4. 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 form 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

Osteoclast

Answer 3

phagocyte digesting bone tissue allowing remodeling of bones.

Question 4

Osteocyte

Answer 4

bone cell - osteoblasts are transformed into osteocytes; they are located in small cavities within the bone tissue and keep contact with each other thorugh cytoplasmic processes.

Question 5

Osteid tissue

Answer 5

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

Question 6

remodeling

Answer 6

the continous degredation and rebuilding of the bone tissue.

Question 7

calcification

Answer 7

(mineralization) osteoid tissue becomes bone tissue by the precipitation of calcium salts

Question 8

ergocalciferol

Answer 8

vitamin D2, precuros of cacitriol, a dietary supplement found in certatin fish oils and fungi.

Question 9

cholecalciferol

Answer 9

vitamin D3 (hormone), precursor of calcitriol, synthesized in the skin upon UV irradiation

Question 10

Calcitriol

Answer 10

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

Question 11

Parathormon

Answer 11

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

Question 12

calcitonin

Answer 12

hormone produced by C cells in the thyroid gland; inhibits osteoclast activity, thus decreases calcium level in the blood.