Physiology: Physiology of Joints Flashcards
Describe the structure of synovial joints
Bones separated by a cavity which contains synovial fluid, and united by a capsule
What effect do TNF-⍺ and IL-1 have on the extracellular matrix of articular cartilage?
Catabolic - stimulate proteolytic enzymes and inhibit proteoglycan synthesis
What is a simple synovial joint?
A synovial joint with only one pair of articular surfaces e.g. metacarpophalangeal joint
What is the function of collagen in articular cartilage?
Maintains cartilage architecture and provides tensile stiffness and strength
What effect do TGF-β and IGF-1 have on the extracellular matrix of articular cartilage?
Anabolic - stimulate proteoglycan synthesis and counteract effects of IL-1
What conditions would increase synovial fluid WBC?
Inflammatory arthritis and septic arthritis
Which type of collagen is mostly present in articular cartilage?
Type II (elastic)
What are cartilaginous joints?
Bones united by cartilage e.g. intervertebral discs
What creates the high viscosity of synovial fluid?
Hyaluronic acid (mucin) produced by the synovial cells
When would synovial fluid turn red?
In traumatic synovial tap and in haemorrhagic arthritis
Name the cells that synthesise, organise and degrade the extracellular matrix of articular cartilage
Chondrocytes
Which form of cartilage usually forms articular cartilage?
Hyaline
What is articular cartilage?
The cartilage that covers the articular surfaces of bones in a synovial joint
What is the function of water in articular cartilage?
Maintains the resiliency of the tissue and contributes to the nutrition and lubrication system
What is the function of articular cartilage?
Provides a low friction lubricated gliding surface, and distributes contact pressure to subchondral bone