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Hypothalamus PowerPoint Presentation
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Hypothalamus

Hypothalamus

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Hypothalamus

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  1. Sleep Stress Exercise Limbic structures Metabolic signals Glucocorticoids Hypothalamus (-) GHIH (-) GHRH (+) Pituitary (-) GH somatotropin Indirect effects Somatomedins:IGF-1  protein synthesis  tissue growth Direct effects mobilize fat insulin antagonist

  2. Thyroid Hormones • Include • Triiodothyronine or T3 • Tetraiodothyronine or T4 or thyroxine • Transported in blood • Bind with intracellular receptor molecules and initiate new protein synthesis • Increase rate of glucose, fat, protein metabolism in many tissues thus increasing body temperature • Normal growth of many tissues dependent on

  3. Hypothyroidism Decreased metabolic rate Weight gain, reduced appetite Dry and cold skin Weak, flabby skeletal muscles, sluggish Myxedema Apathetic, somnolent Coarse hair, rough dry skin Decreased iodide uptake Possible goiter Hyperthyroidism Increased metabolic rate Weight loss, increased appetite Warm flushed skin Weak muscles that exhibit tremors Exophthalmos Hyperactivity, insomnia Soft smooth hair and skin Increased iodide uptake Almost always develops goiter Thyroid Hormone Hyposecretion and Hypersecretion

  4. Parathyroid Glands • Embedded in thyroid • Secrete PTH • Increases blood calcium levels • Stimulates osteoclasts • Promotes calcium reabsorption by kidneys

  5. Regulation of PTH Secretion

  6. Decreasing blood Calcium Parathyroids Parathyroid hormone . Kidneys Bone Active Vitamin D Reabsorption of Calcium Dissolution of CaPO4 crystals Small Intestine Increased blood Calcium Increased Calcium absorption in

  7. Adrenal Glands • Functions as part of sympathetic nervous system • Composed of medulla and cortex (3 layers) • Hormones • Medulla secretes epinephrine and norepinephrine • Cortex secretes mineralocorticoids, glucocorticoids, androgens

  8. Hormones of Adrenal Cortex • Mineralocorticoids • Zona glomerulosa • Aldosterone produced in greatest amounts • Increases rate of sodium reabsorption by kidneys increasing sodium blood levels (regulates water volume) • Glucocorticoids • Zona fasciculata • Cortisol is major hormone • Increases fat and protein breakdown, increases glucose synthesis, decreases inflammatory response • Androgens • Zona reticularis • Converted to androgen and testosterone

  9. Reabsorption of Na+ Excretion of K+ & H+  Blood Volume  Blood Pressure  Chloride Ion (-) (+) Kidney (-) Renin Lungs . Vasoconstriction  Blood Pressure Angiotensin II Zona Glomerulosa (+)  K+ Aldosterone

  10. Higher Brain Centers Hypothalamus Anterior Pituitary Zona Fasciculata (+) Nonspecific Stress (-) CRH (-) ACTH Cortisol Gluconeogenesis Mobilization of fat stores  bone formation  immune system

  11. Pancreas • Located along small intestine and stomach • Exocrine gland • Produces pancreatic digestive juices • Endocrine gland • Consists of pancreatic islets • Composed of • Alpha cells secrete glucagon • Beta cells secrete insulin • Delta cells secrete somatostatin

  12. Insulin Target tissues: liver, adipose tissue, muscle, and satiety center of hypothalamus Increases uptake of glucose and amino acids by cells Glucagon Target tissue is liver Causes breakdown of glycogen and fats for energy Insulin and Glucagon

  13. Regulation of Insulin Secretion

  14. Regulation of Blood Nutrient Levels After a Meal

  15. Regulation of Blood Nutrient Levels During Exercise

  16. Male: Testes Testosterone Regulates production of sperm cells and development and maintenance of male reproductive organs and secondary sex characteristics Inhibin Inhibits FSH secretion Female: Ovaries Estrogen and Progesterone Uterine and mammary gland development and function, external genitalia structure, secondary sex characteristics, menstrual cycle Inhibin Inhibits FSH secretion Relaxin Increases flexibility of symphysis pubis Hormones of the Reproductive System

  17. Pineal Body • In epithalamus • Produces • Melatonin • Enhances sleep • Arginine vasotocin • Regulates function of reproductive system in some animals

  18. Effects of Aging on Endocrine System • Gradual decrease in secretory activity of some glands • GH as people age • Melatonin • Thyroid hormones • Kidneys secrete less renin • Familial tendency to develop type II diabetes

  19. Diabetes Mellitus • Results from inadequate secretion of insulin or inability of tissues to respond to insulin • Types • Type I or IDDM (Insulin-dependent) • Develops in young people • Type II or NIDDM (Non-insulin dependent) • Develops in people older than 40-45 • More common