1. Bone Growth, Organisation and Repair Flashcards
Recall the mechanical properties of bone
- Cable-like flexibility and resistance to tension
2. Pillar-like flexibility and resistance to compression
What is the endosteum and what is its function?
Incomplete cell layer lining the marrow cavity: very active during bone growth and repair
Recall the blood supplies to bone
Periosteal arteries
Nutrient arteries
Metaphysial and epiphysial arteries
Recall 2 features of note of the metaphysial and epiphysial vessels
- Supply the ENDs of long bones
2. Only present in GROWING skeleton
What are the 2 different types of ossification
Intramembranous
Endochondreal
Summarise the differences between intramembranous and endochondreal ossification
IM = directly from mesenchyme EC = mesenchyme differentiates to cartilage before forming bone
Which bones undergo intramembrinous ossification?
Skull, mandible and clavicle
Define interstitial growth of bone
Expansion of cartilage matrix
Define appositional growth of bone
New growth of cartilage at the outer surface of bone
Where does primary ossification take place and how does it grow?
Diaphysis
Grows in both directions
Appositional growth
What is the epiphysial plate?
The cartilaginous area between the diaphysis and epiphysis that persists until growth is complete
Which small bone undergoes secondary ossification?
Calcaneus
Recall the 4 steps in growth of bone diameter
- Appositional growth
- Osteoblasts + osteoclasts create ridges and grooves on surface
- Vasculature built in these grooves
- Osteoblasts build new osteons around vessels
What is the function of osteocytes?
Maintain matrix
Give an overview of bone repair following a fracture
Heamatoma Progenitors --> osteoblasts Soft callus Endochondral ossification woven bone cancellous bone cortical bone
