BM1011 Module 8 Endocrine System Lecture 2 PDF

BM1011 The Endocrine System: Module 8 Part 3 - Adrenaline and Cortisol Daniel Browne [email protected] Structure of Module 2: Learning Objectives The Endocrine System Define what a hormone is and how hormones are classified Illust...

BM1011 The Endocrine System: Module 8 Part 3 - Adrenaline and Cortisol Daniel Browne [email protected] Structure of Module 2: Learning Objectives The Endocrine System Define what a hormone is and how hormones are classified Illustrate the mechanisms of action of different hormones Describe the control of hormone release Apply the principles of hormone secretion to: Antidiuretic hormone (ADH) The Renin-Angiotensin-Aldosterone system (RAAS) The release of Adrenaline The release of Cortisol by the Hypothalamus-Pituitary-Adrenal (HPA) axis. The regulation of blood glucose with Insulin and Glucagon jcu.edu.au Recap: Organ systems of the body: Communication The Endocrine System Organs: Endocrine glands Most organs Function: Transmit chemical signals (hormones) into blood regulate body function jcu.edu.au Recap: Hormone Communication jcu.edu.au BioRender Recap: Endocrine Glands Pineal gland Hypothalamus Pituitary gland The HPA Axis Thyroid gland Stress response Parathyroid glands Hypothalamus (on dorsal aspect of thyroid gland) The 4 F’s Thymus temperature, hunger thirst Adrenal glands Pituitary Glands Master glad: growth, Pancreas reproduction Adrenal Glands Gonads Ovary (female) Metabolism, immune function, Testis (male) stress jcu.edu.au Recap: ADH Negative Feedback Loop Hypothalamus senses higher solutes ADH secreted into blood by posterior pituitary gland ADH stimulated kidneys to reabsorb more water Water level returns to normal range Reverse also occurs. Both negative feedback jcu.edu.au Recap: The renin-angiotensin-aldosterone system (RAAS) Complex hormonal cascade primarily involved in regulating blood volume and pressure Important drug target to influence blood pressure Hypertension related cardiovascular disease still a major killer of Australians jcu.edu.au Stress Response: Fight or Flight Hyperarousal due to a perceived threat to survival Autonomic Nervous System Hormonal response Whole body response Promote physiology required for immediate action Sharpen senses sandiegozoo.org Increased alertness Suppress non-urgent physiology Immune function Digestion jcu.edu.au Stress Response: Fight or Flight Promote physiology required for immediate action Well oxygenated, nutrient rich blood is delivered to skeletal muscles Heart rate and myocardial contractility are increased Widespread smooth muscle vasoconstriction (Gastrointestinal sandiegozoo.org & Renal) Bronchodilation in the lungs Enhanced glycogenolysis and gluconeogenesis (Brain) Increased sweating (Thermal regulation) Pupil dilation jcu.edu.au Active Endocrine Glands Pineal gland Hypothalamus 1. Danger sensory input enters Pituitary gland hypothalamus (4F’s) Thyroid gland Parathyroid glands 2. Hypothalamus activates the (on dorsal aspect of thyroid gland) Sympathetic Nervous System Thymus 3. Sympathetic nervous system Adrenal glands directly innervates the adrenal medulla Pancreas Adrenaline and Gonads Norepinephrine released! Ovary (female) Testis (male) Fast jcu.edu.au © 2019 Pearson Education Ltd. Adrenaline (Epinephrine) Water soluble (Hydrophilic) Amine hormone (Tyrosine) Phe or Tyr → Norepinephrine → Epinephrine Does not have a negative feedback loop Epinephrin concentration in Adults Action cancelled by secretion and liver Resting: 10 ng/L metabolism Exercising: 100ng/L Binds to adrenergic receptors Fight/Fight: 500ng/L Class of G-protein coupled receptors jcu.edu.au Adrenergic receptors vs Epinephrine On almost every cell in the body Large number of sub-types Epinephrine binds to them all! α1 - Smooth muscle contraction, mydriasis α2 - Mixed smooth muscle effects β1 - Increased cardiac chronotropic and inotropic Epinephrin concentration in Adults effects (Increase frequency of AV node impulses) Resting: 10 ng/L β2 - Broncho- and vaso- dilation of blood vessels Exercising: 100ng/L supplying skeletal muscles Broad Class of Medications Fight/Fight: 500ng/L Alpha/beta blockers β3 - increase lipolysis Agonists & Antagonists jcu.edu.au Agonists vs Antagonists Come back to this is BM1022 jcu.edu.au Noradrenaline (Norepinephrine) Water soluble (Hydrophilic) Phe or Tyr → Norepinephrine → Epinephrine The main neurotransmitter of the sympathetic nervous system Increases cognitive alertness Norepinephrin concentration in Adul Promotes restlessness & anxiety Sleeping: lowest Action cancelled (usually) by reuptake Awake: Standard secretion and liver metabolism Fight/Fight: Highest Drugs such as cocaine, Ritalin, amphetamines act as reuptake inhibitors jcu.edu.au Summary: Release of Adrenaline and Norepinephrine jcu.edu.au Summary: Release of Adrenaline and Norepinephrine jcu.edu.au Active Endocrine Glands Pineal gland Hypothalamus 1. Danger sensory input enters Pituitary gland hypothalamus (4F’s) Thyroid gland Parathyroid glands 2. Hypothalamus releases (on dorsal aspect corticotropin-releasing hormone of thyroid gland) (CRH) Thymus Adrenal glands 3. The pituitary gland releases adrenocorticotropic hormone Pancreas (ACTH) Gonads 4. ACTH then prompts the adrenal Ovary (female) Testis (male) cortex to produce cortisol Slower / Chronic jcu.edu.au © 2019 Pearson Education Ltd. Corticotropin-releasing hormone Water soluble (Hydrophilic) (41aa) Peptide Hormone Produced in the hypothalamus in response to stress Anterior CRH carried in hypothalamo- pituitary hypophyseal portal system. to the anterior lobe of the pituitary jcu.edu.au Adrenocorticotropic hormone Water soluble (Hydrophilic) Poly-Peptide Hormone Produced in the anterior lobe of the pituitary in response to CRH stimulation Anterior Binds to adrenocorticotropic pituitary hormone receptors (ACTH) Primarily in adrenal cortex jcu.edu.au Cortisol Lipid soluble (Hydrophobic) Steroid Hormone Released in response to stress (and low glucose) Glucocorticoid - Binds to Glucocorticoid receptor Anti-inflammatory Promote arousal and cognition jcu.edu.au Summary: Release of Glucocorticoids (Cortisol) jcu.edu.au Summary: Release of Glucocorticoids (Cortisol) jcu.edu.au Structure of Module 2: Learning Objectives The Endocrine System Define what a hormone is and how hormones are classified Illustrate the mechanisms of action of different hormones Describe the control of hormone release Apply the principles of hormone secretion to: Antidiuretic hormone (ADH) The Renin-Angiotensin-Aldosterone system (RAAS) The release of Adrenaline The release of Cortisol by the Hypothalamus-Pituitary-Adrenal (HPA) axis. The regulation of blood glucose with Insulin and Glucagon jcu.edu.au 10 minute break jcu.edu.au Getty Images The regulation of blood glucose Hyperglycemia: cardiovascular disease, nerve damage, kidney damage, and vision problems. Glucose Carbohydrate Monosaccharide ≥7 mmol/L 4-6 mmol/L ≤4 mmol/L Hypoglycemia: fatigue, confusion, tremors, seizures ChatGPT: Image Generator jcu.edu.au The pancreas Located behind the stomach in the abdomen Acinar Cells: Produce enzyme rich juice which is carried to the small intestine for digestion Pancreatic Islets: cells clusters that produce hormones Alpha cells: Produce Glucagon Beta cells: Produce Insulin jcu.edu.au Glucagon Water soluble (Hydrophilic) (29aa) Poly-Peptide Hormone Extremely potent hyperglycemic agent One molecule can cause the release of 100,000,000 glucose molecules Decreasing Blood [Glucose] Binds to the glucagon receptor Increasing Blood [Glucose] (liver) jcu.edu.au Glucagon: Glycogenolysis Binds to the glucagon receptor (Liver) Signal Transduction Activate Glycogen phosphorylase Decreasing Blood [Glucose] Increasing Blood [Glucose] Glycogen Glucose Carbohydrate Carbohydrate Polysaccharide Monosaccharide jcu.edu.au Glucagon: Gluconeogenesis Binds to the glucagon receptor (Liver) Signal Transduction Activate Protein kinase A Decreasing Blood [Glucose] Lactate Increasing Blood [Glucose] Glycerol Amino Acids Glucose (Ala, Glut) Carbohydrate Monosaccharide jcu.edu.au Insulin Proinsulin cleaved in beta cells to produce Insulin (51aa) Protein Hormone Enzymes Proinsulin Insulin Secretory Vesicle jcu.edu.au Insulin: Release Elevated blood glucose levels Rising levels of amino acids/fatty acids Stimulation with parasympathetic nervous system (Indirectly) hyperglycemic hormones (eg - glucagon) Insulin jcu.edu.au Insulin: Effects Binds to a surface receptor Tyrosine protein kinase Not G-protein coupled (still signal transduction!) Glucose → Glycogen Glucose → Fatty acids Increase glucose uptake (almost all cells) Facilitate membrane transport Inhibits the effect of Glucagon Insulin Glycogenolysis Gluconeogenesis jcu.edu.au Homeostasis of Blood Glucose Blood glucose rises Pancreas secretes insulin Stimulated cellular glucose uptake Glucose to Glycogen in liver Blood glucose falls Pancreas secretes glucagon Stimulates glycogen lysis to glucose jcu.edu.au Diabetes Mellitus Type 1 Diabetes Insulin not produced Type 2 Diabetes Insulin not effective jcu.edu.au Diabetes Mellitus Cardinal Symptoms Polyuria - excessive urine production (glucose inhibits water reabsorption from kidneys) Polydipsia – excessive thirst (caused by polyuria) Polyphagia – excessive hunger (cause by reduced uptake of glucose to tissue) jcu.edu.au Diabetes Mellitus Treatment Type I - beta cells almost always gone by diagnosis Insulin injections Type II - extremely high twin concordance. Exercise/weight loss & diet Insulin injections jcu.edu.au  Patient Scenario A patient who weighs 107 kg needs to be given a dose of insulin equivalent to 300 milliunits per kg. If the infusion solution provided contains 50 units of insulin per mL, they need to receive an infusion of ____ mL of the insulin solution. (Write your answer with TWO decimal places and NO units). 107 kg 32,100 mU 32.1 U x 300 mU / kg 1,000 mU / U 50 U / mL 32,100 mU 32.1 U 0.642 mL 0.64 jcu.edu.au Reproductive Endocrine Pineal gland Hypothalamus Glands Pituitary gland Thyroid gland Next Week Parathyroid glands (on dorsal aspect of thyroid gland) Thymus Adrenal glands Pancreas Gonads Ovary (female) Testis (male) jcu.edu.au © 2019 Pearson Education Ltd. Structure of Module 2: Learning Objectives The Endocrine System Define what a hormone is and how hormones are classified Illustrate the mechanisms of action of different hormones Describe the control of hormone release Apply the principles of hormone secretion to: Antidiuretic hormone (ADH) The Renin-Angiotensin-Aldosterone system (RAAS) The release of Adrenaline The release of Cortisol by the Hypothalamus-Pituitary-Adrenal (HPA) axis. The regulation of blood glucose with Insulin and Glucagon jcu.edu.au  Questions? jcu.edu.au jcu.edu.au