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2. Functional Physiology of Adrenal Medullary Hormones Presentedby AbdulQahar Subject:Endocrinology 3. Adrenal Glands adrenal cortex adrenal medulla 4. Adrenal Glandslocated above each kidneyinner adrenal medullaouter adrenal cortex 5. Types of hormones-1 Amine hormones: Hormones derived from the amino acid tyrosine.These include epinephrine, norepinephrine and thyroid hormone. Epinephrine and norepinephrine are produced by the adrenal medulla water soluble Thyroid hormone is produced by the thyroid gland lipid soluble 6. Adrenal medullaPart of autonomic nervous systemSpherical chromaffin cells are modified postganglionic sympathetic neurons Amine hormonesSecrete epinephrine and norepinephrine Fight, flight, frightVesicles store the hormones6 7. Hormones of adrenal medulla noradrenaline 20% 1.2 - 3.4 nmol/l5 - 6 fold increase exerts biological actionadrenaline80%0.1 - 0.8 nmol/l2 fold increase can elicit physiological responseThese hormones prepare the body to deal with short- term stress. 8. Amine hormones: derived from tyrosine Epinephrine, norepinephrine and dopamine are water soluble and are synthesized and secreted like peptide hormonesThyroid hormones are produced by modification of a tyrosine residue contained in thyroglobulin, post-translationally modified to bind iodine, then proteolytically cleaved and released as T4 and T3. T3 and T4 then bind to thyroxin binding globulin for transport in the blood 9. Synthesis of catecholamines 10. Why are these hormones important to the maintenance of homeostasis? Keeps a good balance between sodium and water levels in the body. Helps with the breakdown of amino acids which maintains normal blood pressure. Acids in puberty, keeps the body alert and stimulated when necessary. 11. Hormones of medullary catacholamines Epinephrine,norepinephrine and DOPA Nature derivatives of tyrosine Excretion is regulated by sympathetic nervous system and brain cortex 12. Functions: Stress hormones. Contraction of vessels, increase the blood pressure, accelerate pulse. Contraction of uterus muscles. Epinephrine relaxes the muscles of bronchi and intestine. On carbohydrate metabolism: -activates the decomposition of glycogen in liver and muscles -activates glycolysis, PPC, TAC and tissue respiration On protein metabolism -accelerate the decomposition of proteins On lipid metabolism -activates lipase, mobilization of lipids and their oxidation 13. Hypothalamus and Adrenal Glands in Stress ResponseFigure 9.12 14. Adrenal (Suprarenal) Glands Lie superior to each kidney Comprised of two parts outer adrenal cortex & inner adrenal medulla 15. Adrenal Medulla hormones epinephrine (adrenaline) and norepinephrine (noradrenaline) produced during times of stressreleased into blood, causes glycogen to be converted to glucose, sugar levelsspeeds up heart & breathing rates, cell metabolism, and causes pupil to dilate (more light into retina) 16. Hypothalamus and Adrenal Glands in Stress ResponseFigure 9.12 17. Mechanism of Adrenal Medulary Hormones. 18. Adrenal Gland Anatomy was first described in 1563. Is located above (or attached to) the upper pole of the kidney. Is pyramidal in structure and weighs ~ 4 g. Consists of the adrenal cortex and adrenal medulla Activities are regulation of fluid volume and stress response 19. The General Adaptation Syndrome 20. Activity of Epinephrine 21. Mechanism: Norepinephrine Release and Recycling 22. Review of Efferent Pathways: Motor and Autonomic 23. Adrenal medullaPart of autonomic nervous systemSpherical chromaffin cells are modified postganglionic sympathetic neurons Amine hormonesSecrete epinephrine and norepinephrine Fight, flight, frightVesicles store the hormones26 24. Catechalomines: Activity Stimulates the fight or fight reactionIncreased plasma glucose levelsIncreased cardiovascular functionIncreased metabolic functionDecreased gastrointestinal and genitourinary function 25. Identify Feedback Mechanisms and Antagonistic Hormones. When your body is in need of epinephrine or adrenaline, hormones are secreted that release epinephrine, when there is too much epinephrine in the body then a hormones is released that stops the secretion of epinephrine. Feedback Mechanism: A process in which the level of one substance influences the level of another substance. Antagonistic Hormones: Hormones that act to return body conditions to within acceptable limits from opposite extremes are called.