Physiology of Joints Flashcards
what are bones separated by in a synovial joint?
cavity containing synovial unit
what are bones united by in a synovial joint?
fibrous capsule
ligaments
tendons
bursae
what is the inner aspect of fibrous capsule lined with?
synovial membrane
what kind of tissue is the synovial membrane?
vascular connective tissue with capillary networks and lymphatics
what kind of cells are present in the synovial membrane
synovial cells
what do synovial cells do?
produce synovial fluid and mucin (hyaluronic acid)
another name for synovial cells
fibroblasts
another name for articular cartilage
hyaline cartilage
what is the difference between a simple and compound synovial joint?
simple= 1 pair of articular surfaces, compound= more than 1 pair of articular surfaces
main role of joints?
structural support
purposeful motion
how do joints create stability?
synovial fluid
ligament attachments
what does synovial fluid do?
lubricates joint,
facilitates joint movement, aids in nutrition of articular cartilage and chondrocytes
is synovial fluid viscous or thin?
viscous
why is synovial fluid viscous?
presence of hyaluronic acid aka mucin
why is articular cartilage so in need of nutrients?
it is avascular so needs its nutrients delivered by a medium
main cells contained in synovial fluid?
mononuclear leukocytes
how does synovial fluid viscosity and elasticity change during rapid movement
decreased viscosity
increased elasticity
when do polymorph levels increase?
inflammation
infection
what should synovial fluid look like?
clear and colourless
when would synovial fluid turn red?
traumatic synovial tap
haemorrhagic arthritis
when would you suspect a synovial fluid sample was septic?
opaque appearance
high WBC count
functions of articular cartilage?
prevents wear and tear
distributes contact pressure to subchondral bone
which part of the articular cartilage has the highest volume
extracellular matrix
4 zones of articular cartilage?
superficial
middle
deep
calcified
which type of collagen contributes most to the elastic behaviour of cartilage?
type 2
what makes up the major component of cartilage?
water
which type of collagen decreases with age?
type 2
where is most of the articular cartilage’s water distributed?
near articular surface
what is the role of collagen in cartilage?
provides stiffness and strength
maintains architecture
where is proteoglycan found in cartilage?
middle and deep zones
what is the role of proteoglycan in cartilage
compression i.e load bearing
what cells maintain and organise the extracellular matrix?
chondrocytes
what do catabolic factors of the ECM do?
stimulate proteolytic enzymes and inhibit proteoglycan synthesis
give examples of catabolic factors of cartilage matrix turnover?
TNFa
IL-1
what do anabolic factors of the ECM do?
stimulate proteoglycan synthesis and counteract effects of IL-1
give examples of anabolic factors of the ECM?
TGF-b
IGF-1
name markers of cartilage degradation
increased type 2 collagen
increased serum and synovial keratin sulfate
what causes rheumatoid arthritis?
synovial cell proliferation and inflammation
what causes soft tissue rheumatism?
injury and inflammation to periarticular structures
what are the pathological effects on subchondral bone from osteoarthritis?
thickened capsule cyst formation sclerosis fibrillated cartilage hypertrophy osteophyte formation
name the cell types that drill into bone
osteoclasts
