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Endocrinology. Prof. K. Sivapalan. Communication Between Cells. Nervous. Humeral Metabolites. Paracrine. Endocrine. Definition. Endocrine: Gland that secretes hormones. Hormone: Secreted into blood and act on distant target organs- insuilin , thyroxine , etc.
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Endocrinology Prof. K. Sivapalan
Communication Between Cells • Nervous. • Humeral • Metabolites. • Paracrine. • Endocrine. Endocrine- general.
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. Endocrine- general.
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. Endocrine- general.
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. Endocrine- general.
Regulation of Endocrine Secretion. • Change in circulating metabolite. • Change in tropic hormone. • Nervous control. Endocrine- general.
Feed Back Regulation. - Secretion of hormone. + Positive Feed Back Negative feed back. metabolite. + + Response. Endocrine- general.
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. Endocrine- general.
Blood Level of Hormones. • Increased by secretion. • Decreased by, • Metabolic destruction by tissues. • Binding with receptors in tissues. • Excretion by liver. • Excretion by kidneys. Endocrine- general.
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. Endocrine- general.
Learn About Each Hormone, • Source. • Latent period and Half life . • Regulation of secretion and removal • Mechanism of action • Physiological actions. • Consequences of excess and insufficiency. • Function tests and assessment. Endocrine- general.