joint physiology Flashcards
What are the functions of the synovial fluid?
- lubrication
2. provision of nutrition to cartilage
What component of the synovial fluid mainly contributes to its viscosity?
Hyaluronic acid (mucin)
What cells produce the synovial fluid?
Synovial cells (fibroblasts) in the synovial membrane
Rapid joint movement _______ viscosity and _______ elasticity of the synovial fluid.
decreases viscosity
increases elasticity
What is the normal upper limit of total white cell count in the synovial fluid? What is the upper limit of Polymorphs?
<200 WBC/mm3
<25 PMN/mm3
Due to inflammation, the viscosity of the synovial fluid is lower (T/F)
True
What are the 4 zones of the articular (hyaline) cartilage?
- superficial zone
- middle zone
- deep zone
- calcified zone
What are the components of the ECM (extracellular matrix) of the articular/hyaline cartilage?
- water - 70%
- Type II collagen - 20%
- proteoglycans - 10%
Collagen and water composition tend to increase with age (T/F)
False
both decrease with age
The articular cartilage is avascular (T/F)
true
-receives nutrients via synovial fluid
What cells produces the Extracellular matrix?
Chondrocytes
TNF-alpha and IL-1 ______ proteoglycan synthesis.
inhibit
-catabolic factors
Tumour growth factor and Insulin-like growth factor ______ proteoglycan synthesis.
stimulate
-anabolic factors
Serum and synovial fluid keratin sulfate indicates….
increased cartilage degradation
Synovial cell proliferation and inflammation cause _____ ______
rheumatoid arthritis
