Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

LCRS 2 > Metabolic Bone Disease – Histopathology > Flashcards

Metabolic Bone Disease – Histopathology Flashcards

1
Q

What are the 4 main functions of bones?

A

Mechanical – support and site for muscle attachment
Protective
Metabolic – reserve of calcium
Structural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two main components of bone and what are their relative proportions?

A

Inorganic (65%) – calcium hydroxyapatite (store of 99% of the body’s calcium, 85% of the phosphorous and 65% of Na and Mg)
Organic (35%) – bone cells and protein matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the classification of bone as cortical and cancellous.

A 
Cortical  
 Long bones 
 80% of skeleton 
 Appendicular skeleton 
80-90% calcified 
 Mainly mechanical and protective role 
Cancellous 
 Vertebrae and pelvis  
 20% of skeleton  
 Axial  
15-25% calcified  
 Mainly metabolic 
 Large surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the indications for bone biopsy?

A 
Evaluate bone pain or tenderness 
Investigate abnormality seen on X-ray  
For bone tumour diagnosis  
To determine the cause of unexplained infection  
To evaluate therapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two types of bone biopsy?

A

Closed – needle – core biopsy with Jamshidi needle

Open – for sclerotic or inaccessible lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the three types of bone cell?

A

Osteoblast – build bone by laying down osteoid
Osteoclast – multinucleate cells of the macrophage family that resorb bone
Osteocyte – osteoblast like cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where are osteocytes found?

A

Lacunae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What cytokine is important for stimulating the differentiation of osteoclast precursors into pre-osteoclasts?

A

M-CSF (this is produced by osteoblasts)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which cells produce RANKL and what is its effect?

A

Pre-osteoblasts

It stimulates the maturation of osteoclasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do mature osteoblasts produce that blocks the RANK/RANKL binding?

A

Osteoprotegrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are bones classified anatomically?

A

Flat
Long
Cuboid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What type of ossification leads to the formation of:

a. Long Bones
b. Flat Bones

A

a. Long bones
Endochondral ossification
b. Flat bones
Intramembranous ossification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How else can bone be classified?

A

Trabecular (cancellous) or compact (cortical)

Woven (immature) or lamellar (mature)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is metabolic bone disease?

A

Disordered bone turnover due to imbalance of various chemicals in the body (vitamins, hormones, minerals etc.)
Overall effect is reduced bone mass (osteopaenia) often resulting in fractures from little or no trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the primary causes of osteoporosis?

A

Age

Post-menopause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is osteomalacia and what can it be caused by?

A 
Condition of defective bone mineralisation that can be caused by: 
Vitamin D deficiency  
Phosphate deficiency (usually related to chronic renal disease)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the metabolic and endocrine consequences of vitamin D deficiency?

A

Secondary hyperparathyroidism –> increased bone resorption

Hypocalcaemia – neuronal excitability causing muscle twitching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the histology of osteomalacia.

A

No calcification of bone
More uncalcified osteoid
Bones are very bendy and cannot carry musculature very easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the clinical consequences of osteomalacia?

A

Bone pain/tenderness
Fracture (horizontal fractures at Looser’s zone at the neck of the femur are commonly seen)
Proximal weakness
Bone deformity

20
Q

What are the consequences of hyperparathyroidism?

A

Hypercalcaemia
Hypophosphataemia
Osteitis fibrosa cystica

21
Q

List the four organs that are directly or indirectly affected by parathyroid hormone to control calcium metabolism.

A

Parathyroid glands
Bones
Kidneys
Proximal small intestine

22
Q

State some causes of primary hyperparathyroidism.

A

Parathyroid adenoma

Chief cell hyperplasia

23
Q

State some causes of secondary hyperparathyroidism.

A

Chronic renal insufficiency

Vitamin D deficiency

24
Q

What are the symptoms of hyperparathyroidism?

A 
Stones, Bones, Abdominal Groans and Psychic Moans 
Stones – calcium oxalate renal stones  
Bones – osteitis fibrosa cystica  
Abdominal Groans – acute pancreatitis  
Psychic Moans – psychosis and depression
25
Q

What is the most important investigation for hyperparathyroidism and what will it show in someone with hyperparathyroidism?

A

X-ray of the hand
Subperiosteal bone erosions
Brown cell tumours – small areas of resorption in the long bones of the fingers that are filled with osteoclasts

26
Q

What are the five features of renal osteodystrophy?

A 
Increased bone resorption (osteitis fibrosa cystica)  
Osteomalacia  
Osteoporosis 
Osteosclerosis  
Growth retardation
27
Q

What are the consequences of renal osteodystrophy on phosphate and calcium levels?

A

Hyperphosphataemia as failure to excrete phosphate
Hypocalcaemia as a result of a decrease in vitamin D metabolism
Secondary hyperparathyroidism

28
Q

What is Paget’s disease?

A

Disorder of bone turnover (there is a lack of proper communication between the cells)

29
Q

What are the three stages of Paget’s disease?

A

Osteolytic - focal bone loss
Osteolytic-osteosclerotic- bone responds to the mass bone loss
Quiescent osteosclerotic- osteoblasts begins response to bone loss and is weakened disorganised bone structure

30
Q

Describe the histology of Paget’s disease.

A

Prominent reversal lines

Masses of osteoclasts in the same site as osteoblasts

31
Q

Which sites does Paget’s disease most commonly affect?

A

Skull

Spine

32
Q

What is a Haversian canal?

A

Channel that blood vessels run in within bone

33
Q

Pits in the bone surface where osteoclasts are found (also called resorption bays)

A

Howships lacunae

34
Q

Main internal structure of bone

A

Periosteum most superficial
Cortex deeper which is compact cortical bone
Medulla inside

35
Q

What is bone mainly in metaphysis

A

Trabecular

36
Q

Different types of bone anatomically

A

Flat- protective such as ribs skull
Long- mechanical such as femur
Short/cuboid- carpals which stabilise movement
Irregular- complex shapes to protect organs such as pelvis
Sesamoid- embedded in tendon

37
Q

Macroscopic division of bone

A

Cancellous

Cortical

38
Q

Microscopic classification of bone

A

Mature woven

Immature lamellar

39
Q

Micro anatomy of cortical bone

A

Lamellar organised in rod shaped osteons with central canal for vessels
Osteocytes dotted around with a dendritic network involved in signalling

40
Q

Multi nuclear bone cell

A

Osteoclast

41
Q

Standard bone biopsy site

A

Transiliac as site of all types of bone

42
Q

Most common bone disorders

A 
Osteoporosis 
Osteomalacia 
Primary hyperparathyroidism 
Renal osteodystrophy
Paget’s disease
43
Q

Define osteoporosis

A

Defined as bone density less than -2.5 on DEXA

44
Q

Osteomalacia in children

A

Rickets

45
Q

Signs of rickets

A

See bowing of bones and widen growth plates

LCRS 2 (44 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions