DONE Bone

Question 1

What bones do endochondral ossification form?

Answer 1

Long bones from cartilage template

Question 2

What bone type does intramembranous ossification form?

Answer 2

Flat bones with mesenchymal tissue (not hyaline cartilage replacement)

Question 3

What are the 5 stages of fracture repair?

Answer 3

Fracture, haematoma formation, fibrocartilaginous callus formation, bony callus formation, bone remodelling

Question 4

What do osteoclasts do?

Answer 4

Bone breakdown (resorption)

Question 5

What do osteoblasts do?

Answer 5

Bone forming cells, deposit bony matrix

Question 6

What are osteocytes?

Answer 6

Mature osteoblasts, completely surrounded by bony matrix

Question 7

Other name for osteogenesis imperfecta

Answer 7

Brittle bone disease (mutation in COL1A gene, incorrect production of collagen 1 fibres)

Question 8

What is rickets?

Answer 8

Vit. D deficiency causes poor calcium mobilisation, ineffective mineralisation of osteoid

Question 9

Rickets symptoms

Answer 9

Weakened bone, soft bone, short stature, bow-legged appearance

Question 10

Primary type 1 osteoporosis

Answer 10

Postmenopausal, increased osteoclasts (degrade trabecular bone = holes) due to oestrogen loss

Question 11

Primary type 2 osteoporosis

Answer 11

Older people, loss of oestrogen and androgen = loss of osteoblast function

Question 12

Secondary osteoporosis

Answer 12

Drug therapy/space travel/malnutrition

Question 13

Modifiable osteoporosis risk factors

Answer 13

700mg/day of calcium
More exercise (less bone lost due to immobilisation)
Not smoking in women

Question 14

Achondroplasia

Answer 14

Short limb dwarfism (mutation in FGF3 gene), affects collagen formation = endochondral ossification affects long bones

Question 15

What are the 5 types of bone?

Answer 15

Long
Short
Flat
Irregular
Sesmasoid

Question 16

Long bones

Answer 16

Longer > wide
E.g. femur, humerus
In appendicular skeleton
Support weight of body + facilitate movement

Question 17

Short bones

Answer 17

Long = wide
E.g. wrist + ankle joints
Stability + movement

Question 18

Flat bones

Answer 18

Thin, broad surfaces
E.g. ribs, sternum, skull
Protect internal organs + attachment for muscle

Question 19

Irregular

Answer 19

Irregular shape/size
E.g. vertebral column, pelvic bones, patella
Protect internal organs + attachment of muscles

Question 20

Sesmasoid

Answer 20

Embedded in tendons
E.g. patella
Protect tendons from stress + damage

Question 21

Cancellous bone

Answer 21

Spongy bone

Form network of fine bony columns, spaces filled by bone marrow

Question 22

Compact bone

Answer 22

Cortical bone, external surface of bone