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Vertebral Column > Cartilage > Flashcards

Flashcards in Cartilage Deck (66)
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1
Q

What cells are present in the cartilage connective tissues?

A

Fibroblasts
Adipose cells
Osteocytes
Chondrocytes

2
Q

What is present in the ECM of cartilage?

A

Fibres (collagen, reticular or elastic)
Ground substance (GAGs and glycoproteins)
Tissue fluid

3
Q

What is the reference for the general constituents of cartilage?

A

Kerr, 2010

4
Q

What is cartilage surrounded by? What is its structure?

A

Perichondrium:

  • Dense, irregular connective tissue
  • Composed largely of collagen
5
Q

What are the general functions of cartilage?

A

Supportive framework of organs
Articulate surfaces
Forms most of foetal skeleton (largely replaced by bone)

6
Q

What cells form cartilage and what is it surrounded by?

A

Chondrocytes surrounded by specialised ECM

7
Q

What is the outer layer of perichondrium and what is it composed of?

A

Fibrous outer layer composed of:

  • Fibroblasts
  • Collagen fibres
8
Q

What is the inner layer of perichondrium and what is it composed of?

A

Chondrogenic inner layer:

  • Chondroblasts
  • Chondrogenic cells (produce new chondroblasts)
9
Q

What is the reference for general cartilage structure, perichondrium and chondrocytes?

A

Gartner and Hiatt, 2014

10
Q

What is the space that individual chondrocytes are found within?

A

A lacuna

11
Q

What is an isogenous group?

A

When a chondrocytes divides there may be more than one chondrocytes within the lacuna

12
Q

What is the typical shape of a chondrocyte?

A

Egg-shaped

13
Q

What is the function of chondrocytes?

A

Produce and maintain ECM

14
Q

How much of cartilage is made up of ECM?

A

> 95%

15
Q

What are the predominant components of the cartilage ECM?

A

Type II collagen

Proteoglycan aggregates

16
Q

How does the high degree of hydration of the cartilage ECM affect its function?

A

It means cartilage can respond to varying loads

17
Q

How is nutrition supplied to the ECM?

A

Diffusion between blood vessels in:

  • Perichondrium
  • Chondrocytes
18
Q

What is the matrix immediately surrounding a chondrocyte?

A

Capsular matrix

19
Q

What is the territorial matrix?

A

Darker matrix immediately around lacunae of isogenous groups

20
Q

What is the lighter ECM that composes the rest of the ECM?

A

Interterritorial matrix

21
Q

What are the references for the ECM?

A

Ross and Pawlina, 2006

Kerr, 2010

22
Q

How do chondrocytes develop?

A

Mesenchymal embryonic cells differentiate into chondroblasts
Chondroblasts secrete cartilage matrix
Matrix surrounds Chondroblasts = Chondrocytes in lacunae

23
Q

Describe interstitial cartilage growth?

A

Growth from a number of centres
Chondroblasts multiply and divide into clusters of cells = Isogenous groups
Groups produce ECM which separates Chondroblasts = Chondrocytes

24
Q

In what type of cartilage does interstitial growth occur?

A

Immature

25
Q

What is appositional cartilage growth?

A

Growth through addition of new layers to existing ones

Occurs in chondrogenic layer of perichondrium

26
Q

In what type of cartilage does appositional growth occur?

A

Mature cartilage

27
Q

What is the reference for cartilage growth?

A

Gartner and Hiatt, 2014

28
Q

What are the components of hyaline cartilage?

A

Chondrocytes
ECM:
- Predominantly Type II collagen
- Chondroitin sulfate

29
Q

What are the functions of hyaline cartilage?

A

Low friction surface via lubrication of synovial joints

Distributes forces to underlying bone

30
Q

Where is hyaline cartilage found?

A

Articulate surfaces of synovial joints
Foetal skeleton - Provides model for its development
Costal cartilage - Some passive movement

31
Q

What are the components of fibrocartilage?

A
Chondrocytes
ECM:
- Type I collagen fibrils (connective tissue matrix)
- Type II collagen fibrils (hyaline)
Dense regular connective tissue
32
Q

Why is there less matrix associated with chondrocytes in fibrocartilage?

A

Chondrocytes are dispersed amongst collagen fibres

33
Q

Does fibrocartilage have a perichondrium?

A

No

34
Q

What shape is the nucleus of chondrocytes in fibrocartilage?

A

Rounded

35
Q

What is the shape of the nucleus of fibroblasts in fibrocartilage?

A

Flattened and elongated

36
Q

What are the functions of fibrocartilage?

A

Shock-absorption
Flexibility
Deformation resistance

37
Q

Where is fibrocartilage found?

A

Secondary cartilaginous joints (symphyses):

  • IV discs
  • Pubic symphysis
38
Q

What is a useful reference for both hyaline cartilage and fibrocartilage?

A

Ross and Pawlina, 2006

39
Q

What are the components of elastic cartilage?

A
Chondrocytes
ECM:
- Type II collagen
- Proteoglycans
- Elastin (elastic fibres and interconnecting elastic sheets)
40
Q

Which types of cartilage calcify with age?

A

Hyaline

41
Q

Where is elastic cartilage found?

A

Pinna

Pharyngotympanic (eustachian) tube

42
Q

What cartilages are present in the vertebral column?

A
Hyaline:
- Zygapophyseal joints
- Cartilagenous end plates
Fibrocartilage:
- IV discs
43
Q

What directions do the facet joints in the cervical, thoracic and lumbar regions allow movement in?

A
Cervical:
 - All directions
Thoracic:
- Lateral Flexion
- Rotation
Lumbar:
- Flexion
- Extension
- Lateral flexion
44
Q

What is the role of hyaline cartilage on the facet joints?

A

Reduces friction

45
Q

In what direction does the thickness of the IV discs increase?

A

Craniocaudally

46
Q

What is the composition of the IV discs?

A

Mostly ECM

Only ~1% volume chondrocytes

47
Q

IV discs are the largest non-vascular structures in the body. How much distance is there between some lumbar discs and direct blood supply?

A

20mm

48
Q

What types of collagen does the nucleus pulposus produce?

A

Type II

49
Q

What types of collagen does the annulus fibrosus produce?

A

Type I

Type II

50
Q

What are the functions of the IV discs?

A

Shock absorption
Flexibility
Transmission of load

51
Q

From what do the cartilaginous endplates develop from?

A

Mesoderm

52
Q

How much of the IV space do the cartilaginous end plates make up?

A

~5% of adult IV space

~50% at birth

53
Q

At birth there are vascular channels running through end plates, how do these change throughout life and how does this affect function?

A

Fill with ECM by end of first decade of life

Provide nutrition to IV disc

54
Q

What are the functions of the cartilaginous end plates?

A

Growth plate for vertebrae in early life
Nutrient transport to IV disc
Barrier between VB and nucleus pulposus preventing Schmorl’s nodes

55
Q

What can arise if the IV discs degenerate?

A

Intervertebral osteochondrosis

56
Q

How does intervertebral osteochondrosis initially begin?

A

As a Schmorl’s node:

- Herniation of nucleus pulposus through cartilaginous and bony endplates into adjacent vertebral body

57
Q

Where is intervertebral osteochondrosis most common?

A

Cervical region

Lower lumbar region

58
Q

How does intervertebral osteochondrosis appear radiographically?

A

Loss of disc space

Bony sclerosis of vertebral bodies

59
Q

If intervertebral osteochondrosis progresses, what can it result in?

A

Destruction of cartilaginous endplate

Bulging of outer fibres of annulus fibrosus

60
Q

What is osteoarthritis?

A

A non-infective arthritis affecting synovial joints

Degeneration of articulate cartilage through reduced proteoglycan content in ECM

61
Q

What are the pathological features of osteoarthritis?

A

Loss of joint space
Osteophyte growth at joint margins
Subchondral sclerosis
(Subchondral cysts)

62
Q

What is the only synovial joint in the spine affected by osteoarthritis?

A

Zygapophyseal joints

63
Q

What is the sequelae of uncovertebral joint degeneration in the cervical spine?

A

Osteophyte formation
Stenosis of IV foramina
Vertebral artery compression

64
Q

What are the costal articulations with the spine?

A

Costovertebral

Costotransverse

65
Q

Where is degeneration in the thoracic spine common?

A

Between T11 and T12 with ribs 11 and 12 respectively

66
Q

What happens in SIJ degeneration?

A

Complete or partial joint ankylosis:
- Stiffening and hardening of joint
- Stiffness and reduced range of movement of joint
Osteophytes on anterior articular surface
Bony sclerosis on anterior articular surface