Bone Composition and structure

Question 1

What is osseous tissue

Answer 1

• collagen and hard minerals
• e.g. calcium, magnesium, phosphate

Question 2

what are the two types of bone

Answer 2

• cancellous / spongy bones
  
  • light and strong (trabeculae)
• compact bone
  
  • dense and tough

Question 3

what is the structure of a long bone?

Answer 3

• diaphysis (shaft)
  
  • thick layer of compact bone
• epiphysis (end of bone)
  
  • articular cartilage, spongy bone
• medullary canal (contains yellow bone marrow)
• periosteum

Question 4

what are the three types of bone cell

Answer 4

• osteoblasts (create)
• osteoclasts (break down)
• osteocytes (monitor)

Question 5

what is the micro-structure of bone

Answer 5

• osteon
  
  • haversian canal (contains blood vessels and nerves)
• perforating canals (opposite direction)
• lamallae

Question 6

what is osteogenesis

Answer 6

• formation of bone collar around hyaline cartilage model
• cavitation of the hyaline cartilage within the cartilage model
• invasion of internal cavities by the periosteal bud and spongy bone formation
• formation of the medullary cavity as ossification continues
• formation of the medullary cavity as ossification continues; appearance of secondary ossification centre in the epiphysis in preparation for stage 5
• ossification of the epiphyses; when completed; hyaline cartilage remains only in the epiphyseal plates and articular cartilage

Question 7

bone remodelling

Answer 7

• bone turnover
• 10% replaced each year approximately
• wolffs law