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Flashcards in Bone Deck (22):
1

Functions of Bone?

Weight bearing, support, protection and storage of minerals for blood formation.

2

What are the circular structures in compact bone called?

Osteones/Haversian systems

3

Central canal of compact bone name?

Haversian Canal

4

Horizontal perforating canal of compact bones name?

Volkmann's canal

5

What is placed around the haversian canal in compact bone?

Osteocytes and concentric rings of bone matrix (lamellaes)

6

Is spongy bone less or more dense than compact bone?

Less

7

Does spongy bone have haversion systems? If No what does it have?

No - has a network of lamellated trabeculae filled with bone marrow

8

What does the orientation of the trabeculae in spongy bone show?

Direction of mechanical force

9

Two types of bone formation?

Endochondral (long bones) and Intramembranous (flat bones, mandibles, maxilla, clavilcles)

10

How is endochondral ossification done?

Bone forms as a cartilage model Blood vessels invade the cartilage structure Cartilage replaced with bone, and cartilage kept in epiphyseal growth plate Growth plate eventually ossifies

11

How is intramembranous ossification done?

No cartilage phase

Mesenchymal cells develop into Osteoprogenitor cells that mature into osteoblasts that start depositing bone

Residual mesenchymal cells develop blood vessels and bone marrow

12

What 3 cells make up bones?

Osteoblasts Osteoclasts Osteocytes

13

What does the mineral hydroxyapatite do in bone?

Makes bones stiff and able to support structures and has a high strength under compression

14

What does collagen do in bone?

Gives bone some flexibility reducing risk of fracture High strength under tension

15

What do osteoblasts do?

Produce bone matrix, once surrounded by matrix becomes an osteocyte

16

What do osteocytes do?

Just mature bone, function not well understood

17

What do osteoclasts do?

Reabsorb bone matrix

18

What causes osteoporosis?

Re-absoprtion is greater than bone formation

19

What causes pagents disease?

When re-absorption and formation both are running at high rates

20

What causes osteopetrosis?

When reabosption is too low

21

What controls bone mass?

Genes and enviroment

22

Do mechanical loads regulate bone mass?

Yes