Bones

Question 1

Periosteum

Answer 1

Outer layer of bones, fibrous layer serves as a point for blood vessels and nerves to attach, cellular layer contains mesenchymal stem cells

Question 2

Osteoblasts

Answer 2

Synthesises osteoid and then deposits calcium hydroxyapatite to form extracellular matrix of bone

Question 3

Osteocytes

Answer 3

Osteoblasts that got stuck in the bone, monitor the bone, respond to stress levels

Question 4

Osteoclasts

Answer 4

Destroyers, perform resorption (destruction)

Question 5

Osteoid

Answer 5

Extracellular matrix, mostly type 1 collagen stuck together by ground substance

Question 6

Osteon

Answer 6

Functional unit of compact bone, circular structure

Question 7

Structure of osteon

Answer 7

Layers of rings called lamellae separated by interstitial lamella

Question 8

Haversian canal

Answer 8

Blood vessels in the centre of osteon

Question 9

Volkmann canal

Answer 9

Connect Haversian canals with periosteum

Question 10

Endochondral ossification

Answer 10

Formation of long bones from cartilage template, continued lengthening is by ossification at epiphyseal plates

Question 11

Intramembranous ossification

Answer 11

Form from clusters of mesenchymal stem cell in the centre of the bone

Question 12

Cancellous bone conversion to cortical bone

Answer 12

1. mesenchymal stem cells differentiate into osteoblasts, lay down osteoid
2. Osteoblasts is trapped
3. Repeat to form lamellae
4. Central MSCs convert into blood vessels, lymph vessels and nerves

Question 13

Appositional growth

Answer 13

increasing width

Question 14

5 types of bones

Answer 14

Long, short, flat, irregular, sesamoid

Question 15

Long bones

Answer 15

• Longer than they are wide
• Support the weight of the body and facilitate movement

Question 16

Short bones

Answer 16

• Approximately as long as they are wide
• Provide stability and some movement

Question 17

Flat bones

Answer 17

• Somewhat flattened with roughly parallel opposite edges
• Protect internal organs and provide large areas of attachment for muscles

Question 18

Irregular bones

Answer 18

• Vary in shape and structure and do not fit any other category
• Protect internal organs, provide anchor points for muscle groups

Question 19

Sesamoid bones

Answer 19

• Small, round bones found in tendons of hands, knees and feet
• Protect tendons from stress and damage from repeated “wear and tear”

Question 20

Where is bone marrow found?

Answer 20

In spaces in cancellous bone along with blood vessels and nerves

Question 21

Trebeculae in cancellous bone

Answer 21

Supporting beams in bone

Question 22

Red bone marrow

Answer 22

Full of developing RBC, rich blood supply, only found in cancellous bone.

Question 23

Function of red bone marrow

Answer 23

Replenish cells in blood (haemopoiesis)

Question 24

Yellow bone marrow

Answer 24

Full of adipocytes, poor blood supply

Question 25

Function of yellow bone marrow

Answer 25

Shock absorber and energy source, can convert to red bone marrow

Question 26

Precapillary sphincters

Answer 26

Control flow in capillaries, located between arterials and capillaries

Question 27

3 layers of veins

Answer 27

Tunica intima (endothelial), tunica media (elastic fibres and smooth muscle cells), tunica externa (elastic fibrous capsule)

Question 28

Systemic veins

Answer 28

Return deoxygenated blood back to right atrium

Question 29

Superficial veins

Answer 29

Located close to the skin, no corresponding artery

Question 30

Deep veins

Answer 30

Located deep between tissues and typically located near a corresponding artery with same name

Question 31

Tunica intima in arteries

Answer 31

composed of an elastic lining and smooth endothelium

Question 32

Tunica media

Answer 32

composed of smooth muscle and elastic fibres, thicker in arteries

Question 33

Tunica adventitia

Answer 33

Strong outer covering composed of collagen and elastic fibres, allows arteries to stretch but prevents over-expansion

Question 34

Collateral circulation

Answer 34

Collateral vessels provide an alternative route, like a road diversion