Bone

Question 1

What are the functions of bones?

Answer 1

• structural support
• protection of soft organs and tissues
• allow movement
• mineral storage
• source of stem cells (bone marrow)
• source of blood cells (bone marrow)

Question 2

Describe the bone composition

Answer 2

Inorganic ( ~ 65-70wt% dry)
• hydroxyapatite (90wt%)
Organic (~ 30-35wt% dry)
• collagen (85-90wt%)
• other proteins
• cells

Question 3

What are the classifications of bones by shape?

Answer 3

Long (femur)
Short (carpal/wrist bone)
Flat (parietal bone from skull)
irregular (sphenoid from skull)

Question 4

What are the classifications of bones by structure?

Answer 4

▪ compact (cortical ) bone

▪ spongy (trabecular / cancellous) bone

Question 5

Describe Collagen Fibres

Answer 5

Collagen fibres, collagen fibrils, collagen molecules(triple helix), a-chains, amino acids (proline, hydroxyproline, glycine)

Question 6

What are Osteoblasts used for?

Answer 6

bone forming cells found on the bone surface (line up in single layer)

Question 7

What do Osteoclasts do?

Answer 7

bone resorbing cells found in the bone surface

Question 8

What do Osteocytes do?

Answer 8

former Osteoblasts that have become trapped in the matrix they deposited

Question 9

Describe the process of bone remodelling

Answer 9

(Resting Stage) Osteoblasts line the bone surface in a single layer,(Bone Resorption) Osteoclasts recruited and activated to rosorb the bone, (Transition) Osteoclast removal and Osteoblast move in, (Bone Reformation) matrix synthesis bone reforms