Joints, Synovial Fluid And Cartilage

Question 1

What are the 3 types of joints?

Answer 1

Fibrous, cartilaginous, synovial

Question 2

3 examples of fibrous joints?

Answer 2

Cranial sutures, periodontal ligament, interosseus membranes

Question 3

Types of cartilaginous joints?

Answer 3

Synchondrosis (primary cartilaginous), symphysis (secondary cartilaginous)

Question 4

Difference between primary and secondary cartilaginous joint?

Answer 4

Primary- only hyaline cartilage

Secondary- hyaline and fibrocartilage

Question 5

Synovial joints common features?

Answer 5

Synovial cavity, articular cartilage, synovial membrane, fibrous capsule

May also contain- articular discs, ligaments, bursar

Question 6

Types of synovial joints?

Answer 6

Plane, hinge, pivot, condylar, saddle, ball and socket

Question 7

How are joints stabilised?

Answer 7

Shape of articulating surfaces, capsule and ligaments, muscles

Question 8

Types of cartilage in synovial joints?

Answer 8

Hyaline cartilage, fibrocartilage

Question 9

What are the layers called of articular cartilage?

Answer 9

Superficial/ tangential layer and

Transitional layer

Question 10

Describe the superficial/ tangential layer of articular cartilage

Answer 10

Flattened chondrocytes that produce collagen and glycoproteins (eg lubricin)

Question 11

Describe the transitional layer of articular cartilage?

Answer 11

Round chondrocytes that produce proteoglycans such as aggrecan

Question 12

Does articular cartilage contain water?

Answer 12

Yes it is >75% water

Question 13

What is the collagen orientation in articular cartilage?

Answer 13

Varys form superficial to deep layers,
Horizontal@ articular surface
Diagonal @ centre
Horizontal-ish @ deep

Question 14

What is lubricin?

Answer 14

A glycoprotein

Question 15

What is aggrecan?

Answer 15

A proteoglycans

Question 16

WHat is hyaluronic acid?

Answer 16

A glycosaminoglycan (GAGs)

Question 17

Define a glycoprotein

Answer 17

Proteins to which oligosaccharide chains are attached i.e more protein than a carbohydrates e

Question 18

What is a proteoglycan

Answer 18

Proteins that are heavily glycosylated i.e tend to be more carb than protein

Question 19

What is a glycosaminoglycan

Answer 19

Long unbranched polysaccharides, which are highly polar and thus attract water

Question 20

Average thickness of articular cartilage?

Answer 20

2-3mm

Question 21

Thickness of interphalangral joint?

Answer 21

1mm

Question 22

Thickness of patella?

Answer 22

5-6mm

Question 23

What is present in the synovium?

Answer 23

Synoviocytes and synovial fluid,

No epithelial lining

Question 24

What do synoviocytes produce?

Answer 24

Synovial fluid

Question 25

What is the function of the synovium?

Answer 25

Direct exchange of O2, CO2 and metabolites between blood and synovial fluid

Question 26

Describe a Type A synoviocyte?

Answer 26

Look like macrophages,
Remove debris,
Contribution to synovial fluid production

Question 27

Describe Type B synoviocytes

Answer 27

Fibroblast like,

Main producer of synovial fluid

Question 28

Composition of synovial fluid?

Answer 28

Viscous fluid,
Hyaluronic acid and lubricin,
Fluid component (from blood plasma)

Question 29

Function of synovial fluid?

Answer 29

Nutrition of cartilage,
Removal of waste products,
Lubrication

Question 30

Types of lubrication demonstrated by synovial fluid

Answer 30

Boundary, hydrodynamic, weeping

Question 31

Boundary lubrication?

Answer 31

Glycoproteins such as lubricin bind to receptors on articular surfaces to form a thin film

Question 32

Hydrodynamic lubrication

Answer 32

Surfaces kept apart by liquid pressure,

Viscosity changes withload and velocity of movement

Question 33

Weeping lubrication?

Answer 33

Fluid that is present in the cartilage is squeezed out into the synovial cavity to increase fluid volume

Question 34

What is the bursae?

Answer 34

A synovial membrane that is fluid filled and reduces friction

Question 35

How can ageing affect your synovial fluid?

Answer 35

There is increased synovial fluid viscosity:
— causing slower joint movements,
— reduced lubrication

Decreased water content of cartilage:
—reduced shock absorption