Our last seminar!!! Chapter 19 Endocrinology

1. Our last seminar!!!Chapter 19Endocrinology

2. Review of errors

3. Endocrinology • A subspecialty of internal medicine • The study of the function of the endocrine glands • Endocrinologist: a physician who diagnoses and treats hormone problems

4. Anatomy of the Endocrine System • Endocrine glands • Located in different parts of the body • Not connected to each other • Glands release hormones • Hormones regulate bodily processes

5. Endocrine Glands • Pituitary (hypophysis) • Located below hypothalamus • Called the “master gland” • Release of hormones controlled by the hypothalamus • Divided into anterior and posterior lobes

6. Anterior gland • Prolactin (PRL) • Growth hormone (somatotropin) (GH) • Adrenocorticotropic hormone (corticotropin) (ACTH)

7. Anterior gland (continued) • Thyroid-stimulating hormone (thyrotropin) (TSH) • Gonadotropins: • Follicle-stimulating hormone (FSH) • Luteinizing hormone (LH) • Interstitial cell-stimulating hormone (ICSH)

8. Posterior gland • Oxytocin (OC) • Antidiuretic hormone (vasopressin) (ADH) • Pineal gland • Located in third ventricle of the brain • Produces melatonin (regulates body’s clock)

9. Thyroid gland • A butterfly-shaped gland • Two lobes wrap around the trachea • Regulates the body's metabolism • Produces T3, T4 and calcitonin • T3 and T4 regulate metabolism • Calcitonin regulates high balance of calcium

10. Parathyroid glands • Four glands located on the back of each lobe of the thyroid gland • Regulate low balance of calcium • Thymus gland • Located behind the sternum • Part of both the immune system and endocrine system • Releases thymosin which helps T cells to mature

11. Adrenals (suprarenal glands) • Lie on top of each kidney • Adrenal cortex: upper region of the adrenal gland • Cortisol • Corticosterone • Aldosterone

12. Adrenal medulla: Inner part (core) of the adrenal gland • Releases “fight or flight” hormones • Catecholamines (epinephrine and norepinephrine): • Increases heart rate, blood flow to the muscles and brain

13. Pancreas • Part of both the digestive system and endocrine system • Regulates blood sugar • Islets of Langerhans: Produce insulin and glucagon • Insulin: Rising levels of blood sugar (hyperglycemia) • Glucagon: Low levels of blood sugar (hypoglycemia)

14. Gonads • The sex glands that make sex cells • Ovaries in females and testes (testicles) in males • Ovaries: estrogen and progesterone • Testes (testicles): testosterone and inhibin

15. Diseases and Disorders of the Endocrine System Endocrine disorders: production of too much or too little of a specific hormone Generally managed by hormone replacement therapy or therapy to reduce the activity of the gland

16. Pituitary Disorders • Dwarfism: Low output of growth hormone during childhood • Gigantism: High output of growth hormone during childhood • Acromegaly: High output of growth hormone middle-aged adults • Treatments • Surgery: Transsphenoidal adenectomy • Medical therapy to control production of growth hormone

17. Hypopituitarism: loss of hormone secretion of anterior pituitary Panhypopituitarism: all hormones produced by the pituitary are affected • Treatment: restore pituitary to normal function through hormone therapy or surgical removal of the pituitary Hyperparathyroidism • Parathyroid hormone (PTH) secreted, resulting in (hypercalcemia) • Treatment: Surgical removal (parathyroidectomy)

18. Adrenal Disorders • Cushing syndrome (hypercortisolism) • Cushing disease: when Cushing syndrome is caused by pituitary tumor • Treatments • Adrenalectomy or removal of pituitary gland tumor • Medications to control the production of excess cortisol

19. Addison disease (adrenal insufficiency): hyposecretion of cortisol • Treatment: oral hormone replacement Pheochromocytoma: benign tumor of the adrenal medulla • Treatment: surgery to remove the pheochromocytoma; medications to control the hypersecretion of catecholamines

20. Diabetes Mellitus (DM) Body fails to manufacture or properly use insulin Symptoms: Polyuria, polydipsia, polyphagia, weight loss, blurred vision • Types • Type 1 (IDDM) • Pancreas undergoes autoimmune attack, rendering it useless for making insulin • Type 2 (NIDDM) • Pancreas can still produce insulin but not in properamounts (insulin resistance)

21. Gestational diabetes:occurs during pregnancy only • Secondary diabetes:from another body condition or disease • Treatment: lifestyle changes and medications

22. Types of Medications • Sulfonylureas • Biguanides • Alpha-glucosidase inhibitors • Thiazolidinediones • Drug combinations: Combinations of therapies in one pill

23. Types of insulin • Rapid-acting • Short-acting • Intermediate-acting • Long-acting • Very long-acting • Premixed: two types of insulins mixed together in one bottle

24. Pancreas transplantation Diabetes insipidus: caused by deficiency of ADH, body cannot retain water • Called “water” diabetes to distinguish it from DM or“insulin” diabetes • Treatment: antidiuretic medications

25. Diagnostic Studies and Procedures • Laboratory tests • Calcium: level of calcium in the blood • Catecholamines: adrenal medulla function • Cortisol: status of adrenal function • Glucose tolerance test (GGT): blood sugar at present moment • Glycosylated hemoglobin (hemoglobin A1c): blood sugar over a 3-month period

26. FSH and LH: gonadal abnormalities • GH: secretion of growth hormone • PTH: evaluates parathyroid gland function • TSH, T3, and T4: evaluate thyroid function • Rapid ACTH stimulation test: integrity of the adrenal glands • Serum aldosterone: levels of aldosterone

27. Imaging Studies • X-rays • CT and MRI • Nuclear medicine studies • Radioactive iodine uptake (RAIU) test: evaluates thyroid function • Radionuclide thyroid imaging: evaluates thyroid gland itself

28. Insight Only the Lonely