Intro To Bone

Question 1

Mechanical properties of bones

Answer 1

Cable like flexibility and pillar like stiffness

Question 2

What are bones resistant to

Answer 2

Compression and tension

Question 3

What feature gives bones resistance to tension

Answer 3

Framework consists of collagen and other bone proteins

Question 4

What gives bones resistance to compression

Answer 4

Impregnation of collagen with crystalline mineral

Question 5

What is crystalline mineral impregnating collagen

Answer 5

Hydroxyapatite

Question 6

2 main types of bone tissue

Answer 6

Woven

Lamellar

Question 7

When can woven bone be seen in adults

Answer 7

Repairing fractures

Question 8

Anatomical breakdown of a long bone

Answer 8

Proximal epiphysis
Metaphysis 
Diaphysis
Metaphysis
Distal epiphysis

Question 9

Describe arrangement of lamellar bone

Answer 9

Outer layer is compact lamellar bone then inner layer consists of interlacing struts of cancellous bone

Question 10

Other names for cancellous bone

Answer 10

Spongy and trabecular

Question 11

Outermost layer to bone

Answer 11

Periosteum

Question 12

Layers to periosteum

Answer 12

Cellular and fibrous

Question 13

Functions of periosteum

Answer 13

Bone repair and growth
Vascular
Good sensory nerve supply

Question 14

Order of development to bone cells

Answer 14

Osteogenic cell-> osteoblast -> osteocyte

Question 15

When does the skeleton start to form

Answer 15

6 weeks into fetal life

Question 16

Name of bone development

Answer 16

Ossification

Question 17

2 types of ossification

Answer 17

Intramembranous

Endochondral

Question 18

Where does intramembranous ossification occur

Answer 18

Existing vascular connective tissue

Question 19

Where does endochondral ossification occur

Answer 19

Existing fetal cartilage models

Question 20

Process of intramembranous ossification

Answer 20

Bone matrix deposited around collagen which mineralises to form woven bone
This woven bone remodels to form lamellar bone

Question 21

Process of endochondral ossification

Answer 21

Cartilage calcifies so chondrocytes die. Periosteal osteoclasts cut channels for sprouting vessels. Osteoblasts enters with vessels to build bone around them

Question 22

Other name for bone matrix

Answer 22

Ostein

Question 23

Problem faced with bone development

Answer 23

When bones are growing they have to support large weights which affect growth at bone terminals

Question 24

Solution to issue of growing bone having to support weights

Answer 24

Shaft ossified from cartilage first then terminals. This growth continues by ossification at growing cartilage plate at metaphysis between them. This ceases once the plate is over run by ossification

Question 25

Age related changes in appearances of bones.

Answer 25

In child’s bones the epiphyses ossify roughly at 24 months but epiphyseal plate remain cartilaginous until after puberty

Question 26

Can bones adapt other than in fractures

Answer 26

Able to grow and adapt its bulk, density and internal and external structure in response to pattern of use

Question 27

What is key to bone growth and repair

Answer 27

It’s large blood supply

Question 28

How does bone grow in diameter

Answer 28

Osteoblasts and osteoclasts create grooves in bone surface whilst expanding then new blood vessels align in them. Osteoblasts build new osteons around vessels

Question 29

How is bleeding important in fracture healing

Answer 29

Haematoma becomes infiltrated by fibrous matrix and invaded by bone progenitors