Endocrine system


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Endocrine system

  1. 1. Endocrine system Glands and Hormones
  2. 2. Functions <ul><li>Control rates of chemical reactions </li></ul><ul><li>Aid transport of substances through membranes </li></ul><ul><li>Regulate water and electrolyte balances </li></ul><ul><li>Control reproductive processes </li></ul><ul><li>Control development and growth </li></ul>
  3. 3. Hormone <ul><li>Only affect target cells </li></ul><ul><ul><li>Have receptors </li></ul></ul><ul><li>Work in low concentrations </li></ul><ul><li>Proteins, glycoproteins or steroids </li></ul>
  4. 4. Prostaglandin <ul><li>Similar to hormones, but only lipids </li></ul><ul><li>Not stored, synthesized as needed </li></ul><ul><li>Stimulate smooth muscle or glands </li></ul><ul><li>Regulate fluids </li></ul><ul><li>Affect male and female reproductive physiology </li></ul><ul><li>Act locally </li></ul>
  5. 5. Control of endocrine glands <ul><li>Nervous system </li></ul><ul><li>Negative feedback </li></ul>
  6. 6. Pituitary – the master gland controls several other glands inferior to cerebral lobes in center of skull <ul><li>Anterior – made in pituitary </li></ul><ul><ul><li>Growth Hormone – stimulates body cells to grow </li></ul></ul><ul><ul><ul><li>Dwarfism – too little </li></ul></ul></ul><ul><ul><ul><li>Gigantism – too much </li></ul></ul></ul><ul><ul><li>Prolactin – milk production in new moms </li></ul></ul><ul><ul><li>Thyroid stimulating hormone – controls thyroid </li></ul></ul><ul><ul><li>Adrenocorticotropic hormone – controls secretion of hormones from cortex of adrenals </li></ul></ul>
  7. 7. Anterior Pituitary cont. <ul><ul><li>Follicle stimulating hormone – maturation of ova, production of sperm </li></ul></ul><ul><ul><li>Leutinizing hormone – ovulation, promotes secretion of sex hormones </li></ul></ul><ul><li>Posterior Pituitary – made in hypothalamus </li></ul><ul><ul><li>Antidiuretic hormone – reduces kidney excretion </li></ul></ul><ul><ul><li>Oxytocin – causes contractions in uterus and mammary glands </li></ul></ul>
  8. 8. Hypothalamus <ul><li>In brain just superior to pituitary </li></ul><ul><li>Made of modified nervous tissue </li></ul><ul><li>Secretes hormones that are stored in posterior pituitary </li></ul><ul><li>Stimulates pituitary </li></ul>
  9. 9. Thyroid <ul><li>Below larynx, surrounding trachea, butterfly shape </li></ul><ul><li>Secretes several hormones </li></ul><ul><ul><li>Thyroxine – regulates metabolism, development of nervous system, contains iodine </li></ul></ul><ul><ul><ul><li>Hypothyroid – too little – causes cretinism in children, slow metabolism in adults, treatable with drugs </li></ul></ul></ul>
  10. 10. Thyroid cont. <ul><ul><li>Hyperthyroid – too much thyroxine, overactive metabolism, treated with radioactive iodine or surgery </li></ul></ul><ul><ul><li>Goiter – enlarged thyroid caused by lack of iodine in the diet </li></ul></ul><ul><li>Calcitonin – moves calcium from blood to bones </li></ul>
  11. 11. Parathyroid <ul><li>4 small glands embedded in the posterior surface of the thyroid </li></ul><ul><li>Parathormone – moves calcium from bones to blood, also decreases blood phosphate </li></ul>
  12. 12. Adrenals <ul><li>On superior surface of kidneys; 2 parts </li></ul><ul><li>Medulla – inner portion made of modified nervous tissue </li></ul><ul><ul><li>Epinephrine/adrenaline – fear response </li></ul></ul><ul><ul><li>Norepinephrine/noradrenaline – anger response </li></ul></ul><ul><ul><li>Both of these increase heart rate, breathing, blood pressure and decrease digestive sys. “fight or flight” </li></ul></ul>
  13. 13. Adrenals cont. <ul><li>Cortex – outer portion </li></ul><ul><ul><li>Androgens – male sex hormones which may be converted to estrogens </li></ul></ul><ul><ul><ul><li>Source of testosterone in females, estrogen in males </li></ul></ul></ul><ul><ul><li>30 other different steroids with various functions </li></ul></ul>
  14. 14. Pancreas <ul><li>Located posterior to stomach </li></ul><ul><li>Has exocrine as well as endocrine function </li></ul><ul><ul><li>Islets of Langerhans are endocrine portion </li></ul></ul><ul><li>Glucagon – stimulates liver to convert glycogen to glucose, raises blood sugar </li></ul><ul><li>Insulin – stimulates liver and muscles to take in glucose, lowers blood sugar </li></ul>
  15. 15. Diabetes – 2 types <ul><li>Type I – Islets are destroyed by immune system, insulin must be injected </li></ul><ul><li>Type II – insulin resistance, body does not respond normally to insulin, can be controlled with diet and oral medication, often associated with obesity </li></ul>
  16. 16. Pineal <ul><li>Located deep in between the cerebral lobes of the brain </li></ul><ul><li>Melatonin – controls wake/sleep cycle in response to light; may also control longer cycles such as menstrual cycle </li></ul><ul><li>Light deprivation in winter may lead to seasonal affective disorder which includes depression </li></ul>
  17. 17. Thymus <ul><li>Located on superior surface of the heart </li></ul><ul><li>Thymosin – controls production and maturation of lymphocytes (immune system T-cells) </li></ul><ul><li>Reaches maximum size during puberty, then shrinks making elderly people more susceptible to disease </li></ul>
  18. 18. Reproductive glands <ul><li>Ovaries – estrogen, progesterone – egg production, breast development, deeper voice at puberty </li></ul><ul><li>Placenta – gonadotropin – suppresses menstrual cycle </li></ul><ul><li>Testes – testosterone – larger muscles, deep voice, facial and body hair </li></ul>
  19. 19. Digestive <ul><li>Linings of stomach and small intestine produce hormones </li></ul><ul><ul><li>Gastrin – affects acid producing glands of stomach </li></ul></ul>