Joint Physiology Flashcards
seperate by cavity, united by fibrous capsule
synovial joint
Inner capusle of synovila joint is lined by …
synovial membrane
Synovial membrane contains
synovial cells which produce synovial fluid
articualr surfaces are covvered with …
cartilage
A pair of articular surfaces =
simple synovial (e.g. finger)
more than a couple of articualr surfaces =
compound synovial (e.g. elbow)
Synovial fluid: How much? + what does it do?
<3.5ml in adult knee
- lubricates joint,
- facilitates movement,
- minimises wear and tear,
- aids in nutirtion of cartilage,
- supplies chondrocytes with O2 and nutrients
Viscosity vaires with….
joint movement
Rapid movement =
decreased viscosity and increased elasticity
appearance of normal synovial fluid
clear and colourless
Inflamed or infected synovial fluid looks
straw to yellow due to WBC increase
Haemorrhagic arthritis causes fluid to look
red
Articular cartilage (hyaline) is compised of …
- Extracellular Matrix (70% -made of water)
- Collagen (20% - tensile stiffness and strength)
- Proteoglycans (10% - compression and load bearing)
Chondrocytes
synthesise and degrade Extracllular matrix of cartilage (>98% of volume). Normally the rate of degradation doesn’t exceed the rate it is replaced.
Markers of cartilage degradation:
- Serum + synovial keratin sulphate (increase with age and osteoarthritis)
- type II collagen in synovial fluid (useful in determining cartilage erosion)
