Bone

Question 1

Give some functions of bone

Answer 1

Weight bearing and support
Protection of organs
Mineral store
Blood formation - red bone marrow

Question 2

What is the name of the outer membrane of bone?

Answer 2

Periosteum

Question 3

What is the name of the inner membrane of bone?

Answer 3

Endosteum

Question 4

Give some properties of compact bone?

Answer 4

Very organised
Consists of circular structures called osteons.
Lots of pores for blood vessels
Bone matrix called lamellae

Question 5

What is the function of canaliculi and what type of bone is it present in?

Answer 5

Found in compact bone.

Allows the communication between osteocytes.

Question 6

Give some properties of spongy bone?

Answer 6

Less dense
Consists of a network of lamellated trabeculae filled with bone marrow
Porous

Question 7

Give the 6 different types of bone?

Answer 7

Flat bone - front of skull
Sutural - in skull
Short bone - carpal
Irregular bone - vertebra
Long bone - femur 
Sesamoid bone - patella

Question 8

Name the 2 different types of bone formation

Answer 8

Endochondral

Intramembranous

Question 9

Describe the process of endochondral ossification?

Answer 9

Uses a cartilage model to create bone.
Blood vessels invade the cartilage which is eventually replaced with bone.
Cartilage remains in the epiphyseal growth plate.

Question 10

Describe the process of intramembranous ossification?

Answer 10

Mesenchymal cells develop into osteoprogenitor cells that mature into osteoblasts that deposit bone.
No cartilage phase!

Question 11

Which type of bone formation is the most common in long bone growth?

Answer 11

Endochondral

Question 12

What properties do minerals provide bone with?

Answer 12

They make bone stiff and give stupport

They make bone strong especially when under compression

Question 13

What gives bone some flexibility and high strength under tension?

Answer 13

Collagen

Question 14

What are osteoblasts?

Answer 14

Immature bone cells created from osteoprogenitor cells in bone membranes.

Question 15

What is the function of osteoblasts?

Answer 15

They produce the bone matrix and initiate calcification.

Become osteocytes once surrounded by matrix.

Question 16

What are osteocytes?

Answer 16

Mature bone cells found inside lacunae.

Question 17

What is the function of osteocytes?

Answer 17

May maintain bone matrix and sense mechanical forces

Question 18

What are osteoclasts?

Answer 18

Multinucleate cells derived from monocytes/macrophages.

Question 19

What is the function of osteoclasts?

Answer 19

Found on bone surface (ruffled border)

Resorb bone matrix

Question 20

What are the 3 main components of bone extracellular matrix?

Answer 20

Minerals
Protein in form of collagen (type 1)
Water

Question 21

Describe the structure of the extracellular bone matrix?

Answer 21

Strongly cross linked collagen fibres with large gaps for hydroxyapatite crystals

Question 22

What is osteoporosis?

Answer 22

A bone disease where bone resorption is greater than formation resulting in weakened bones.

Question 23

What is osteopetrosis?

Answer 23

Bone disease where resorption of bone is decreased so it becomes dense and stony.

Question 24

What factors control bone mass?

Answer 24

Genes and Environment

Question 25

What else can regulate bone mass?

Answer 25

Mechanical loads