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Flashcards in Bone physiology Deck (69)
1

True or False
One vertebral fracture will lead to another

True

2

What do osteoclasts do?

Resorb bone

3

What do osteoblasts do?

Put down osteoid to form new bone

4

Who should be assessed using the risk factor assessment? (2)

Anyone over 50 with risk factors
Anyone under 50 with an early menopause or on steroids

5

When should a DEXA scan be requested?

10 year risk assessment of at least 10%

6

In a DEXA scan, which value is the most important?

T value

7

What does the T value have to be to be classified as osteoporosis?

More than -2.5

8

What is a Z score?

Age matched so compares with age and size

9

When are Z scores used?

If younger than 20

10

What class of drug is given if osteoporosis is diagnosed?

Bisphosphonate

11

What are examples of bisphosphonates?

Alendronic or risedronic acid

12

When is zolendronic acid given?

If DEXA intolerable

13

What is given in severe spinal osteoporosis?

Teriparatide

14

If osteopenia is diagnosed what is done?

Lifestyle advice e.g. smoking, alcohol, weight bearing exercise, falls advice
DEXA reassessment

15

True or False
Post-menopausal women should increase their dairy intake

True

16

How do bisphosphonates work?

Apoptosis of osteoclasts so inhibit bone resorption

17

What are long term potential side effects of bisphosphonates?

Osteonecrosis of jaw
Oesophageal Ca

18

How is zolendronic acid given?

Once yearly IV infusion

19

When is denosumab given?

If bisphosphonates intolerable.

20

How should alendeonic acid be given?

Tablet, 30 minutes before food and don't lie down for half an hour after

21

When should alendronic acid be stopped?

Oesophagitis or ulcers

22

What are common side effects of alendronic acid?

Abdo pain
Nausea
dyspepsia
GI side effects

23

How does denosomuab work?

Monoclonal Ab that binds to RANKL

24

What is RANKL?

Receptor activator of nuclear factor kB ligand

25

How does activating RANKL prevent osteoporosis?

Inhibits osteoclasts and decreases bone resorption

26

How is denosomuab given?

Subcut injection 6 monthly

27

Why is strontium not recommended as 1st line?

Fracture reduction is slightly less and dangerous in heart disease

28

Where does Paget's disease affect?

Long bones
Pelvis
Lumbar spine
Skull

29

What is Paget's disease?

Increased osteoclast activity with abnormalities. Reduced strength

30

What is a complication of Paget's disease?

Osteosarcoma

31

What symptoms may present with Paget's?

Often asymptomatic but bone pain or deformity and deafness

32

How is Paget's diagnosed?

XR
Increased alk phos

33

How is Paget's treated?

Bisphosphonates

34

Which defect causes osteogenesis imperfecta?

COL1A1/2
Autosomal dominant

35

What is associated with osteogenesis imperfecta?

Blue sclerae
Dentinogenesis imperfecta

36

Which receptor on the parathyroid is for calcium?

Ca sensitive receptor

37

What kind of receptor is CaSR?

G protein coupled

38

How is vitamin D stored in the liver?

Cholecaliferol

39

What does the liver convert it to?

25-hydroxycholecaliferol

40

What does the kidney turn it into?

1,25-hydroxycholecaliferol

41

What are symptoms of acute hypercalcaemia?

Thirst
Dehydration
Polyuria
Confusion

42

What are symptoms of chronic hypercalcaemia?

Myopathy
Fractures
Depression
Abdo pain

43

What are major causes of hypercalcaemia?

Primary hyperparathyroidism
Malignancy

44

What drugs can cause hypercalcaemia?

Vitamin D
thiazides

45

What will blood results be for 1o hyperparathyroidism?

Raised serum Ca
Raised serum PTH
Increased urine Ca excretion

46

What other serum protein is important for diagnosing malignancy?

Alkaline phosphate (raised in malignancy)

47

What is the treatment for acute hypercalcaemia?

Fluids
Loop diuretics once rehydrated
Bisphosphonates will lower Ca

48

How is 1o primary hyperparathyroidism managed?

Surgery or nothing

49

When should surgery for 1o hyperparathyroidism be indicated?

If end organ damage e.g. renal stones, osteoporosis, gastric ulcers or renal disease
Or if calcium is v high (>2.85)

50

What is 2o hyperparathryoidism?

Physiological response to low Ca
PTH raised

51

What is 3o hyperparathyroidism?

Overactive PTH after many years of 2o

52

Which genetic syndromes are closely linked with hyperparathyroidism?

MEN1/2

53

What is FHH?

Familial hypocalciuric hypocalcaemia

54

What signs will be present in FHH?

Low Ca urine
Hypercalcaemia

55

How does PTH work on the gut?

Causes it to absorb Ca and therefore increased serum Ca levels

56

In which fish is vitamin D high in?

Herring

57

What are the symptoms of hypocalcaemia?

Paraesthesia in extremities and perioral
tetany and cramps
Fatigue and myopathy
Long QT on ECG

58

What are the causes of hypocalcaemia?

Hypoparathyroidism
Vitamin D deficiency
renal failure
Pancreatitis

59

What is the treatment for acute hypocalcaemia?

10ml 10% IV calcium gluconate over 10 mins

60

In what congenital condition is the parathyroid gland underachieve?

DiGeorge syndrome

61

What are the other features of DiGeorge syndrome?

Cardiac abnormalities
Abnormal facies
Thymus aplasia
Cleft palate
Hypoparathyroidism/hypocalcaemia
Chromosome 22

62

What is the long term management of hypoparathyroidism?

Calcium supplement daily
Vitamin D tablet

63

Why can hypomagnaeseamia cause low calcium?

Ca release is Mg+ dependent

64

What causes hypomagnaeaemia ?

Alcohol
Thiazides
PPI

65

What is pseudohypoparathyroidism?

Genetic defect of GNAS1 which means that PTH is resisted

66

What are symptoms of pseudohypoparathyroidism?

Obesity
Learning disabilities
Brachdactyly of 4th metacarpal
Hypocalcaemia

67

What is pseudo-pseudohypoparathyroidism?

Same but with normal Ca

68

What can cause rickets?

Coeliac disease
Liver disease
Chronic renal failure

69

True or False
Alk phos is raised in Osteomalacia

True