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Flashcards in Bone Deck (27)
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1
Q

What are the four main functions of bone?

A
  1. Weight bearing/ support
  2. Protection (e.g. skull protecting brain)
  3. Mineral store
  4. Blood formation
2
Q

What is the difference between cortical and trabecular bone?

A

Cortical (Hard) bone is more compact than trabecular (spongy) bone

3
Q

What is the difference between the periosteum and the endosteum?

A

The periosteum is the outer membrane and the endosteum is the inner membrane.

4
Q

What are Haversion systems?

A

Compact bone organised into circular structures

5
Q

What is the difference between Haversion canals and Volkmann’s canals?

A

Haversion canals lead up the centre of Haversion systems.

Volkmann’s canals lead horizontally through Haversion systems.

6
Q

What is the other name for Haversion systems?

A

Osteons

7
Q

What are the 6 types of bone?

A
  1. Sutural bone
  2. Flat bone
  3. Long bone
  4. Short bone
  5. Irregular bone
  6. Sesamoid bone
8
Q

Where do sesamoid bones occur?

A

Where there is a risk of friction

9
Q

What are the two types of bone formation?

A

Intramembranous and Endochondral

10
Q

Describe endochondral bone formation.

A

Hyaline cartilage model is replaced by bone

11
Q

Describe intramembranous bone formation.

A

(Membrane becomes replaced by bone)
Mesenchymal cells develop into osteoprogenitor cells
Osteoprogenitor cells mature into osteoblasts
Osteoblasts deposit bone
Residual mesenchymal cells develop into blood vesseks and bone marrow.

12
Q

What bones are formed by intramembranous ossification?

A

Flat bones of skull, face, jaw and clavicle

13
Q

What three cells are present in bone?

A

Osteoblasts, Osteoclasts, Osteocytes

14
Q

What are the constituents of bone extracellular matrix?

A

Hydroxyapatite crystals
Type 1 Collagen
Water

15
Q

From what cells are osteoblasts formed?

A

Osteoprogenitor cells

16
Q

What is the function of osteoblasts?

A

Produce bone matrix and initiate calcification

17
Q

From what cells are osteoclasts formed?

A

Monocytes/ macrophages

18
Q

What is the function of osteoclasts?

A

Reabsorb bone matrix

19
Q

How are osteocytes formed?

A

From maturation of osteoblasts once surrounded by matrix.

20
Q

What is though to be the function of osteocytes?

A

Maintenance of bone matrix

Sense mechanical forces

21
Q

What is the role of canaliculi?

A

Connect lacunae to allow cell to cell communication

22
Q

From what compound are hydroxyapatite crystals formed?

A

Calcium phosphate

23
Q

What is the function of hydroxyapatite crystals in the extracellular matrix?

A

Makes bones stiff for support and gives high tensile strength.

24
Q

What is the role of the collagen found in the extracellular matrix of bone?

A

Allows flexibility of bone to make it less brittle.

25
Q

What processes characterise osteoporosis?

A

Greater reabsorption than formation

26
Q

What processes characterise Paget’s disease?

A

Increased reabsorption and Formation

27
Q

What process characterises osteopetrosis?

A

Decreased reabsorption