1. The Glands of the Endocrine System

2. Endocrine Glands Hypothalamus Pituitary –Anterior –Posterior Thyroid Gland Parathyroid glands Adrenal Glands –Cortex –Medulla Pancreas –Islets of Langerhans Gonads –Ovaries or –Testes Pineal gland Thymus

3. Hypothalamus Part of brain –Regulates ANS, sex drive, hunger, thirst, body temperature, etc. –Hormones related to these functions “Releasing hormones” Axonal transport to posterior lobe

4. Anterior Pituitary –TSH (thryoid stimulating hormone) –ACTH (adrenocorticotropic hormone) –FSH (gonadotropin) –LH (gonadotropin) –GH (growth hormone) –Prolactin-releasing hormone

5. Anterior Pituitary Imbalances Growth hormone (GH or hGH) –Promotes mitosis, cell division –Elongation of long bones, etc. –Healing of wounds, lack of hGH slows growth –Hypersecretion in childhood results in giantism –Hyposecretion in childhood results in dwarfism –Hypersecretion in adult produces acromegaly

6. Pituitary—Posterior lobe Oxytocin –Stimulates smooth muscle contraction of uterus & mammary glands, feels of attachment. ADH –Stimulates water reabsorption in collecting ducts. –Stimulates vasoconstriction (vasopressin) –Lack  diabetes insipidus

7. Posterior Pituitary Imbalances ADH –Hyposecretion produces diabetes –Excessive thirst and urination Diabetes Insipidus Foundation, Inc.

8. Thyroid Gland Located in neck Composed of follicles that produce: Thyroxin (T 4 ) Triiodothyronine (T 3 ) –Both “thyroid hormones”, are the body’s major metabolic hormone Parafollicular cells produce: Calcitonin –Decreases blood Ca 2+ by depositing it in bones

9. Thyroid imbalances Hypothyroidism results in: –Edema –Goiter - low levels of iodine –Cretinism Hyperthyroidism results in: –Graves disease

10. Parathyroid Glands Four small glands embedded in posterior of thyroid –Parathyroid hormone (PTH) –Stimulates osteoclasts to release Ca 2+ from bone –Stimulates Ca 2+ uptake from intestine & kidney

11. Parathyroid Imbalances Severe hyperparathyroidism causes massive bone destruction If blood Ca 2+ fall too low, neurons become overactive, resulting in tetany

12. Adrenal Glands Located on top of each kidney Cortex –Corticosteroids Medulla Epinephrine Norepinephrine

13. Adrenal Cortex Cortex –Mineral corticoids Aldosterone  regulate salt and water balance –Glucocorticoids Cortisol  regulate glucose metabolism and the immune system. –Gonadocorticoids Androgens Estrogens

14. Adrenal Cortex Imbalances Hypersecretion leads to Cushing’s disease Hyposecretion leads to Addison’s Disease

15. Adrenal Medulla Medulla –The adrenal medulla mediates short–term responses. –Cells are modified neurons (lack axons) Epinephrine (adrenaline) Norepinephrine (noreadrenaline) –enable a rapid ( fight-or- flight ) response to stress by increasing blood glucose and blood pressure and directing blood to the heart, brain and skeletal muscles.

16. Pancreas Consists of two major types of secretory tissues which reflects its dual function –Exocrine gland secretes digestive juice localized in the acinar cells –Endocrine gland releases hormones localized in the islet cells (islets of Langerhans)

17. Pancreatic Islets Approximately a million within the pancreas Control centers for blood glucose –Insulin from beta cells –Glucagon from alpha cells

18. Pancreas Imbalances Diabetes Mellitus

19. Gonads Ovaries –Estrogen –Progesterone Testes –Testosterone Reproductive functions when we study reproductive system.

20. Pineal gland Melatonin –Day/night cycles Timing of sleep, body temperature, appetite Secretion of melatonin begins with darkness –Participates in setting the body’s clock Melatonin is a potent antioxidant Melatonin is high when young and is reduced as we age

21. Thymus Thymopoietins, thymic factor, thymosins –Influence development of T lymphocytes

22. Non-Endocrine Gland Hormones Stomach (gastrin) Small intestine (duodenum  intestinal gastrin, secretin, cholecystokinin ) Heart ( atrial natriuretic peptide ) Kidneys ( erythropoietin, active vitamin D3 ) Adipose tissue ( leptid, resistin, estrogen- like prostaglandins ) Placenta ( human chorionic gonadotropin (hCG), human placental lactogen, relaxin )

23. Functions regulated by the Endocrine System Growth & Development Healing Water balance Blood Pressure Calcium Metabolism Energy Metabolism Stress Responses Secondary Sex Characteristics

24. Growth Hormones Growth hormone-releasing hormone Human growth hormone (hGH) Thyrotropin (TSH) Thyroxine & triiodothyronine Calcitonin Somatostatin (GHIH)

25. Healing Hormones Growth hormone-releasing hormone Human growth hormone (hGH) Thyrotropin (TSH) Thyroxine & triiodothyronine Calcitonin Glucagon, Insulin Erythropoietin

26. Water Balance & Blood Pressure Hormones ADH Aldosterone Angiotensin II Atrial natriuretic Hormone Epinephrine

27. Calcium Metabolism Hormones Calcitonin Parathyroid Hormone (PTH) Estrogens/androgens Growth hormone

28. Energy Metabolism Hormones Thyroxine & triiodothyronine Thyroid-stimulating H. (thyrotropin, TSH) Epinephrine & norepinephrine Insulin Glucagon Adrenocorticotropic Hormone (ACTH) Cortisol

29. Stress Hormones Epinephrine & norepinephrine T 4 &T 3 ACTH Cortisol