Bone Tissue: Structure and Function

Question 1

What is the function of bone?

Answer 1

Structure
Mobility
Support
Protection for the body
Storehouse for essential minerals

Question 2

Bone as a connective tissue

Answer 2

The matrix contains collagen fibres and ground substance
25% water, 25% Collagen, 50% crystallised mineral salts
hard but brittle

Question 3

Compact osseous tissue

Answer 3

solid hard layer

external layer of bones

Question 4

Spongy osseous tissue

Answer 4

honeycomb network

found in the inner part of the axial skeleton and epiphyses of long bones

Question 5

Compact bone

Answer 5

denser than spongy bone but less flexible

osteon are the concentric rings of calcified matrix surrounding vertically oriented blood vessels

Question 6

Spongy bone

Answer 6

light
lattice like
well organised- gives strength and resisting stress and forces without breaking
osteocytes in lacunae on the surface of the trabeculae
nutrients directly from the blood in the medullary cavities

Question 7

What is remodelling?

Answer 7

removal and replacement at a site

Question 8

Bone development

Answer 8

Embryonic development proceeds from the mesoderm layer
The skull and vertebral column are produced by the intramembranous ossification
As development proceeds down the body axis the long bones of arms and kegs are produced by endochondral ossification

Question 9

What can go Wrong with bone growth?

Answer 9

Low bone density
Osteogenesis imperfecta
apogees disease of the bone
Bone cancer
Bone infections

Question 10

How is blood supplied?

Answer 10

Periosteal parties- periosteum and other osteons of compact bone
Nutrient arteries- medullary cavity and osteons of inner compact bone
Metaphyseal arteries- spongy bone and marrow in this area
Epiphyseal arteries- Spongy bone and marrow in this area

Question 11

What can go wrong with blood supply?

Answer 11

poor cardiac output
osteonecrosis- bone death
inadequate bone growth
bones can receive tenuous blood supply

Question 12

What can remodelling be affected by?

Answer 12

Age
mechanical stress
genetic and environmental levels
hormone levels
calcium and phosphate levels
hormones

Question 13

What are the effects of age?

Answer 13

demineralisation from the age of 40 years- osteopenia
reduces by 1% each year
worse in women 40-45 years
osteoporosis

Question 14

What are the effects of mechanical stress?

Answer 14

weight bearing is important for development and healing
relevant to the weight bearing status of a patinet
Lack of activity results in loss of bone
Weight bearing activity builds bone