joints, synovial fluid and cartilage Flashcards Preview

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Flashcards in joints, synovial fluid and cartilage Deck (21)
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1
Q

types of joints

A

fibrous
cartilaginous
synovial

2
Q

examples of fibrous joints

A

cranial sutures
periodontal ligament
interosseus membranes

3
Q

primary cartilaginous joint

A

just hyaline cartilage

4
Q

secondary cartilaginous joint

A

hyaline and fibrocartilage

5
Q

types of synovial joint (6)

A
plane 
condylar 
hinge
saddle 
pivot
ball + socket
6
Q

what factors contribute to joint stability

A
  • shape of articulating surfaces
  • muscles
  • capsules and ligaments
7
Q

types of cartilage in synovial joints

A

hyaline (articular)

fibrocartilage

8
Q

superficial layer of articular cartilage

A

flattened chondrocytes that produce collagen + glycoproteins (e.g. lubricin)

9
Q

transitional layer of articular cartilage

A

round chondrocytes that produce proteoglycans (e.g. aggrecan)

10
Q

glycoproteins e.g. lubricin

A

proteins to which oligosaccharide chains are attached

i.e. more a protein than a carbohydrate

11
Q

proteoglycans e.g. aggrecan

A

proteins that are heavily glycosylated (protein core to which 1+ GAGs are attached)
i.e. more carbohydrate than protein

12
Q

glycosaminoglycans (GAGs) e.g. hyaluronic acid

A

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

13
Q

cartilage properties

A

avascular
aneural
alymphatic

14
Q

does synovium have an epithelial lining

A

no, there is direct exchange of O2, CO2 and metabolites between blood and synovial fluid

15
Q

what produces synovial fluid

A

synoviocytes

16
Q

type a synoviocyte

A

look like macrophage
remove debris
contribute to synovial fluid production

17
Q

type b synoviocyte

A

fibroblast like

main producer of synovial fluid

18
Q

functions of synovial fluid

A

nutrition of articular cartilage
removal of waste products
lubrication –> less friction –> less wear

19
Q

how are joints lubricated

A
  • Boundary: glycoproteins bins to receptors on articular surfaces to form a thick film
  • Hydrodynamic: surfaces kept apart by liquid pressure, viscosity changes with load + velocity of movement
  • weeping: fluid present in cartilage is squeezed out into synovial cavity to increase fluid volue
20
Q

what are bursae

A

small sac-like cavities that contain fluid and are lined by synovial membrane
located subcutaneously between bony prominences or tendons
facilitate movement with reduced friction

21
Q

changes with ageing

A

viscosity of synovial fluid increases –> slower joint movements + reduced lubrication
decreased cartilage water content –> reduced shock absoption