Physiology Flashcards
1
Q
3 molecules that regulate calcium in the blood
A
- PTH
- Calcitonin
- Vit D (synthesised in kidneys)
2
Q
Vit D synthesis steps
A
- 7-dehydrocholesterol converted to D3 with UV
- Liver = D3 –> 25HD
- Kidney = converted to calcitriol
- Calcitriol stimulated intestinal epithelial cells to increase calbindin-D proteins
3
Q
how does PTH raise blood calcium levels
A
- Increase bone resorption by binding to osteoblasts to express RANKL = increases osteoclasts
- Increase renal reabsoprtion Ca
- Increasws synthesis of calcitriol
4
Q
Calcitonin and calcium regulation
A
- Ca rises above normal range = stim thyroid gland to secrete calcitonin
- Decreases calcium levels by ingibiting osteoclasts
