Flashcards in Lecture 8: Joint Structure Deck (15):
General Cartilage Composition
- Collagen fibres in a ground substance
- Chondrocytes live in lacuna
- Nutrients diffused through matrix when joint moves
Describe the structure of hyaline cartilage
- Collagen fibres are barely visible
- High water content in matrix
Describe the function of hyaline cartilage
- Resist compression
- Provide smooth frictionless surface
- Moulds where there's articulation
Describe the structure of Fibrocartilage. Give examples
- Collagen fibres bundled in matrix
- Orientation of fibres aligns with stresses
- eg. meniscus in knee joint deepens articulation
Describe the function of Fibrocartilage
- Resists compression and tension
- Can adapt shape based on stresses
What is bony congruence? What effect does it have on soft tissue?
- The bone surfaces that articulate
- More soft tissue is needed where there is less bony congruence, to enable movement
- More BC = stable joint (hip)
Describe the function of the meniscus
- Contains concave discs of fibrocartilage
- Deep articulation = more surface area for articulation and movement
- Spreads weight over higher area
What is a joint?
- Holds bones together
- Found where bones meet / articulate
- Involves soft tissue
- Allows free / controlled movement
What happens when the meniscus is moved?
- Weight is concentrated on a smaller area
What type of joint is found in the intervertebral disc?
- Fibrocartilage (between disc bodies)
Why is fibrocartilage found between vertebral discs and not hyaline cartilage?
- Disc is attached to outside of vertebral bodies
- When we move our torso we need bones to be held together (tensile forces)
What is the nucleus pulposus?
- The inner core of the vertebral disc made of gel-like substance
- Moves like a ball bearing, helping to resist compressing forces
What are some features of tendons and ligaments?
- Collagen (aligned to wear stresses are)
- Fibroblasts + (cytes)
- Function = Resist tension
- Able to heal self but very VERY slowly compared to bone
Describe the function of ligaments and give an example
- Bone to bone
- Restrict movement
- Movement is restricted "away from itself"
- eg. ankle joint - lateral resists adduction