OA Etiology and Biochem

Question 1

Properties of glycosaminoglycans

Answer 1

Highly negatively charged
Hydrophilic
Stain strongly with metachromic stains
Offer resiliency to the cartilage, compressibility, drawing water in and out

Question 2

Inflammation mechanisms of OA

Answer 2

Synovitis
Crystals
Chondrocytes (IL-1)
Immune mechanisms

Question 3

Synarthroses

Answer 3

Ex: suture lines of skull
Fused and no mobility
Thin interlocking fibrous tissue

Question 4

Amphiarthroses

Answer 4

ex: symphysis pubis
Minimal mobility
Fibrocartilage between bones

Question 5

Diarthroses

Answer 5

Mobile joints
Occur in all of the peripheral joints in limbs and TMJ
Surrounded by a fibrous capsule and lined by synovium

Question 6

Entheses

Answer 6

Where tendons and ligaments insert into bone

Question 7

Space narrowing

Answer 7

When the bones look like they are touching on xray due to loss of the spacer effect of cartilage

Question 8

Hyaluronic acid binding region

Answer 8

Hook at the end of a proteoglycan that allows multiple PG subunits to attach to a strand of hyaluronic acid to form PG aggregates

Question 9

2 main GAGs in the articular cartilage PGs

Answer 9

Chondroitin sulfate

Keratan sulfate

Question 10

3 metalloproteases and what they target

Answer 10

Collagenase 1/MMP 1 (targets type 2 collagen)
Stromylysin/MMP 3 (targets the PGs)
Collagenase 13/MMP 13 (also targets collagen

Question 11

MMPs are upregulated by what 2 things?

Answer 11

IL-1 and plasmin