Biochemistry

Question 1

What is a quantitative bone disorder?

Answer 1

A disorder where the bone present is of good quality, however it is lacking in quantity.

Question 2

What is a qualitative bone disorder?

Answer 2

A disorder of the bone where there is sufficient quantity of bone present, however it is not of the required quality.

Question 3

An example of a quantitative disorder?

Answer 3

Osteoporosis

Question 4

What is osteoporosis?

Answer 4

A condition characterised by bone of a decreased density and increased porosity. Defined as a bone mineral density that is greater than 2.5 standard deviations below the mean peak of a young adult (of same race and gender).

Question 5

What is osteopenia?

Answer 5

An intermediate stage in which the bone mineral density is between 1-2.5 deviations below the normal value.

Question 6

First line treatment for osteoporosis?

Answer 6

Biphosphonates - these are first line and are used to reduce osteoclastic function. An example is alendronic acid.

Question 7

2nd line treatment for osteoporosis?

Answer 7

Desunomab - a monoclonal antibody that also reduces osteoclastic activity.

Question 8

What are osteoblasts and osteoclasts?

Answer 8

Osteoclasts are cells that are responsible for breaking down old bone (responsible for bone reabsorption).
Osteoblasts are cells that are responsible for rebuilding new bone in replacement of the old bone.

Question 9

Example of a qualitative bone disorder?

Answer 9

Osteomalacia is an example of a qualitative effect, it produces abnormal bone softening due to deficiencies in the mineralisation of osteoid (bone is immature). There will always be inadequate amounts of calcium and phosphates.