Biomechanics And Kinesiology - Articular Cartilage Flashcards Preview

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Flashcards in Biomechanics And Kinesiology - Articular Cartilage Deck (17):
1

Main functions of articular cartilage

- allows for movement with minimum friction
- deforms more readily than bone
- distributes loads over joint surfaces
- decreases contact surfaces

2

Chondrocytes

- manufacture, secrete, organise and maintain organic component of ECM

3

Wear

- unwanted removal of material from solid surfaces by mechanical action

4

Two types of wear

- interfacial wear
- fatigue wear

5

Interfacial wear

- occurs when two moving surfaces come into contact with little or no lubrication between them

6

Two types of interfacial wear

- adhesive wear
- abrasive wear

7

Interfacial adhesive wear

- occurs when surface fragments adhere to each other when surfaces meet and tear away

8

Interfacial abrasive wear

- occurs when a soft material is scraped by a harder one

9

Fatigue wear

- due to accumulation of microscopic damage under repetitive stressing

10

Two types of joint lubrication

- boundary lubrication
- fluid-film lubrication

11

Boundary lubrication

- prevent opposing surfaces touching

12

Five types of fluid-film lubrication

- hydrostatic (weeping) lubrication
- hydrodynamic lubrication
- squeeze-film lubrication
- elastohydrodynamic lubrication
- boosted lubrication

13

Hydrostatic (weeping) lubrication

- pressure created by muscle contraction around joint, compresses and deforms articular cartilage
- fluid weeps out forming a protective layer

14

Hydrodynamic lubrication

- non-parallel joint surfaces slide on each other forming a converging wedge of fluid
- this creates a lifting pressure as joint movement drags fluid into the gap

15

Squeeze-film lubrication

- as articular surfaces move together they squeeze fluid film out of area of impending contact

16

Elastohydrodynamic lubrication

- pressure generated in fluid-film deforms surfaces

17

Boosted lubrication

- as articular surfaces move closer, becomes more difficult for fluid-flim to escape from gap