2. Histopathology and radiology Flashcards Preview

LCRS Y2: Musculoskeletal > 2. Histopathology and radiology > Flashcards

Flashcards in 2. Histopathology and radiology Deck (28)
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1

What are the 2 broad categorisations of mature bone?

Cortical
Cancellous

2

What % of bone is cortical and where is cortical bone most abundant?

80% of bone
Long bones

3

Describe the structure of cortical bone

Mature, lamellar bone - PARALLEL lamellae

4

Describe the structure of cancellous bone

Mature, lamellar bone - CONCENTRIC lamellae

5

What is the primary function of cancellous bone and where is it most abundant?

Metabolic fx - can dissolve/ resorb quickly for Ca++ homeostasis
Vertebrae and pelvis

6

Describe the process of mineralisation

Process through which an organic substance becomes impregnated by inorganic substances

7

What name is given to immature bone? Describe it structure

Woven bone
Irregularly-arranged collagen

8

What are the cannaliculae in bone?

Communication channels for osteocytes

9

What can be seen where there is osteoclast activity?

Howship's lacunae
= "bite-marks" where breakdown is occuring

10

Recall the relative proportions of organic and inorganic matter in bone, and summarise the composition of each of these

Organic (cells and protein matrix) = 35%
Inorganic (Ca hydroxyapatite) = 65%

11

What is the role of the RANK ligand in bone homeostasis?

When RANK combines with RANK-L osteoclasts are stimulated to differentiate

12

By what mechanism is osteoclast action inhibited?

Osteoprotegerin
Inhibitor of RANK:RANK-L binding

13

Where are osteocytes located in bone?

Lacunae

14

Distinguish between primary and secondary osteoperosis

Primary = age-related, post-menopause
Secondary = caused by drugs (eg thyroid drugs) or systemic disease

15

Recall the key distinguishing features of osteoperosis from other metabolic bone diseases

NORMAL mineralisation so serum biochemistry is normal - just a reduced mass of bone

16

What is raised ALP indicative of? Give 4 examples of where this might be seen

Increased bone turnover
1. Paget's
2. Osteomalacia
3. Bony Mets
4. HyperPTHism

17

Sumamrise the possible radiological findings in osteoperosis

MAY BE NORMAL
OR
1. Osteopaenic
2. Osteosclerotic

18

Why might osteoperosis demonstrate osteopaenia

Loss of bone quantity rather than quality

19

How does osteopaenia appear radiologically?

Reduced opacity

20

What is osteosclerosis?

Increased bone density

21

Recall 2 key features of osteomalacia radiologically

1. Looser's zone fractures (horizontal fracture in cortical bone)
2. Codfish vertebrae
(biconcave vertebrae)

22

Recall 2 radiological features of Paget's disease

1. Cortical thickening
2. Coarsening trabeculae

23

Describe how primary and secondary hyperPTHism can be distinguished radiologically?

Primary = bone resorption
Secondary = bone resorption AND INCREASED DENSITY
Bone resorption has appearance of erosion, and can lead to "brown tumour"

24

What is renal osteodystrophy?

Comprises all the skeletal changes of CKS - a combo of:
OsteoMALACIA
OsteoSCLEROSIS
OsteoPEROSIS
OsteoTITIS FIBROSIS CYSTICA

25

Describe the serum biochemistry of renal osteodystrophy (phosphate, calcium, PTH, pH)

HIGH phosphate
LOW calcium
HIGH PTH
Metabolic acidosis

26

How does sclerosis appear radiologically?

Rugged vertebrae (Jersey spine)

27

Recall 3 radiological features of renal osteodystrophy

Brown tumour
Jersey Spine
Soft tissue calcification around vessels

28

Recall 2 radiological features of Rickets

Cupped and frayed metaphysis due to increased stress
Widenened unmineralised growth plate