Joints Flashcards
What are the 3 major types of joitns?
Fibrous
Cartilaginous
Synovial
Subtypes of Cartilaginous joint?
Primary = Hyaline cartilage only Secondary = Hyaline & Fibrocartilage
What is a fibrous joint + some examples?
Fibrous connective tissue between 2 bones, specifically collagen.
Periodontal ligament, cranial sutures & interosseous membranes
Describe the structure of a synovial joint?
Synovial cavity filled with fluid encased in a synovial membrane.
All inside a fibrous capsule with articular cartilage on the outside
What are the 6 types of synovial joint?
Hinge - Knee Pivot - Atlas & Axis Ball & Socket - Shoulder Saddle - Thumb Condylar - Atlas & Skull Plane - vertebral facets
Describe the vasculature, lymphatic drainage and nerves supply of a cartilage?
Avascular
Alymphatic
Aneural
Hence why synovial fluid is required to remove waste/supply articular cartilage in synovial joints
What do we call the synovial membrane and what does it do?
The synovium
Produces synovial fluid and drains it through the capillaries
What are the types of synoviocytes
Type A - resemble macrophages & remove debris (somewhat contribute to fluid)
Type B - Resemble fibroblasts and primarily produce synovial fluid
What makes up synovial fluid?
1) Hyaluronic Acid
2) Lubricin
3) Fluid component comes from plasma
Functions of synovial fluid?
Provide Nutrition to cartilage
Drain waste
Lubrication
Name 3 types of lubrication?
Boundary
Hydrodynamic
Weeping
Describe boundary lubrication?
Glycoproteins e.g. lubricin bind to receptors on the articular surface to form a thin film
Describe hydrodynamic lubrication?
Liquid pressure keeps surfaces apart
The viscosity of the fluid changes with load and velocity on the joint
Describe weeping lubrication?
High load causes the fluid in the cartilage to be squeezed into the synovial cavity
What 3 factors affect joint stability?
- Shape of articulating surface
- Capsule & Ligament strength
- Muscles e.g. the rotator cuff muscles on your shoulder