The document summarizes the roles and mechanisms of parathyroid hormone and calcium regulation in the body. It discusses how parathyroid hormone regulates calcium levels through its effects on the kidneys, intestines, and negative feedback loops. It also covers causes of and treatments for conditions related to abnormal parathyroid hormone levels, including hypoparathyroidism, primary and secondary hyperparathyroidism, and the Chvostek sign seen in hypocalcemia.

1. Parathyroid hormone Dr. Sadaf Mumtaz 03/03/11

3. What is the role of Kidneys? Preventing reprecipation of Calcium freed from bones Enhance activation of Vit D What is the role of intestine?

4. Mechanism of action hPTH/PTHrP receptor PTH-2 CPTH Pseudohypoparathyroidism Adenylyl cyclase PLC

5. Negative feed back loops Calcitonin plays a role in skeletal integrity in pregnancy or breast feeding Gastrointestinal hormones

7. Causes of hypophosphatemia Respiratory alkalosis Alcohol abuse Malabsorption Phosphaturia Primary renal dysfunction Diuretics Hyperparathyroidism

9. Pathophysiology Hypoparathyroidism Osteocytes Osteoclasts Rx Primary Hyperparathyroidism Osteoclasts Osteoblast----alkaline phosphatase Effects of hypercalcemia Parathyroid poisoning and metastatic calcification Kidney stones

10. Secondary hyperparathyroidism Difference Vit D deficiency Chronic renal disease

11. Tapping the facial nerve at the angle of jaw in a patient with moderate hyposecretion of a particular hormone elicits a characteristic grimace on that side of the face. Which endocrine abnormality could give rise to this so called ‘Chvostek sign’ ?

12. Thanks