Joint Inflammation and Degenerative Joint Disease Flashcards
what is the role of type A cells in the intima of the synovial membrane?
phagocytic
what do type B cells in the intima of the synovial membrane do?
produce collagen and hyaluronic acid
how is the haversian system oriented to the joint?
parallel to joint
what is the principal working tissue of the joint?
articular cartilage
what type of collagen is most abundant in joints?
type II
what is the hallmark of osteoarthritis?
enzymatic degradation of cartilage
what are the proposed mechanisms for development of osteoarthritis?
defective cartilage
physical changes to subchondral bone
mechanical forces damage healthy cartilage
what is seen grossly with degradation of articular cartilage?
fibrillation
erosions
wear lines
how are type B cells in the intima of the synovial membrane derived?
fibroblast derived
how does articular cartilage get nutrition in adults?
synovial fluid
what is the main component of extracellular matrix in articular cartilage?
proteoglycans and collagen
what are the cartilage zones?
superficial/tangential
middle/transitional
deep/radial
calcified
what produces collagen in joints?
chondrocytes
what do collagens provide in joints?
structural support
tensile strength
type II most abundant
what do proteoglycans provide in joints?
compressive stiffness
what is osteoarthritis like in small animals and humans?
age related, progressive
underlying joint injury or trauma
what is osteoarthritis like in equine?
synovitis or capsulitis
repetitive trauma
what physical changes to the subchondral bone can lead to osteoarthritis?
increased sclerosis
fails to deform under normal loads
mechanical damage
what does the synovium release in osteoarthritis?
lysosomal enzymes
prostaglandins
oxygen free radicals
cytokines
what precedes the morphologic breakdown in osteoarthritis?
enzymatic degradation
what do free radicals do?
cleave prostaglandins, collagen, and hyaluronic acid
what does substance P do?
stimulates cytokine release
what does the subsynovial stroma provide?
rich blood supply
produces synovial fluid
nutrient and waste exchange
what is visible histologically with degradation of articular cartilage?
fibrillation
vertical clefts
chondrocyte necrosis
full thickness cartilage loss
