1. Endocrinology Prof. K. Sivapalan

2. Jan. 2014Endocrine- general.2 Communication Between Cells Nervous. Humeral –Metabolites. –Paracrine. –Endocrine.

3. Jan. 2014Endocrine- general.3 Definition. Endocrine: –Gland that secretes hormones. Hormone: –Secreted into blood and act on distant target organs- insuilin, thyroxine, etc. Conventional endocrine glands are pancreas, thyroid, parathyroid, pituitary, adrenal and gonads. Liver, heart, lymphnodes and many other organs are now known to secrete substances with distant activity.

4. Jan. 2014Endocrine- general.4 Functions of Endocrine System Maintaining the internal environment. Respond to emergency demands. Integration of growth and development. Reproduction. One function- several hormones. One hormone- several functions.

5. Jan. 2014Endocrine- general.5 Neuro - Endocrine Integration. Neurons with endocrine function- –hypothalamus, posterior pituitary. Neural control of endocrine function- –Parathyroid gland. –Pancreas. Combined action of nervous system and endocrine system- –Maintenance of blood pressure.

6. Jan. 2014Endocrine- general.6 Regulation of Endocrine Secretion. Change in circulating metabolite. Change in tropic hormone. Nervous control.

7. Jan. 2014Endocrine- general.7 Feed Back Regulation. metabolite. Secretion of hormone. Response. Negative feed back. + - + Positive Feed Back +

8. Jan. 2014Endocrine- general.8 Transport of Hormones Water soluble hormones are dissolved in plasma. –Peptide hormones and catecholamines. Fat soluible hormones are bound to proteins. –Steroids. Thyroxine both ways.

9. Jan. 2014Endocrine- general.9 Blood Level of Hormones. Increased by secretion. Decreased by, –Metabolic destruction by tissues. –Binding with receptors in tissues. –Excretion by liver. –Excretion by kidneys.

10. Jan. 2014Endocrine- general.10 Mechanism of Action of Hormones. Binding with specific receptors in trget cells. The receptor brings about several changes in the activity of the cell Location of Receptors- –Cell membrane- for proteins, peptides and catecholamines. –Cytoplasm- for steroids. –Nucleus- thyroid hormones. Down regulation and up regulation of receptor numbers are also ways of feed back regulation.