Bones Flashcards
What is the skeleton split into?
Axial and appendicular
What is DIAPHYSIS
Compact bone surrounding a medullary cavity
What is EPIPHYSES?
Spongy bone within compact bone and cartilage on the joint surface
What are the bones forming vertebral column?
Cervical (7)
Thoracic (12)
Lumbar (5)
Sacral (5)
How many pairs of ribs are there and what do they form?
12 pairs
They from the thoracic cage
Functions of bone
- weight bearing/support
- protection
- mineral store for strength
- blood formation (red bone marrow)
What system is in the COMPACT bone?
Osteons/Haversian systems
What’s the other names for spongy bone?
Cancellous, trabecular bone or dipole
What cells are bone composed of?
Osteoclasts
Osteoblasts
Osteocytes
What type of cell is found on bone surface and what is their function?
Osteoclasts reabsorb bone matrix by releasing acid to dissolve it
What type of bone cell is immature and what is its function?
Osteoblasts produce bone matrix and initiate calcification
What type of bone cell becomes an osteocyte once surrounded by matrix?
Osteoblasts
Where are osteocytes found?
Inside lacunae
What connects lacunae to each other?
CANALICULI which then allows for communication between cells
Where are osteoclasts derived from?
Haemopietic lineage
Where are osteoblasts derived from?
Mesenchymal lineage
What are the two types of ossification?
Endochondral ossification
Intramembranous ossification
Describe ENDOCHONDRAL ossification
- bone forms a cartilage model first
- blood vessels invade cartilage
- cartilage replaced with bone
- cartilage remains in EPIPHYSEAL growth plate
- growth plate eventually ossifies
Describe INTRAMEMBRANOUS ossification
- no cartilage ‘model’!
- mesenchymal cells develop into osteoprogenitor cells
- that mature into osteoblasts
- that start depositing bone
- residual mesenchymal cells develop blood vessels and bone marrow
What type of bone formation occurs in adults?
Intramembranous ossification
What are the two types of bone growth?
Appositional
Interstitial
