Calcium balance

Question 1

Rachitis (rickets)

Answer 1

Malformation (weakness) of bones caused by the lack of vitamin-D that leads to a decreased absorption of calcium from the gut during development.

Question 2

Osteoporosis

Answer 2

Weakening of the bones due to a loss of minerals (Calcium) and organic components.

Question 3

Osteoblast

Answer 3

Bone forming progenitor cell.

Question 4

Osteoclast

Answer 4

Phagocyte digesting bone tissue allowing remodelling of bone.

Question 5

Osteoid tissue

Answer 5

Organic part of the bone matrix made up by fibers and other components, its mineralization finishes bone formation.

Question 6

Remodelling

Answer 6

The continuous degradation and rebuilding of the bone tissue.

Question 7

Calcification

Answer 7

(Mineralization) osteoid tissue becomes bone tissue by the “drizzle” of calcium salts.

Question 8

Mineralization

Answer 8

(calcification) Osteoid tissue becomes bone tissue by the precipitation of calcium salts.

Question 9

Ergocalciferol

Answer 9

Vitamin D2, precursor of calcitriol, a dietary supplement found in certain fish oils and fungi.

Question 10

Cholecalciferol

Answer 10

Vitamin D3 (hormone), precursor of calcitriol, synthesised in the skin upon UV radiation.

Question 11

Calcitriol

Answer 11

Hormone prepared from D2 and D3; increases calcium absorption in the gut and calcium mobilization in the bone, thus increases calcium level in the blood.

Question 12

Pararthormon

Answer 12

Hormone of the pararhyroid glands; increases calcium reabsorption in the kidneys and calcium mobilization in the bone, thus increases calcium level in the blood.

Question 13

Calcitonin

Answer 13

Hormone produced by C cells in the thyroid gland: Inhibits osteoclast activity, thus decreases calcium level in the blood.