Minerals - Calcium

Question 1

What can Imbalances of Ca Lead to?

Answer 1

hypercalcaemia and hypocalcaemia

Question 2

Serum Calcium Levels are Controlled by Hormones, what do they do?

Answer 2

influence the release of stored calcium in bone

Question 3

Describe Parathyroid Hormone and give Role

Answer 3

secreted by parathyroid glands
short half life
rapid response

Increases RANKL
decreases OPG
= osteoclastgenesis

= increases serum Ca

Question 4

Describe Calcitonin and give Role

Answer 4

produced by parafollicular cells in thyroid

antagonises PTH effects
inhibits osteoclastgenesis

= decreases serum Ca

Question 5

Describe Calcitrol and give Role

Answer 5

1,25-Dihydroxy Vitamin D3

• produced by PTH in kidney
  = increases calcium absorption

Question 6

Describe Calcitrol and give Role

Answer 6

1,25-Dihydroxy Vitamin D3

• produced by PTH in kidney
  = increases calcium absorption

Question 7

steps of increasing calcium absorption

Answer 7

• low serum calcium
• parathyroid gland
• PTH
• kidney
• activate 1-hydroxylase
• 25-hydroxyvitamin D3 converts into 1,25-hydroxyvitamin D3

Question 8

Describe Osteocalcin

Answer 8

produced by osteoclasts and odontoblasts
- binds hydroxyapatite and calcium

Question 9

is Vitamin D3 hydrophilic or hydrophobic?

Answer 9

hydrophobic

Question 10

what group is vit d3 part of, what can it do?

Answer 10

steroid hormone group

• can directly affect gene expression by binding to steroid receptors