Endocrine Physiology 6

1. Through which mechanism do osteoblasts regulate osteoclast formation?

RANKL-RANK & M-CSFOPG mechanism

2. In osteoporosis, which bone cells are defective?

Osteoclasts

3. Post-menopausal bone loss is due to oestrogen deficiency. What is the role of oestrogen in bone formation?

Oestrogen inhibits secretion of cytokines-IL-1, IL-6, TNF alpha which foster development of osteoclasts

4. What are the derivatives of vitamin D3 ?

Secosteroids

5. The formation  of family of proteins is helped by 1,25 dihydrocholecalciferol. Name the protein.

Calbindin-D

6. Vitamin D deficiency in children causes defective calcification of bone, what is this disease?

Rickets

7. Name a disease in adults that is similar to rickets.

Osteomalacia

8. Name the parathyroid cells secreting parathyroid hormone PTH.

Chief cells

9. PTH is a polypeptide, how many amino-acid molecules are present in PTH?

84

10. What is the normal plasma level of  PTH?

10 – 55 pg/mL

11. What is the action of PTH on bone?

Resorption

12. What is excessively present in urine when there is excess PTH?

Phosphate

13. What is parathyroid hormone related protein (PTHrP)?

A protein with PTH activity

14. How many amino acids are present in PTHrP?

140

15. Name the protein that stimulates cartilage when PTHrP is released in utero.

Indian hedgehog

 

16. What is excessively secreted in humoral hypercalcaemia of malignancy?

PTHrP

17. Name a calcium lowering hormone in plasma

Calcitonin

18. How many amino acids are present in calcitonin?

32

19. What is the half-life of growth hormone in humans?

6 – 20 min

20. Name the intermediary factor that brings about the action of growth hormone

Somatomedin

 ( UMS, 2008 )