yellow squares) from anterior pituitary cells.
• The anterior pituitary gland and hypothalamus work together to regulate the release of anterior pituitary hormones, with stimuli within the nervous system regulating the secretion of releasing hormones and inhibiting hormones from the hypothalamus.
• Prolactin is also secreted by the mammary glands of lactating females, enhancing progesterone secretion by the ovaries after ovulation.
• Endorphins are hormones that target the brain, providing analgesia and inhibiting gonadotropin-releasing hormone secretion.
• Melanocyte-stimulating hormone (MSH) targets melanocytes in the skin, increasing melanin production in melanocytes to make the skin darker in color.
• Follicle-stimulating hormone (FSH) targets follicles in ovaries in females and seminiferous tubules in males, stimulating follicle maturation and estrogen secretion in ovaries and sperm cell production in testes.
• Lipotropins are hormones that target adipose tissues, increasing lipid breakdown.
• Stimulus for Addison disease is environmental stress.
• The Posterior Pituitary Gland (neurohypophysis) is a part of the nervous system and its hormones are called Neuropeptides, or neurohormones.
• The male reproductive system consists of the testes, epididymis, vas deferens, seminal vesicles, ejaculatory duct, bulbourethral gland, prostate gland, and penis.
• The vas deferens is responsible for the transportation of sperm from the epididymis to the ejaculatory duct.
• Homeostatic mechanisms attempt to counteract stress, and when they are successful, the internal environment remains within normal physiological limits.