Thyroid, Pancreas, Parathyroid - Guyton Ch. 76, 78, 79 ...

3,917 views

Published on

Published in: Health & Medicine
1 Comment
6 Likes
Statistics
Notes
  • very good presentation
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
No Downloads
Views
Total views
3,917
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
324
Comments
1
Likes
6
Embeds 0
No embeds

No notes for slide

Thyroid, Pancreas, Parathyroid - Guyton Ch. 76, 78, 79 ...

  1. 1. Microscopic Appearance of the Thyroid Gland Figure 76-1; Guyton & Hall
  2. 2. Thyroid Hormone Synthesis & Secretion Figure 76-2; Guyton & Hall
  3. 3. Binding of Thyroid Hormones & Precursors to Thyroglobulin during Hormone Synthesis 3,3’,5’-Triiodothyronine (RT3) 3,5-Diiodotyrosine (DIT) 3,5,3’-Triiodothyronine (T3) O HO I I C H NH 2 COOH C H H I I O HO I I C H NH 2 COOH C H H I O HO I I C H NH 2 COOH C H H I C H NH 2 COOH C H H HO I C H NH 2 COOH C H H HO I C H NH 2 COOH C H H I HO Tyrosine 3-Monoiodotyrosine (MIT) Thyroxine (T 4 ) Thyroglobulin Molecule
  4. 4. Actions of Thyroid Hormones Figure 76-5; Guyton & Hall
  5. 5. Metabolic Effects of Thyroid Hormones Parameter ↓ T 3 , T 4 ↑ T 3 , T 4 Basal metabolic rate ↓ ↑ Carbohydrate metabolism ↓ Gluconeogenesis ↑ Gluconeogenesis ↓ Glycogenolysis ↑ Glycogenolysis Normal serum [glucose] Normal serum [glucose] Protein metabolism ↓ Synthesis ↑ Synthesis ↓ Proteolysis ↑ Proteolysis Muscle wasting Lipid metabolism ↓ Lipogenesis ↑ Lipogenesis ↓ Lipolysis ↑ Lipolysis ↑ Serum [cholesterol] ↓ Serum [cholesterol] Thermogenesis ↓ ↑ Table 48-1, Boron & Boulpaep
  6. 6. Hypothalamohypophyseal-Thyroid Axis Hypothalamus Thyrotrope Thyroid T 3 , T 4 TRH TSH _ _ + +
  7. 7. Pathophysiology of Thyroid Hormones <ul><li>Graves’ disease – autoimmune disorder; immune complex mimics TSH – stimulates continual production of thyroid hormone – leads to hyperthyroidism and goiter formation. </li></ul><ul><li>Cretinism – deficiency of thyroid hormones in childhood – results in severe growth retardation and mental retardation. </li></ul>
  8. 9. Hypothalamohypophyseal-Thyroid Axis in Graves’ Disease Hypothalamus Thyrotrope Thyroid T 3 , T 4 TRH TSH _ + _ + TSI +
  9. 10. Histology of an Islet of Langerhans of the Pancreas Figure 78-1; Guyton & Hall
  10. 11. Metabolic Effects of Glucagon Stimulate Inhibit Glucose Free fatty acids Ketoacids Amino acids     Glucose Amino acids Free fatty acids Liver Adipose tissue Ketoacids Glycogen Glucose-P Pyruvate Plasma Berne & Levy, Figure 47-19
  11. 12. Approximate Rates of Insulin & Glucagon Secretion at Different Blood Glucose Levels 40 80 120 160 200 240 Plasma glucose (mg/dl) 100% 50% 0 100% 50% 0 Insulin Response ( ) Glucagon Response ( )
  12. 13. Anatomy of the Parathyroid Glands & Microscopic Appearance of Chief Cells Figure 79-9; Guyton & Hall
  13. 14. <ul><li>Bone </li></ul><ul><ul><li> resorption (  osteoclasts) </li></ul></ul><ul><ul><li> osteocytic osteolysis </li></ul></ul><ul><li>Kidney </li></ul><ul><ul><li> Ca 2+ reabsorption </li></ul></ul><ul><ul><li> phosphate reabsorption </li></ul></ul><ul><ul><li> Na + reabsorption (weak effect) </li></ul></ul><ul><ul><li> 1,25-(OH) 2 -D 3 </li></ul></ul><ul><li>Intestine </li></ul><ul><ul><li> Ca 2+ absorption </li></ul></ul><ul><ul><li> phosphate absorption </li></ul></ul>PTH Actions
  14. 15. 0 6 8 10 12 14 50 100 PTH secretion (% maximal rate) Total plasma [Ca 2+ ] (mg/dL) Plasma Calcium Concentration & PTH Secretion
  15. 16. Hypocalcemia Disorder Plasma [PTH] Plasma [1,25-(OH) 2 -D 3 ] Urine Bone Plasma [Ca 2+ ] Plasma [Phosphate] Vitamin D deficiency Chronic renal failure (2°) * * Osteomalacia * Primary events or disturbances Surgical hypoparathyroidism (2°) * Osteomalacia Resorption Castanzo, Table 9-17 Phosphate cAMP Phosphate (  GFR ) * Resorption Resorption cAMP Phosphate
  16. 17. Primary Hyperparathyroidism Plasma[PTH] * Plasma [1,25-(OH) 2 -D 3 ] Urine Phosphate Ca 2+ cAMP Bone Resorption Plasma [Ca 2+ ] Plasma [Phosphate] * Primary disturbance Castanzo, Table 9-17

×