Friday, 16 September Chapter 11 The Endocrine System King DS, Sharp RL, Vukovich MD, Brown GA, Reifenrath TA, Uhl NL, Parsons KA. Effect of oral androstenedione on serum testosterone and adaptations to resistance training in young men: a randomized controlled trial. JAMA 1999; 281(21): Wednesday 1QQ to be returned on Monday Lab next week: Analyzing a research paper Pick up your photocopy from the Piano, read it before lab!

Feedback (n=25) from Wednesday’s Interactive Class: “Be the Hormone” Cons Few/no notes Not all hormones were introduced Covered less material Pros Mental image of chemical categories of hormones and relative numbers Visualization of shared properties Better able to answer chapter questions More engaging

1QQ # 5 for 8:30 1.Epinephrine is an amine hormone. 2.If you don’t know which category a hormone belongs to, the best guess is “peptide.” 3.The thyroid hormones and steroid hormones have intracellular receptors and affect gene expression and have long-lasting effects in their target cells. 4.All amine and peptide hormones are transported in the plasma in two forms: bound and free. 5.Thyroid hormones and steroid hormones are stored in vesicles and secreted later. Each True/False Question counts 2 points. Answer all five.

1QQ # 5 for 9:30 1.Dopamine is an amine hormone. 2.If you don’t know which category a hormone belongs to, the best guess is “steroid.” 3.The thyroid hormones and steroid hormones have cell- surface receptors and usually have long-lasting effects in their target cells. 4.T3 and T4 and peptide hormones are transported in the plasma in two forms: bound and free. 5.Catecholamines and peptide hormones are stored in vesicles and secreted later. Each True/False Question counts 2 points. Answer all five.

Endocrine Organs (Table 11-1) Pituitary Gland Thyroid Gland Pancreas Gonads Gastrointestinal Tract Heart Kidney Hypothalamus Liver Etc. Hormone: chemical messengers carried by blood to target cells upon which they act. Only those cells having receptors Can respond to a given hormone Hormone Paracrine agent Autocrine agent Neurotransmitter Neuromodulator

Fig Thyroid hormone stimulates production of beta-adrenergic receptors, Makes target cells more sensitive to EPI Permissive effect

3 Chemical Classes of Hormones 1: Amine hormones (from amino acid tyrosine) –Thyroid hormones –Adrenal medullary hormones (catecholamines) 2: Peptide hormones (peptides & proteins) 3: Steroid Hormones (derivatives of cholesterol) Why does the chemical class matter?

Fig Catecholamines soluble in plasma Thyroid Hormones Not soluble in plasma, bound & free Amine Hormones Adrenal medulla NT

Fig Steroid hormones not soluble in plasma, not storable in vesicles Target cells have intracellular receptors. Changes is gene expression. Timecourse? Bound & Free

Fig Peptide Hormones Examples of Peptide Hormones: Insulin, glucagon prolactin, erythropoietin, parathyroid hormone, gastrin, leptin, growth hormone, oxytocin, vasopressin, FSH, LH, GHRH, and many more! Cell surface receptors on target cells Guess peptide! Soluble in plasma e.g. Beta cell

Know Table 11-2 p 323 Hormone class Major form in plasma Location of receptors Signal transduction mechanisms Rate of excretion / metabolism

Questions so far?

Fig Adrenal Glands Part of Sympathetic Nervous System How do adrenal cortex cells “know” which hormone to synthesize from cholesterol?

Hormones of the Adrenal Cortex Glucocorticoids Mineralicorticoid Androgens DHEA “Andro” What regulates the secretion of cortisol and aldosterone?

Fig Gonadal Steroids (not adrenal cortex) King DS, Sharp RL, Vukovich MD, Brown GA, Reifenrath TA, Uhl NL, Parsons KA. Effect of oral androstenedione on serum testosterone and adaptations to resistance training in young men: a randomized controlled trial. JAMA 1999; 281(21): Estrogens

Fast if free Slow if bound Be able to give Examples. T4 to T3 and Testosterone to Estradiol Ex: Renin What happens to hormones once released?

Renin-angiotensin-aldosterone Angiotensinogen from liver, an ever-present plasma protein Renin Angiotensin I Angiotensin converting enzyme (ACE) Angiotensin II Thirst Arterial smooth muscle … vasoconstriction…increase blood pressure Zona Glomerulosa of Adrenal Cortex Aldosterone Promotes Na+ retention in Kidney Renin is an enzyme released from kidney cells into bloodstream, its “substrate” is a plasma protein called Angiotensinogen. BV & BP

Aldosterone Na+ reabsorption in kidney Plasma volume Blood pressure Renin from Juxtaglomerular cells in Kidney Multi-step process involving Angiotensin I and II (-) Angiotensin II thirst Drink vasoconstriction K+ in plasma _______ Blood Pressure

Fast if free Slow if bound Be able to give Examples. T4 to T3 and Testosterone to Estradiol Ex: Renin What happens to hormones once released?

Factors that affect hormone secretion Recall example: beta cells of Islets of Langerhans Secretion is usually pulsative, may be diurnal. Integrator! Na+, K+, Ca++, Glucose, etc. NE (sympathetic) ACh (parasympathetic) etc. Tropic

Thyroid Gland TH =T3 and T4 Fenestrated Capillary (typical of endocrine glands) S1

Synthesis, Storage and Secretion of T3 and T4 Roles of TSH (Thyroid Stimulating Hormone) TH increases cell metabolism & heat production (BMR) Tropic: directs controls, regulates Trophic: growth S2

Fig a Receives input from many regions of brain; many factors Affect its function Homeostatsis center. S3

Fig b Vasopressin (= Antidiuretic hormone) Oxytocin Neurohypophysis Adenohypophysis 6 S4

Tropic hormones control the function Trophic hormones promote survival and growth of targets Releasing HormoneRelease-inhibiting Hormone Hypothalamo-hypophyseal portal system A A S S P P PPP PP PPPP S 6

Tropic hormones control the function Trophic hormones promote survival and growth of targets Releasing Hormone Release Inhibiting Hormone Long-loop negative feedback Short-loop Neg. Feed. S 7