Bone growth Flashcards
When can bone growth begin?
6 weeks after fertilisation
What are primary centres of ossification?
-Diaphyses is primary
- Epiphysis remain cartilage
- Develop at different times depending on bone
What are secondary centres of ossification?
Epiphyses (same ossification process as primary centre)
- Separated from diaphysis by an epiphyseal plate
How does bone growth occur?
- Enabled by epiphyseal plates
- Formed of cartilage
- Begins at puberty (epiphyseal begins to fuse with diaphysis)
How does the bone grow in length and width?
Length: through growth plate
Width: appositional growth, OB activity produces lamellae, OCs mould shape and form medullary cavity
What is a joint?
- Holds bones together
- Where bones meet = articulation
- Involves bone shapes and soft tissues
- Allows free movement/control of movement
What soft tissues are associated with joints?
Different compositions depending on function
No inorganic components
Cartilage : hyaline (articular) and fibrocartilage
What is cartilages general composition?
Collagen fibres are ground substance, chondrocytes in lacuna
Blood vessels don’t penetrate cartilage
Nutrients diffused through matrix
What is hyaline (articular) cartilage?
- Collage fibres barely visible
- High water content in matrix
- Function : resist compression, moulds surfaces of bones where articulation occurs
- Smooth, frictionless surface
What is fibrocartilage?
- Collagen fibres form bundles throughout matrix
- Orientation of fibres align with stresses
Functions to resist tension and compression, acts as a shock absorber
What are ligaments?
- Connect bone-bone
- Function to restrict movement (lateral ligaments restrict movement medially)
- Elastin & collagen means they stretch and allow recoil
What are tendons?
- Connect muscle to bone
- Function = facilitates and control movement
- Contraction of muscles transmitted to bone
How does the amount of bony congruence affect amount of soft tissue support?
Less congruence = more soft tissue support needed
