Heart

Question 1

What do the coronary arteries do?

Answer 1

Carry oxygenated blood

To the heart muscles

Question 2

The rise and fall in blood pressure in the aorta is greater than in the small
arteries. Suggest why?

Answer 2

Linked to right ventricle = high pressure
Lots of elastic tissue
Allows it to stretch

Question 3

Other than causing slow blood flow, explain one advantage of capillaries being
narrow?

Answer 3

Faster diffusion
Short pathway / short distance between blood and outside of capillary
Large surface area (of blood) in contact with walls of capillaries;

Question 4

What factor limits the minimum internal diameter of the lumen of a capillary?

Answer 4

Width / size / diameter of blood cell.

Question 5

The maximum pressure in the left ventricle is higher than the maximum pressure in the
right ventricle. What causes this difference in pressure?

Answer 5

Left ventricle has thicker / more muscle;

Question 6

Use the information to explain how the structures of the walls of arteries, veins and
capillaries are related to their functions.

Answer 6

Artery

1. thickest wall, enabling it to carry blood at high pressure / withstand pressure surges
2. most elastic tissue, which maintains pressure;
3. most muscle which maintains pressure;
4. muscle in wall to control blood flow;

Veins
5. thin wall does not have to withstand high pressure
Larger lumen
Valves

Capillary

6. thin wall, allowing diffusion/exchange;
7. only endothelium present, allowing short diffusion pathway;

All vessels
8. have endothelium that reduces friction;

Question 7

Explain the meaning of the term atheroma.

Answer 7

Fatty substances (+white blood cells) 
In artery wall (under endothelium)

Question 8

Explain why atheroma may lead to a blood clot

Answer 8

Narrows artery

Damages endothelium;