Endocrine ii online

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Endocrine ii online

  1. 1. Copyright © 2011 Pearson Education, Inc. ORGANS OF THE ENDOCRINE SYSTEM Pituitary gland Thyroid gland Parathyroid gland Adrenal gland Pineal gland Pancreas Gonads
  2. 2. Copyright © 2011 Pearson Education, Inc. The Pituitary Gland • “Hypophysis” = master gland / pituitary gland • Pea sized gland • In hypophyseal fossa of sphenoid • Connect to hypothalmus via infundimulum • Secretes several hormones
  3. 3. Copyright © 2011 Pearson Education, Inc. The Pituitary Gland • Two lobes: 1. Posterior pituitary (lobe): • Composed of nervous tissue • Connected to hypothalmus 1. Anterior pituitary (lobe) (adenohypophysis) • Glandular tissue Anterior lobe Posterior lobe
  4. 4. Copyright © 2011 Pearson Education, Inc. Posterior Lobe • Posterior lobe • A downgrowth of hypothalums • Hypothalums = emotional center
  5. 5. Copyright © 2011 Pearson Education, Inc. Posterior Lobe - Hormones • Produced by hypothalamus…released by posterior lobe • Oxytocin • Stimulates contractions in childbirth • Causes release of breast milk • Antidiuretic hormone (ADH) • Causes kidneys to reabsorb water
  6. 6. Copyright © 2011 Pearson Education, Inc. Anterior Lobe • Controlled by hypothalmus • Secretes several hormones into blood stream
  7. 7. Copyright © 2011 Pearson Education, Inc. Anterior Pituitary Hormones 1. Growth hormone (GH) 2. Thyroid-stimulating hormone (TSH) or thyrotropin 3. Adrenocorticotropic hormone (ACTH) 4. Follicle-stimulating hormone (FSH) 5. Luteinizing hormone (LH) 6. Prolactin (PRL) • Know names and abbreviations
  8. 8. Copyright © 2011 Pearson Education, Inc. Anterior Pituitary Hormones • All are proteins (water soluble) • Use cAMP to cause changes in cell • TSH, ACTH, FSH, and LH are all tropic hormones • Tropic hormones regulate other endocrine glands
  9. 9. Copyright © 2011 Pearson Education, Inc. Growth Hormone (GH) • Targets bone and skeletal muscle • Helps increase body mass • Promotes protein synthesis • encourages fat use
  10. 10. Copyright © 2011 Pearson Education, Inc. Imbalances of Growth Hormone • Hypersecretion • In children results in gigantism • In adults results in acromegaly • Hyposecretion • In children results in pituitary dwarfism gigantism acromegaly
  11. 11. Copyright © 2011 Pearson Education, Inc. • Stimulates the activity of the thyroid • Negative feedback controls production Thyroid-Stimulating Hormone (Thyrotropin)
  12. 12. Copyright © 2011 Pearson Education, Inc. Adrenocorticotropic Hormone (Corticotropin) (ACTH) • Stimulates the adrenal gland to release corticosteroids • Such as epinephrine • External factors alter release • fever, hypoglycemia, and stressors
  13. 13. Copyright © 2011 Pearson Education, Inc. Gonadotropins • Regulate gamete production in gonads 1. Follicle-stimulating hormone (FSH) 2. Luteinizing hormone (LH) • FSH stimulates gamete (egg or sperm) production • LH promotes production of gonadal hormones • Present after onset of puberty
  14. 14. Copyright © 2011 Pearson Education, Inc. Prolactin (PRL) • Stimulates milk production • Blood levels rise toward the end of pregnancy • Suckling stimulates PRH release and promotes continued milk production
  15. 15. Copyright © 2011 Pearson Education, Inc. THYROID GLAND Metabolism control •Thyroid hormone •Calcitonin
  16. 16. Copyright © 2011 Pearson Education, Inc. Thyroid Gland • Located in the throat inferior to Adam’s apple • produces thyroid hormone • To make thyroid hormone you need iodine • thyroglobulin + iodine = thyroid hormone
  17. 17. Copyright © 2011 Pearson Education, Inc. Thyroid Hormone • Major metabolic hormone • Increases metabolic rate and heat production • Plays a role in: • Maintenance of blood pressure • Regulation of tissue growth • Development of skeletal and nervous systems • Reproductive capabilities
  18. 18. Copyright © 2011 Pearson Education, Inc. Synthesis and Regulation of Thyroid Hormone • Cells require iodine to synthesize TH • Regulated by negative feedback • TH inhibits TSH production
  19. 19. Copyright © 2011 Pearson Education, Inc. Homeostatic Imbalances of TH • Hyposecretion in adults — goiter formation • Enlarged thyroid • Caused by lack of iodine • Iodine fortified salt • Hypersecretion — Graves’ disease • Antibodies mimic TSH • Too much TH produced • Protruding eyes.
  20. 20. Copyright © 2011 Pearson Education, Inc. Figure 15.10 goiter
  21. 21. Copyright © 2011 Pearson Education, Inc. Calcitonin • Also produced by thyroid • Lowers blood calcium (Ca2+ ) • Inhibits osteoclasts • Causes calcium absorption  into urine • Production triggered by high blood Ca2+
  22. 22. Copyright © 2011 Pearson Education, Inc. PARATHYROID GLANDS
  23. 23. Copyright © 2011 Pearson Education, Inc. Parathyroid Glands • tiny glands embedded in posterior thyroid • Secrete parathyroid hormone (PTH) • PTH — important in Ca2+ levels
  24. 24. Copyright © 2011 Pearson Education, Inc. Parathyroid Hormone (PTH) • Functions opposite to calcitonin • Produced when low blood Ca2+ levels • Stimulates osteoclasts • digest bone  release Ca2+ • Kidneys resorb Ca2+ • Negative feedback regulation: • rising Ca2+ inhibits PTH release
  25. 25. Copyright © 2011 Pearson Education, Inc. ADRENAL GLANDS
  26. 26. Copyright © 2011 Pearson Education, Inc. Adrenal Glands • Location: suprarenal = above the kidneys • Two main regions • Adrenal cortex — glandular tissue • secrete corticosteroids • Adrenal medulla — nervous tissue • Sympathetic nervous system • Secrete epinephrine
  27. 27. Copyright © 2011 Pearson Education, Inc. Corticosteriods • Three types produced: 1. Mineralocorticoids – Aldosterone 2. Glucocorticoids – cortisol / cortisone 3. Gonadocorticoids – sex hormones
  28. 28. Copyright © 2011 Pearson Education, Inc. Mineralocorticoids • Regulate electrolytes (primarily Na+ and K+ ) • blood volume, blood pressure • Aldosterone potent mineralocorticoid • Na+ reabsorption / water retention by kidneys Glucocorticoids • Cortisone and cortisol • Helps resist stressors • Helps regulates blood sugar
  29. 29. Copyright © 2011 Pearson Education, Inc. Imbalances of Glucocorticoids • Hypersecretion —Cushing’s syndrome • Depresses the immune system • Promotes changes in cardiovascular, neural, and GI function • Preparing for stress • weight gain • Hyposecretion — Addison’s disease • Weight loss, severe dehydration, and hypotension
  30. 30. Copyright © 2011 Pearson Education, Inc. Gonadocorticoids • Sex hormones = androgens (male sex hormones) • In tissues converted to testosterone or estrogens in females • Contribute to: • Onset of puberty • Secondary sex characteristics
  31. 31. Copyright © 2011 Pearson Education, Inc. Adrenal Medulla • Secretes epinephrine and norepinephrine • hormones cause “fight or flight” • Blood diverted to brain, heart, and skeletal muscle • glucose levels rise • Blood vessels constrict • heart beats faster
  32. 32. Copyright © 2011 Pearson Education, Inc. PINEAL GLAND AND PANCREASE
  33. 33. Copyright © 2011 Pearson Education, Inc. Pineal Gland • Small gland hangs from roof of third ventricle • Secretes melatonin…derived from serotonin • Melatonin affects • sexual maturation • Day/night cycles • body temperature, sleep, appetite
  34. 34. Copyright © 2011 Pearson Education, Inc. Pancreas • Has exocrine and endocrine cells • Produce pancreatic juice for digestion (exocrine) • Produce hormones (endocrine) • Regulate blood sugar • α cells produce glucagon • when “glucose is gone” • β cells produce insulin • When blood glucose is high
  35. 35. Copyright © 2011 Pearson Education, Inc. Glucagon / Insulin • Glucagon targets liver: • Gluconeogenesis — produces glucose from glycogen stores • Releases glucoses into blood • Insulin targets tissues • Causes uptake of glucose into cells
  36. 36. Copyright © 2011 Pearson Education, Inc. Figure 15.18 Liver Liver Tissue cells Stimulates glucose uptake by cells Stimulates glycogen formationPancreas Pancreas Insulin Blood glucose falls to normal range. Stimulates glycogen breakdown Blood glucose rises to normal range. Glucagon Stimulus Blood glucose level Stimulus Blood glucose level GlycogenGlucose GlycogenGlucose Glucagon / Insulin
  37. 37. Copyright © 2011 Pearson Education, Inc. Diabetes Mellitus • Low insulin signaling • Low levels of production or low activity of insulin • Symptoms • Polyuria —huge urine output • Polydipsia —excessive thirst • Polyphagia —excessive hunger • Hyperinsulinism: • Too much insulin; hypoglycemia, can cause unconsciousness
  38. 38. Copyright © 2011 Pearson Education, Inc. GONADS Ovaries, placenta and testes
  39. 39. Copyright © 2011 Pearson Education, Inc. Ovaries and Placenta • Ovaries produce estrogens and progesterone: • Maturation of female reproductive organs • Female secondary sexual characteristics • Breast development and mensturation • Placenta secretes estrogens, progesterone, and human chorionic gonadotropin (hCG) • Pregnancy tests look for hCG
  40. 40. Copyright © 2011 Pearson Education, Inc. Testes • Produce testosterone • Maturation of male reproductive organs • Male secondary sexual characteristics • Needed for sperm production
  41. 41. Copyright © 2011 Pearson Education, Inc. Other Organs Produce Hormones • Kidneys • Erythropoietin  red blood cell production • Adipose tissue • Leptin  appetite control • Thymus • Lymph cell development • Heart • Blood pressure and volume • GI cells • Stimulate digestion

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