Joints, Synovial Fluid and Cartilage Flashcards
What are the different structural classifications of joints?
1 - Fibrous
2 - Cartilaginous
3 - Synovial
What are the distinguishing features of each of the joint types?
Fibrous - very strong joints with little movement
Cartilaginous - Layers of cartilage instead of fibrous tissue
Synovial - The most complex type of joints and also the joints that can perform the most movement
Where in the body can fibrous joint types be found?
1 - Cranial sutures
2 - Peridontal ligament (between tooth and collagen fibres)
3 - Interosseus membranes (stops radial & ulnar bones being pulled apart)
Where in the body can cartilaginous joints be found?
1 - Growth plates of long bones
2 - Vertebral discs & their vertebral bodies
What is the difference between primary cartilaginous and secondary cartilaginous joints?
Primary - Only Hyaline cartilage
Secondary - Hyaline cartilage & Fibrocartilage
Where in the body can synovial joints be found?
1 - Knees & Elbows (Hinge)
2- Vertebral column facet joints (Plane)
3 - Shoulder (Ball & Socket)
4 - Radio-Ulnar (Pivot)
5 - Thumb (Saddle)
6 - Atlanto-axial joint (Condylar)
What are the components of synovial joints?
1 - Articular discs
2 - Ligaments
3 - Bursae
What is the structure & function of hyaline cartilage?
Structure:
- Superficial layer: Flattened chondrocytes which produce collagen and glycoproteins (lubricin)
- Transitional layer: Round chondrocytes which produce proteoglycans such as aggrecan
- >75% water
Function:
- Due to high water content, hyaline cartilage is very good at cushioning joints
- Horizontally oriented fibres of superficial layer increases the strength of the joint
What are the important molecules found within joints?
Glycoproteins - Proteins to which oligosaccharides are attached, e.g. Lubricin
Proteoglycans - Proteins which are heavily glycosylated, e.g. Aggrecan
Glycosaminoglycans - Long, unbranched polysaccharides, e.g. Hyaluronic acid
What are the main components of synovial fluid?
1 - Hyaluronic acid
2 - Lubricin
3 - Fluid component from blood plasma
What is the function of synovial fluid?
1 - Nutrition of cartilage
2 - Removal of waste products
3 - Lubrication of joints