1. 19 Nov. 2014Endocrine-System.ppt1 Endocrine Systems “Raging Hormones!”

2. 19 Nov. 2014 Endocrine-System.ppt2 Human Endocrine System Odd organ system Compare to nervous sys., digestive sys. Endocrine glands usually not connected Considered a “system” because of functional similarity

3. 19 Nov. 2014 Endocrine-System.ppt3 Endocrine System Endocrine glands Masses of epithelial tissue Cells secrete into interstitial spaces, Secretions (hormones) diffuse into blood No ducts! Contrast to exocrine glands

4. 19 Nov. 2014 Endocrine-System.ppt4 Endocrine System “Hormone”  Chemical messenger secreted into blood and carried to “target cells” where it alters activity.  Parathyroid hormone (PTH) and calcitonin regulate blood Ca 2+ concentration

5. 19 Nov. 2014 Endocrine-System.ppt5 Endocrine System Other chemical messengers Paracrines Autocrines Neurotransmitters discussed in nervous system

6. 19 Nov. 2014 Endocrine-System.ppt6 Hormones 3-4 Chemical groups Steroids Biogenic amines Peptides Eicosanoids Mostly paracrines Leukotrienes Prostaglandins

7. 19 Nov. 2014 Endocrine-System.ppt7 Hormones Steroids Derivatives of cholesterol Four covalently- bonded rings Adrenal cortex Gonads

8. 19 Nov. 2014 Endocrine-System.ppt8 Hormones Biogenic amines Derivatives of tyrosine, an amino acid  Thyroid hormones Thyroxine (T 4 ) Triiodothyronine (T 3 )  Adrenal medulla Epinephrine Norepinephrine Usually neurotransmitter

9. 19 Nov. 2014 Endocrine-System.ppt9 Hormones Peptides “Chains” of amino acids 4 – 200+ amino acids Hypothalamus Pituitary (Ant. & Post.) Islets of Langerhans Parathyroid hormone Digestive system hormones

10. 19 Nov. 2014 Endocrine-System.ppt10 Mechanisms of Hormone Action Lipid-soluble steroids & thyroid hormones Diffuse through plasma membrane Forms “hormone-receptor complex” Enter nucleus H-R complex binds to chromosome to activate/inactivate gene(s)

11. 19 Nov. 2014 Endocrine-System.ppt11 Mechanisms of Hormone Action Peptides & water-soluble amines Hormone (1) binds to receptor on cell surface Activates G- protein G- protein activates adenylate cyclase Converts ATP to cAMP cAMP activates protein kinases, which produce final effect.

12. 19 Nov. 2014 Endocrine-System.ppt12 Hormone Action One hormone may have multiple actions Epinephrine binds to α and β receptors “Fight-or-flight” syndrome Activate glycogenolysis Dilate arteries to skeletal muscles Constrict arteries to viscera

13. 19 Nov. 2014 Endocrine-System.ppt13 Hormone Action Regulation of growth and maturation in insects PTTH stimulates prothoracic gland to release ecdysone; Ecdysone stimulates formation of new cuticle and molting.

14. 19 Nov. 2014 Endocrine-System.ppt14 Hormone Action Regulation of growth and maturation in insects Juvenile hormone (JH) maintains larval development (inhibits maturation); JH secretion declines in older larva  pupa  adult

15. 19 Nov. 2014 Endocrine-System.ppt15 Human Endocrine System Odd organ system Endocrine glands usually not connected More glands and hormones than we can discuss here.