Brainscape's Knowledge GenomeTM

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


See full index

YR5 Histopathology > Crash course: Bone and Skin > Flashcards

Crash course: Bone and Skin Flashcards

1
Q

Describe the structure of bones

A

Head: Epiphysis
Neck: Metaphysis (contains growth plate- physis)
Shaft: Diaphysis

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

Describe the composition of bone

A

Outer: Cortical
Inner: Medullary cavity- site of RBC production

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

Describe the structure of a joint

A

Articular capsule

Each bone covered in cartilage to prevent rubbing

Synovial cavity containing synovial fluid to lubricate joints on movement

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

What triad of features characterises McCune Albright syndrome?

A

Cafe-au-lait spots
Precocious puberty
Fibrous dysplasia

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

What is the most common malignant bone cancer in adults?

A

Osteosarcoma

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

What are different classifications of fractures?

A

Complete or Incomplete

Closed (Simple): Clean break with intact soft tissue

Comminuted: Splintered bone with intact soft tissue

Compound: Fracture site communicates with skin surface

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

What are the stages of fracture repair?

A
  1. Formation of haematoma at fracture site (pro-callus)
  2. Deposition of new, immature bone, provides scaffolding (fibrocartilaginous callus)
  3. Mineralisation of immature bone (Important to have Vit D)
  4. Remodelling along weight-bearing lines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is osteoarthritis?

A

Degeneration of articular cartilage
Mechanical “wear + tear”
Remodelling of adjacent bone + inflammation

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

What is primary and secondary osteoarthritis?

A

Primary: Age related

Secondary: Any age, previously damaged or congenitally abnormal joint.

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

What are the 4 x-ray features of osteoarthritis?

A

Loss of joint space
Osteophytes
Subchondral sclerosis
Subchondral cysts

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

Where are common sites for osteoarthritis?

A

Vertebrae, HIPS + KNEES

DIPJ/ PIPJ of the hand

Carpometacarpal + metatarsophalangeal joints

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

Give 3 typical features of OA presentation

A

Pain following use, improves with rest

Unilateral Sx

No systemic upset

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

What is rheumatoid arthritis?

A

chronic, systemic AI disorder characterized by symmetrical synovitis (inflammation of synovium)

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

What is the epidemiology of RA?

A

F > M
Any age, peaks 30-40y

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

List 3 factors increasing genetic predisposition to RA

A

HLA DR4 + HLA DR1
PADI 2+4: increase citrullination of proteins
PTPN2 LoF: (usually suppresses T cell activation)

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

Describe the pathogenesis of RA (5)

A
  1. Rheumatoid factor + anti-CCP binds to receptors on synoviocytes
  2. Leads to T + B cell proliferation + angiogenesis
  3. Release of inflammatory markers
  4. Pannus formation
  5. Cartilage + bone destruction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Give 3 x-ray findings in RA

A

Joint subluxation
Soft tissue swelling
Erosions at joint margins

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

Proliferation of which cell occurs in RA?

A

Synoviocytes

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

Give 5 key histological features of RA

A

Synovitis

Proliferation of synoviocytes

Thickening of synovial membranes

Inflammatory cell infiltrates esp. T cells

Fibrin deposition- leads to scarring around joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are differentiating features between RhA and OA?

A

RhA:
Symmetrical

Small joints, hands + feet, sparing DIPJ

Wrists, elbows, ankles + knees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are 4 characteristic sites for rheumatoid arthritis?

A

Radial deviation of wrist

Ulnar deviation of fingers

‘Swan neck’ + ‘Boutonniere’ deformity of fingers

‘Z’ shaped thumb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Give 3 symptoms of RA

A

Early morning stiffness >30 mins (may improve with activity)

Fatigue

Systemic Sx: low fever, weight loss, malaise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is osteomyelitis?

A

Infection of bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 2 types of osteomyelitis?

A

Haematogenous: more common in kids
Non-haematogenous: more common in adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are common sites of osteomyelitis?

A

Adults:
Vertebrae
Jaw (2º to dental abscess)
Toe (2º to diabetic skin ulcer) (>3mm)

Children:
Long bones (usually metaphysis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which is the most common implicated organism in osteomyelitis?

A

Staphylococcus aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which is the most common organism implicated in osteomyelitis in sickle cell patients?

A

Salmonella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the imaging modality of choice for osteomyelitis?

A

MRI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Give risk factors for haematogenous and non haematogenous osteomyelitis?

A

H: SCA, IVDU, immunosuppression, HIV, infective endocarditis

NH: DM + foot ulcers, peripheral arterial disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which organism may be implicated in osteomyelitis in IVDU?

A

Pseudomonas aeruginosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is seen on x-ray if osteomyelitis goes untreated?

A

1w: Irregular sub-periosteal new bone formation (involucrum)

1-2w: Irregular lytic destruction (osteolysis)

3-6w: Detachment of necrotic cortex (sequestra)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the association between TB and osteomyelitis?

A

Rare cause of OM
More destructive + resistant to control.

Spinal disease (50%) may result in psoas abscess + severe skeletal deformity (Pott’s disease).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is gout?

A

rapid onset crystal-induced arthritis

Most common form of inflammatory arthritis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Which joint is typically affected in acute gout?

A

1st Metatarsalphalangeal joint of the great toe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What causes gout?

A

prolonged hyperuricaemia due to purine breakdown
Results in accumulation of monosodium urate (MSU) crystals in the joint.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Give 5 risk factors for gout

A

Alcohol
Obesity
Metabolic syndrome
African American origin
FH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the gold standard investigation for gout?

A

Synovial fluid aspiration (FNA)
Examination under polarised light

NEGATIVELY birefringent NEEDLE shaped crystals composed of monosodium urate

YELLOW when parallel to compensator ray

38
Q

What is seen on X-ray in gout?

A

Rat bite erosions

39
Q

What is the pathognomic lesion in gout?

A

Tophus

40
Q

What is pseudogout?

A

microcrystal synovitis caused by deposition of calcium pyrophosphate dihydrate crystals (CPPD) in synovium

41
Q

Which joints are most commonly affected in pseudogout?

A

Knees
Wrists
Shoulders

42
Q

What is seen on examination under polarised light in psuedogout?

A

RHOMBOID shaped POSITIVELY birefringent crystals
BLUE when parallel to compensator ray

43
Q

What is seen on X-ray in pseudogout?

A

White lines of chondrocalcinosis

(calcium deposition in joint space)

44
Q

Give 4 features of benign bone tumours

A

No periosteal reaction

Thick endosteal reaction

Regular bone formation

Intraosseous + regular calcification

45
Q

Give 5 features of malignant bone tumours

A

Acute periosteal reaction

Distinct border between normal + malignant bone

Irregular bone formation

Extraosseous + irregular calcifiation

Extremely PAINFUL

46
Q

Describe the epidemiology of osteosarcoma

A

Adolescence
V rare

47
Q

Which bone is commonly affected in osteosarcoma?

A

Knee (60%)
(Tibia + Femur)

48
Q

Give 3 histological features (buzzwords) for osteosarcoma

A

Malignant mesenchymal cells

ALP +ve

Replacement of BM with trabecular bone

49
Q

Give 3 features on X-ray in osteosarcoma

A

Elevated periosteum
Codman’s triangle
Sunburst appearance

50
Q

Describe the epidemiology of Chondrosarcoma

A

> 40s

51
Q

Which bones are commonly affected in Chondrosarcoma?

A

Axial skeleton
Femur
Tibia
Pelvis

52
Q

Give 3 histological features (buzzwords) for Chondrosarcoma

A

Malignant CHONDROCYTES
(proliferation of cartilage)

53
Q

Give 2 features on X-ray in Chondrosarcoma

A

Lytic lesion
Fluffy calcification

54
Q

Describe the epidemiology of Ewing’s sarcoma

A

<20y
HIGHLY MALIGNANT

55
Q

Which bones are commonly affected in Ewing’s sarcoma?

A

Long bones
Pelvis

56
Q

Give a histological feature (buzzword) for Ewing’s sarcoma

A

Sheets of small round cells

57
Q

Give a feature on X-ray in Ewing’s sarcoma

A

Onion skinning of periosteum

58
Q

Describe the epidemiology of giant cell (borderline malignancy)

A

20-40
F > M

59
Q

Which bone is commonly affected in giant cell? (borderline malignancy)

A

Knee- ephiphysis

60
Q

Give 3 histological features (buzzwords) for giant cell (borderline malignancy)

A

Osteoclasts + stromal cells

“SOAP BUBBLE appearance”

“GIANT MULTI-NUCLEATE OSTEOCLASTs”

61
Q

Give a feature on X-ray in giant cell (borderline malignancy)

A

Lytic/ lucent lesions right up to articular surface

62
Q

What is fibrous dysplasia?

A

Bone replaced by fibrous tissue

63
Q

What histological feature characterises fibrous dysplasia?

A

“Chinese letters”
+ Trabecular
Bone parenchyma infiltrated with fibrous tissue (bone not so dense)

64
Q

Give 2 features of fibrous dysplasia on X-ray

A

Soap bubble osteolysis

Shepherd’s crook deformity: bowing of metaphysis

65
Q

What are the layers of epidermis from superficial to deep?

A

Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale

(come lets get some beers)

66
Q

What are the 2 types of skin lesion?

A

Inflammatory: eczema + psoriasis, bullous disease

Cancer: BCC, SCC, Melanoma

67
Q

What are the 2 theories of aetiology of eczema?

A

Inside out: bodies own reaction to internal IgE (AI IgE sensitisation) leads to skin barrier dysfunction

Outside in: body reacts to external allergen exposure leading to IgE sensitisation

68
Q

What mutation causes eczema?

A

Mutations in filaggrin gene

69
Q

What are the 2 types of reaction driving eczema?

A

T1 hypersensitivity: classic- atopic dermatitis

T4 hypersensitivity: contact dermatitis e.g. jewellery, watches, occupational

70
Q

What are 4 histological features of eczema?

A

Thickening of epidermis

Spongiosis: fluid collection in dermis

Eosinophil infiltrate in dermis

Dilated dermal capillaries

71
Q

What is the pathophysiology of psoriasis?

A
  1. T4 T-cell hypersensitivity reaction within the epidermis
  2. T-cell recruitment + release of inflammatory cytokines e.g. TNF-a
  3. Keratinocyte hyperproliferation
  4. Epidermal thickening
72
Q

What inflammatory cell is involved in psoriasis? What does this cause?

A

MUNRO’s MICROABSCESSES form, from recruitment of neutrophils

73
Q

What buzzword is associated with psoriasis?

A

Parakeratosis
(abnormal retention of keratinocyte nuclei in stratum corneum)
(release of lots of keratin + proliferation of keratinocytes)

74
Q

What sign may be seen in psoriasis? What causes this?

A

Auspitz sign
Rubbing skin causes bleeding

75
Q

What is the most common type of psoriasis? Which sites are usually affected?

A

Chronic plaque psoriasis
Extensor surfaces

76
Q

List 5 types of psoriasis

A

Chronic plaque
Flexural
Guttate
Erthrodermic/ pustular
Koebner phenomenon

77
Q

Give 2 features of guttate psoriasis

A

“Rain drop” lesions on back + torso
2w after Group A Streptococcal infection

78
Q

Psoriasis is associated with what nail changes?

A

POSH
Pitting
Onycholysis
Subungual Hyperkeratosis

79
Q

Which form of psoriasis is an emergency?

A

Erythrodermic/ pustular

80
Q

What is Koebner phenomenon?

A

New skin lesions of a pre-existing dermatosis at sites of trauma in otherwise healthy skin

81
Q

Which population is affected by Bullous pemphigoid? Which areas?

A

Elderly population
Flexural surfaces

82
Q

Describe the pathophysiology of bullous pemphigoid

A
  1. IgG antibodies + C3 bind to hemidesmosomes (adhesion molecules) in BM of epidermis
  2. Epidermis lifts off
  3. Fluid accumulates in space a.k.a. sub-epidermal bulla
83
Q

Give 2 histological features of bullous pemphigoid

A

Eosinophilia
Linear deposition of IgG along basement membrane

84
Q

Compare the bulla in bullous pemphigoid and pemphigus vulgaris

A

BP: Strong, difficult to burst

PV: Weak, easily broken/ ruptured + ripped apart

85
Q

Describe onset of Pemphigus vulgaris

A

Blisters start in mouth before spreading to other parts of the body

86
Q

What is the pathophysiology of pemphigus vulgaris?

A

IgG to desmoglein 1 + 3 (adhesion molecules) between keratinocytes in stratum spinosum

Acantholysis aka intra-epidermal bulla

87
Q

Which population is affected by pemphigus follaceus?

A

Elderly

88
Q

What is the pathophysiology of Pemphigus follaceus?

A

IgG against desmoglein in stratum corneum

Detachment of superficial keratinocytes

89
Q

Describe the epidemiology of skin cancers

A

BCC: 70%
SCC: 20%
Melanoma: 10%

90
Q

What is the most important prognostic feature in melanomas?

A

Breslow thickness

91
Q

What is the most common melanoma?

A

Superficial spreading (90%)

YR5 Histopathology (27 decks)

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