Synovial fluid, joints and cartilage

Question 1

name firbous joints

Answer 1

crainial sutures, peridonatal ligament, interosseus membranes.

Question 2

what are the types of cartilaginous joints and define them

Answer 2

primary (hyaline), secondary (hyaline and fibrocartilage)

Question 3

what are the types of synovial joints and give examples of each

Answer 3

plane (vertebrae), hinge (elbow), pivot, condylar (atlas), saddle (thumb), ball and socket (shoulder).

Question 4

describe hyhaline (articular) cartulage histologically

Answer 4

Superficial/tangential layer:flattened chondrocytes that produce collagen and glycoproteins (e.g. lubricin)
Transitional layer: round chondrocytes that produce proteoglycans such as aggrecan
Change in collagen orientation from superficial to deep layers. >75% water (water = incompressible)

Question 5

define some of the molecules made up of proteins and carbs.

Answer 5

glycoproteins (lubrin) - proteins to which oligosaccharides are attatched to. Proteoglycans (aggrecan) - proteins which are heavily glycosylated. Glycosaminoglycans (hyaluronic acid)

Question 6

outine the avascular aspects of cartilage and how synovial fluid is produced and its function

Answer 6

produced by the synoviocytes in the synovial membrane, has a rich capillary network and no epithelial lining. The synovial fluid allows the direct exchange of oxygen and co2 and other metabolites between the blood and synovial fluid. Lubrication and nutrition of the cartilage.

Question 7

what are the two different types of synoviocytes and define them

Answer 7

A - look like macrophhages, remove bedris, contribute to synovial fluid production. B - fibroblast like, main producer of synovial fluid.

Question 8

what is te composition of synovial fluid?

Answer 8

viscous, hyaluronic acid and lubrin. Fluid component from blood plasma.small volumes and rapid turnover.

Question 9

define boundary lubrication

Answer 9

Glycoproteins such as lubricin bind to receptors on articular surfaces to form a thin film

Question 10

define hydrodynamic lubrication

Answer 10

Surfaces kept apart by liquid pressure. Viscosity changes with load and velocity of movement

Question 11

define weeping lubrication

Answer 11

Fluid that is present in the cartilage is squeezed out into the synovial cavity to increase fluid volume