Lecture 4 Flashcards
(24 cards)
What are the two synovial joint structures
Fibrous layer (outer layer)
Synovial membrane (inner layer)
What are the 2 cell types that line the synovial membrane
Type A synoviocytes: immune function
Type B synoviocytes: synovial fluid production
What is type A synoviocytes ?
Macrophages that secrete immunoglobulins/lysosomal enzymes that PROTECT SYNOVIAL FLUID from pathogens
What is type B synoviocytes
Produce and secrete synovial fluid production
(T/F) the synovial membrane is not vascularized
False, its highly vascularized brings nutrients to the bloodstream and removes wastes from the blood stream
What is Hilton’s Law
Muscular reflexes that create protective muscle spasms surrounding an injured joint
What maintains the viscosity of synovial fluid
Hyaluronic acid
Lubricin
What is responsible for articular cartilage turnover in the synovial fluid
Proteinases
Collagenases
What are the 4 compositions articular cartilage?
Water 60-80%
Proteoglycans 10-20%
Collagen fibers 10-20%
Chondrocytes 2%
What is the function of chondrocytes in articular cartilage
Produce/maintain ECM
What is type 2 collagen in collagen fibers
Responsible for mechanical stress
Has surface and a deeper layer
Surface - smooth frictionless
Deeper - absorbs compressive forces
What is the function of proteoglycans
Regulate fluid flow in/out of cartilage and to provide physical space between collagen fibers
What is the function of water in articular cartilage
Helps provide resistance to compressive forces
What regulates the amount of water content in articular cartilage
Proteoglycans and collagen
What is zone 1 in articular cartilage
Superficial zone
Reduce friction, smooth
No blood supply
What is zone 2 & 3 in articular cartilage
Middle and deep layers
Transitional zone
Absorbs compressive forces
No blood supply
What is zone 4 in articular cartilage
Calcified cartilage layer
Anchors cartilage to bone
Bloody supply
What regulates the rate of fluid flow into articular cartilage
Proteoglycans
Proteins
Collagen
What is anabolic signaling
Synthesize ECM
“Healthy cartilage”
What is catabolic signaling
Breakdown of ECM
“Unhealthy cartilage”
(T/F) too much or too little weight bearing promotes optimal pro- anabolic signaling in articular cartilage
False
Promotes catabolic breakdown of cartilage
Healthy weight promotes pro anabolic signaling
(T/F) articular cartilage does not have direct blood supply
True
Subchondral bone below tidemark has blood supply
What is tidemark
Interface between uncalcified and calcified
(T/F) articular cartilage is innervated by nerves
False
Subchondral bone below tidemark has nerves
