Collagen

Question 1

Collagen is the most abundant ? In the body

Answer 1

Protein

Question 2

Functions of articular cartilage

Answer 2

Distribute joint loads over a wide area

Allow relative movement of the opposing joint surfaces with minimal friction and wear

Question 3

Sections of articular cartilage

Answer 3

Superficial tangential
Middle
Deep
Tidemark

Question 4

Superficial tangential

Answer 4

Sheets of fine densely packed fibrils randomly woven parallel to surface

Question 5

Middle

Answer 5

Greater distances between randomly oriented and homogenously dispersed fibrils

Question 6

Deep fibers

Answer 6

Larger radially oriented bundles

Question 7

Tidemark

Answer 7

Interface between articular cartilage and calcified cartilage

Question 8

Tensile strength can range from

Answer 8

3-100MPa

Question 9

Stress strain curve contents

Answer 9

Toe region
Elastic region
Plastic region

Question 10

Toe region

Answer 10

Fibrils pull out and realign

Question 11

Populations of aggrecans

Answer 11

First
Second

Question 12

First aggrecan

Answer 12

Present throughout life
Rich in chondroitin sulfate

Question 13

Second aggrecan

Answer 13

Only present in adults
Rich in keratan sulfate

Question 14

Proteoglycan changes with maturation

Answer 14

Water, carb, pro ratio progressively decreases
Also KS and CS decrease
10:1 at birth
2:1 in adults

Question 15

Where is water most concentrated

Answer 15

Articular surface

Question 16

Donnan osmotic pressure theory

Answer 16

Swelling

Question 17

When water is compressed by a load

Answer 17

Water is forced out
Charge density increases
Increasing osmotic pressure
Increasing repulsive force

Question 18

PG in collages network enable _____

Answer 18

Compression resistance

Question 19

Porosity

Answer 19

Pore volume to total volume

Question 20

Interconnected pores allow ______

Answer 20

Permeability

Question 21

Cartilage has _____ porosity and _____ permeability

Answer 21

High porosity
Low permeability

Question 22

With deformation _____ shrink which ______ permeability

Answer 22

Pores, decrease

Question 23

Chondrocyte function

Answer 23

Generates stimuli to promote maintenance

Question 24

Compromised cartilage

Answer 24

Leads to abnormal stimuli
Abnormal remodelling
Debilitating function

Question 25

Degeneration means

Answer 25

Limited ability to repair

Question 26

Degeneration leads to failure related to

Answer 26

Magnitude of the stress Total number of stress peaks Changes in intrinsic molecular and microscopic structure of the collagen PG matrix Changes inf he intrisi. Mechanical property of the tissue

Question 27

Loosening of the collagen network allows

Answer 27

PG expansion and tissue Decrease stiffness Increased permeability

Question 28

Lubricin

Answer 28

Superficial zone protein

Question 29

Interfacial wear

Answer 29

Bearing surfaces direct contact with no lubricant film separating them Adhesion or abrasion

Question 30

Fatigue wear

Answer 30

Accumulation of microscopic subsurface damage under repetitive stressing Repeated high loads iced short period or repeated low loads over extended period

Question 31

Fissure and erosion

Answer 31

Delamination of superficial zone

Question 32

Fibrillation

Answer 32

Whispy looking fibers

Question 33

Fibril realignment and uncrimping

Answer 33

Toe region