Brainscape's Knowledge GenomeTM

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


See full index

MSK final > Cartilage and Articular Joint Lubrication -Rega > Flashcards

Cartilage and Articular Joint Lubrication -Rega Flashcards

1
Q

What are some differences in bone vs cartilage (collagen type, make up, O2 requirement, covering)

A

bone:

  • Type I collagen
  • osteocytes embedded in collagen/inorganic matrix
  • moderate O2 requirement
  • vascularized
  • covered with periosteum

cartilage:

  • type II collagen
  • chondrocytes embedded in collagen/proteoglycan matrix
  • low O2 requirement
  • anti-vascular, anti-clotting
  • covered in perichondrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are some functional properties of cartilage? What do these functional properties rely on?

A
  • stiffness
  • durability
  • distribution of load

rely on the extracellular matrix!!!

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

What composes 60-80% of the wet weight of cartilage?

A

tissue fluid (water with dissolved gases, small proteins and metabolites)

-structural macromolecules (proteoglycans and glycoproteins) only make up 20-40% of the weight

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

What secretes the extracellular matrix (ground substance) of cartilage?

A

chondrocytes

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

What structure of cartilage allows for its resistance of compression?

A

the glucosamine side units of proteoglycan repel each other and attract water and contribute to the stiffness of the cartilage

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

What structures of the body are composed of fibrocartilage?

A
  • Glenoid labrum
  • Acetabular labrum
  • Articular discs (ie clavical)
  • Lining of groove for tendons (ie biceps, etc.)
  • Medial and lateral knee menesci
  • Annulus fibrosis of IVD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What addition to the matrix in Elastic cartilage gives it an increased resistance? What is made of elastic cartilage?

A

elastin gives it resistance

  • external ear
  • corniculate cartilages of the hyoid
  • epiglottis
  • apices of arytenoids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What body parts are made of hyaline cartilage?

A
  • costal
  • nasal
  • tracheal and bronchial and most laryngeal
  • articular cartilage
  • temporary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

*What are some characteristics of articular cartilage?

A

-NO perichondrium

  • 4 regions, orientation of collagen fibrils (from joint space–> bone):
    1. tangential, parallel to the surface
    2. intermediate=45 degrees to surface
    3. radial, radial arrangement
    4. calcified
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

*What are the differences in the zones of articular cartilage?

A
  1. tangential, parallel to the surface: resist high tensile load, fine densely packed collagen fibers, secrete proteins involved in surface lubrication
  2. intermediate=45 degrees to surface, right angles to each other: contains large amounts of water, MOST deformation under load
  3. radial, radial arrangement: fibers continue into calcified zone, many insert on subchondral bone for anchor
  4. calcified: matrix with calcium salts, anchors cartilage to bone, 3 and 4 separated by “tidemark” and increase age causes tidemark toward the surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What region of articular cartilage contains the most water? What region undergoes the most deformation under load?

A

both are region 2==> intermediate region

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

What region of articular cartilage resists tensile/shear forces the best? Why?

A

Zone 1–> tangential

because it has the most densely packed collagen fibers

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

How/where will failure of collagen occur?

A
  • failure: cracks propagate perpendicular to load

- maximum deformation and failure typically start in the tangential zone

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

What are the functions of articular cartilage?

A
  • Distribute skeletal load
  • Provide a friction-reducing, weight-bearing surface.
  • Lubricate joint surface
  • Absorb impact and minimize peak stresses on subchondral bone
  • Increase joint congruence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the stiffness in compression of articular cartilage arise from?

A
  1. water association

2. inherent stiffness of proteoglycan

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

How does articular cartilage receive nutrients?

A

through synovial fluid

  • movement and loading are critical for nutrients because there is no vascularization in articular cartilage
  • -> water wash is essential=pushing water out of the proteoglycans when loading and movement occur
17
Q

How is lubrication of a synovial joint achieved?

A
  • lubrication=binding of cartilage proteoglycans + water
  • passive shear forces on cartilage prompt the chondrocyte cells in it to produce proteoglycan 4, which is secreted into synovial fluid–> lubrication
18
Q

What are the components of synovial fluid? Synovial membrane?

A

plasma filtrate (electrolytes + small molecules; fewer proteins)

synovial membrane:

  • macrophage like cells that phagocytize debris
  • cells secreting synovial proteins –> create viscosity (hyaluronic acid and lubricin)
19
Q

How does articular cartilage initially behave under loading?

How does this change with increased duration of loading?

When would it be best to perform high impact activities?

A

initially stiff under loading.

With increased duration of loading, viscous flow increases deformation and relieves stress on the water–> decreased ability to absorb impact

high-impact activity is best performed in mornings

20
Q

What are the 3 different types of lubrication?

A
  1. Boundary lubrication (non-moving joint): fluid clings by chemical attraction of lubricant to cartilage surface
  2. sliding hydrodynamic lubrication (moving): synovial fluid sucked into space (due to deformation and physical property of viscosity)
  3. squeeze film hydrodynamic lubrication (movement and impact loading): fluid forced out into joint space under load and sucked back in when unloaded

faster joint motion=lower viscosity

21
Q

What types of things can result in cartilage destruction? (6)

A
  • inhibition of nutrient flow (continuous compression, pannus adhesion in rheumatoid disease, synovial adhesion in prolonged immobilization)
  • “Wear & tear” – repetitive microtrauma
  • Repetitive intra-articular hydrocortozone injections
  • Traumatic acute tears
  • Crystal formation
  • Septic destruction – pus is chondrolytic
22
Q

What are 4 pathological reactions of cartilage?

A
  • Increase/decrease in general/local growth [in juveniles]
  • Destruction (crystals–> inflammation)
  • Degeneration
  • Peripheral proliferation – osteophytes at tiny marginal area of articular cartilage covered by perichondrium (osteophyses as a result of vascularization of subchondral marrow–> endochondral ossification)
23
Q

How do intervertebral discs change from juvenile to adult?

A
  • Juvenile vascularized from segmental arteries supplying adjacent bone
  • Adult loss of vascularization & relative O2 concentration
  • Nucleus pulposus of adult lumbar disc hypoxic
  • Accounts for lack of success in injecting chondrocytes into nucleus pulposis

MSK final (21 decks)

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