Joints, synovial fluid and cartilage Flashcards
Name the 3 types of joints
fibrous
cartilaginous
synovial
3 examples of fibrous joints
cranial sutures
periodontal ligament
interosseus membrane
What type of cartilage is in a primary and secondary cartilaginous joint?
primary = hyaline secondary = hyaline and fibrocartilage
alternative names for a primary and secondary cartilaginous joint
primary = synchondrosis secondary = symphysis
an example of a primary and secondary cartilaginous joint
primary - epiphyseal growth plate
secondary = intervertebral disc
4 common features of a synovial joint
synovial cavity
synovial membrane
fibrous capsule
articular cartilage
3 other features which a synovial joint may contain
ligaments
bursae
articular discs
List some types of synovial joints and an example of each
plane - facet joint in vertebrae condylar - wrist hinge - elbow saddle - thumb pivot - proximal radio-ulnar ball and socket - shoulder
3 things joint stability is determined by
shape of articulating surfaces
capsule and ligaments
muscles
What types of cartilage are in synovial joints and where are they both found?
hyaline lines epiphysis
fibrocartilgae in the fibrous cartilage
Briefly describe the superficial later of articular cartilage
flattened chondrocyted produce collagen and glycoproteins
horizontally arranged
example of glycoprotein
lubricin
Briefly describe the transitional layer of articular cartilage
round chondrocytes produce proteoglycans
diagonally arranged
example of proteoglycan
aggrecan
is water compressible?
no
Are glycoproteins and proteoglycans more protein or carbs?
g - more protein
p - more carbs
What is a glycosaminoglycan?
long unbranched polysaccharide which are highly polar and therefore attract water
example of GAG
hyaluronic acid
average cartilage thickness and the thickness of patella and interphalangeal joint
2-3mm
IP = 1mm
patella = 5-6mm
3 A’s of cartilage
avascular
aneural
alymphatic
How does cartilage get nourished and remove waste?
via synovial fluid
What produces synovial fluid?
synoviocytes in the synovial membrane
Does the synovium have an epithelial lining?
no
Type A synoviocytes
look like macrophages
remove debris
contribute to synovial fluid production
Type B synoviocytes
fibroblast like
main producer of synovial fluid
are type A or B synoviocytes the main producer of synovial fluid?
B
components of synovial fluid
viscous
hyaluronic acid and lubricin
fluid component from plasma
volume and turnover of synovial fluid
small volumes, high turnover
3 main functions of synovial fluid
nutrition of cartilage
removal of waste products
lubrication
How is the boundary part of lubrication achieved?
glycoproteins (lubricin) bind to receptors on articular surfaces and form a thin film
How is the hydrodynamic property of synovial fluid lubrication achieved?
surfaces kept apart by liquid pressure
viscosity changed with load and velocity
How is weeping of synovial fluid lubrication achieved?
fluid present in cartilage squeezed into synovial cavity to increase the fluid volume
What are bursae?
fluid filled sacs which reduce friction and can become inflamed - bursitis
2 main changes of joints with ageing and the overall consequence of this
viscosity of synovial fluid inc. - slow joint move and dec lubrication
water content of cartilage dec.- red. shock absorption
less protection of articular surfaces and increased risk of damage
