ILA: OSTEOPOROSIS Flashcards
What is hydroxyapatite made of?
Calcium and phosphate
Name 4 cell types present in bone.
- Osteocyte
- Macrophage
- Osteoblast
- Osteoclast
Which cell type is involved in the resorption of bone during the remodelling process?
Osteoclast
Describe the changes to urinary calcium and phosphate levels due to the action of parathyroid hormone.
Urinary calcium decreases and urinary phosphate increases
What does decreased plasma calcium levels stimulate?
Secretion of parathyroid hormone
Which hormone increases the rate of synthesis of the active form of vitamin D (1,25-dihydroxycholecalciferol) in the kidneys?
Parathyroid hormone
What term describes defective mineralisation of bone matrix in an adult?
Osteomalacia
Which term describes a reduction in bone mass (greater than 2.5 standard deviations below the mean value for a young adult of the same sex) with normal mineralisation?
Osteoporosis
FRAX considers various risk factors in generating the 10-year probability of major osteoporotic fracture. Which of the following risk factors is not in the model?
- Family history of parental hip fracture
- Diagnosis of rheumatoid arthritis
- Regular exercise
- Current use of glucocorticosteroids
- Current smoking status
Regular exercise
Describe the blood test results for the bone profile in osteoporosis.
- Normal calcium
- Normal phosphate
- Normal Alk Phos
- Normal PTH
Describe the blood test results for the bone profile in osteomalacia.
- Decreased calcium
- Decreased phosphate
- Increased Alk Phos
- Increased PTH
Describe the blood test results for the bone profile in Paget’s disease.
- Normal calcium
- Normal phosphate
- Increased Alk Phos
- Normal PTH
What is the role of UV light in vitamin D metabolism?
Converts 7-dehydrocholesterol to cholecalciferol
Where is 1,25-dihydroxyvitamin D formed?
Kidney
Name 4 late complications following bone fractures.
- Avascular necrosis
- Myositis ossificans
- Pressure sores
- Non-union
