Chapter 18 - Endocrine System Lecture 1 Part 2 PDF

Part 1: The Hypothalamus and Its Hormones Part 2: The Pituitary Gland and the Hormones of the Anterior Pituitary Part 3: Hypophyseal Portal System, Histology of the Pituitary Gland, & the Role of Growth Hormone Part 1:  Explain the 3 ways in which hormone release is controlled or regulated.  Fully...

Part 1: The Hypothalamus and Its Hormones Part 2: The Pituitary Gland and the Hormones of the Anterior Pituitary Part 3: Hypophyseal Portal System, Histology of the Pituitary Gland, & the Role of Growth Hormone Part 1:  Explain the 3 ways in which hormone release is controlled or regulated.  Fully describe the hypothalamus’s regulatory role, and explain the 3 main regions of control it has.  Identify and describe the hormones released by the hypothalamus, know organs these hormones target, and the function of each hormone. Part 2:  Identify and describe the anatomy of the pituitary gland, and describe the functions of the 9 hormones released by the PG.  Describe where hormone receptors are located, and which hormones reach which receptors. Part 3:  Explain the role of the hypophyseal portal system, and differentiate between the superior and inferior portion.  Describe the histology of the pituitary gland and know which histological regions release which hormones.  Explain the high degree of regulation shared by the hypothalamus and pituitary glands.  Identify and describe disorders associated with GH.     via endocrine reflexes – endocrine sensory units that trigger hormone response. (3 stimuli) 1) Humoral “stimuli” – change in extracellular fluid. 2) Hormonal stimuli – hormone stimulates the release (or inhibition) of another specific hormone. 3) Neural stimuli – sympathetic stimulation at the neuroglandular junctions (adrenal medulla).  Most secretion controlled via negative feedback. ◦ hormone release is greatest for initial response and tapers off as body nears normal range.  MP: These 3 diff types of stimuli cause release or inhibition of hormone release.   Master endocrine gland targets 3 organs via 3 ways: (18.5) 1) Anterior pituitary (via regulating hormones (RH) [either releasing or inhibiting] via blood vessels ◦ Releasing hormones stimulate production & secretion of hormones made by anterior pituitary. ◦ Inhibiting hormones reduce production & secretion.  2) Posterior Pituitary – axon terminals storing hormones of HT reach blood vessel in Post. Pit.  3) Adrenal medulla (via sympathetic nerves (ANS) – stimulates release of hormones made by adrenal medulla, which are?.      1) Releasing hormones➔ target ant. pituitary ➔ increase production and release of hormones. 2) Antidiuretic ➔ kidneys ➔ increases water hormone (ADH) retention/reabsorption = increases BP when BP low. 3) Oxytocin ➔ uterus ➔ contractions (childbirth) ➔ breasts ➔ release milk Rare positive feedback loop!      Hormones that target the ant. pituitary resulting in the production and release of a specific hormone. Thyrotropin-releasing hormone – stimulates production and release of TSH; CRH – stimulates release of ACTH by ant. pit. GnRH – stimulates release of FSH and LH, hormones that target the gonads. STUDY TABLE 18.2 – all hormones; (18.5 b for lab) Part 1: The Hypothalamus and Its Hormones Part 2: The Pituitary Gland and the Hormones of the Anterior Pituitary Part 3: Hypophyseal Portal System, Histology of the Pituitary Gland, & the Role of Growth Hormone Part 1:  Explain the 3 ways in which hormone release is controlled or regulated.  Fully describe the hypothalamus’s regulatory role, and explain the 3 main regions of control it has.  Identify and describe the hormones released by the hypothalamus, and know organs these hormones target, and the function of each hormone. Part 2:  Identify and describe the anatomy of the pituitary gland, and describe the functions of the 9 hormones released by the PG.  Describe where hormone receptors are located, and which hormones reach which receptors. Part 3:  Explain the role of the hypophyseal portal system, and differentiate between the superior and inferior portion.  Describe the histology of the pituitary gland and know which histological regions release which hormones.  Explain the high degree of regulation shared by the hypothalamus and pituitary glands.  Identify and describe disorders associated with GH.       Vice President of Endocrine Releases 9 PEPTIDE hormones that bind? Extracell. Receptors ➔ cAMP as 2nd messenger. Inferior to HT; lies within sella turcica of sphenoid. Connected to HT via infundibulum. 2 distinct lobes (18.5), which are?  Anterior pituitary produces & secretes 7 horm.; 3 distinct histological regions:  posterior pituitary secretes 2; produces 0  1 distinct regions: ◦ Pars nervosa   Stimulated by releasing hormones Ex: TRH, CRH, GnRH; Inhibited by inhibiting hormones. STUDY TABLE 18.2 – all hormones; (18.5 b for lab)      Unmyelinated axons of hypothalamic neurons. Stores & releases (DOESN’T PRODUCE) 2 hormones? Supra-optic nuclei – produce ADH = vasopressin – helps retain water/increase of blood pressure. Paraventricular nuclei – produce OXT = stimulates uterine contraction; stimulates milk ejection. Inferior HPS = carries hormones of posterior pituitary into circulation  Membrane proteins that bind specific hormone resulting in cellular changes ◦ No receptor = no effect!     Diff. cells have diff. receptors (many kinds) & diff receptors cause diff responses. Tissues have unique combination of receptors ◦ This allows 1 hormone to have varying effects from 1 tissue to another 2 locations for receptors on cells? 1) Extracellular receptors – receptors on the surface of the plasma membrane (PM) surface ◦ water soluble (peptide + AA) hormones bind here.  2) Intracellular receptors – receptors on membranes inside the cell ◦ lipid soluble (steroid + thyroid) hormones bind here