ILA 11 - MSK

Question 1

What are the main bone cells, how do they appear histologically?

Answer 1

1. Osteoblasts - Contain lots of RER for synthesis of T1 collagen, proteoglycans and glycoproteins
   - deposit osteoid
2. Osteoclasts - largest cells, multinucleated, stain pink due to acid, they live in resorption bays
3. Osteocysts - the have long processes for communication and lie enclosed in layer of secreted matrix - in LACUNAE
   - cells are flat with less RER, golgi apparatus and more nuclear chromatin

Question 2

What is periosteum?

Answer 2

A dense fibrous outer layer of collagen and fibroblasts

-bundles of collagen fibres penetrate the bone matrix and innermost layer contains osteoprogenitor cells

Question 3

Name two types of bone

Answer 3

1. Woven bone - first to appear = random disposition of fine collagen fibres
2. Lamellar bone - organised in parallel layers around the centre Haversian canal, each complex of bone vessels, nerves and loose connective tissue is called an osteon

Question 4

How do central canals communicate

Answer 4

Through perforating canals - volkman’s canals