Joints and movement Flashcards
What are the three categories of joint?
Fibrous/synarthrosis
Cartilaginous/Amphiarthrosis
Synovial/diarthrosis
What are the advantages and disadvantages of a fibrous joint?
Very stable
Limited movement.
What are the two types of fibrous joint?
Syndesmosis- Bones linked by a fibrous sheet. Interosseous membrane.
Sutures- Bones fuse together. Skull
What are the advantages and disadvantages of a cartilaginous membrane?
Relatively stable but give more movement than fibrous.
What are the two types of cartilaginous membrane?
Primary- Synchondrosis. Bones linked by hyaline cartilage for growing.
Secondary- Symphyses. Bones linked by fibrocartilage such as intervertebral disks.
What are the advantages and disadvantages of synovial joints?
Relatively unstable but allow great range of movement.
What are the six types of synovial joint?
Pivot- Spine. Movement in one plane.
Ball + socket- Hip. Good range of motion.
Plane- Acromioclavicular. Two planes of movement. Slide over each other.
Hinge- Elbow. Good range of movement in one plane.
Saddle- Carpometacarpal joints. Good range in one plane and limited in another.
Condyloid- Metacarpophalangeal joint. Good range in one plane and limited in another.
What are the six main components of a synovial joint?
Bones Hyaline/articular cartilage Capsule Joint cavity Skeletal muscle and ligaments Bursa
What role does bone play in a synovial joint?
Levers for movement.
What role does hyaline/articular cartilage play in a synovial joint?
To allow for smooth movement.
What role does the capsule play in a synovial joint?
Outer layer of fibrous tissue for strength.
Inner layer of synovial membrane to secrete synovial fluid for lubrication.
What role does the joint cavity play in a synovial joint?
Holds synovial fluid and allows movement.
What role does the bursa play in a synovial joint?
Prevents friction and allows full range of movement.
What role does the skeletal muscle and ligaments play in a synovial joint?
Skeletal muscle- structure and mechanical movement.
Ligaments- Structure/hold joint together.
What is a simple synovial joint?
One involving only two bones.
What is a compound synovial joint?
One containing more than one pair of articular surfaces.
What are the roles of synovial fluid?
Lubrication
Delivery of nutrients and removal of waste from chondrocytes.
What are some components of synovial fluid?
Mucin
Mononuclear antibodies
Uric acid
Describe the general appearance of synovial fluid.
Clear colourless liquid that is highly viscous. WCC <200mm3
Describe inflamed synovial fluid.
Straw/yellow translucent liquid with low viscosity. WCC 2000-75000mm3
Describe septic synovial fluid.
Opaque fluid of variable viscosity and colour. WCC >100000mm3
What are the four zones of articular cartilage?
Superficial zone
Middle zone
Deep zone
Calcified zone
Where are chondrocytes found in articular cartilage?
Deep zone
What are the three components of articular cartilage ECM?
Water- 70%
Type 2 collagen- 20%
Proteoglycans- 10%
What stimulates catabolism of cartilage ECM?
TNF-alpha and IL-1
What stimulates anabolism of cartilage ECM?
TGF-beta and IGF-1
What are markers of cartilage degradation?
Keratin sulphate in serum and synovial fluid.
Type II collagen in synovial fluid.
What is a subliction of a joint?
Reduced area between two articular surfaces but with contact still present.
What is a dislocation of a joint?
Complete loss of contact between the two surfaces of a joint.