Energy for life: The Heart

Question 1

How does the structure of veins relate to their function? [4 points, excluding explanation]

Answer 1

• transport blood at low pressure
• wide lumen > low resistance to blood flow
• valves > prevent the backflow of blood
• thin muscle layer in wall > contracts to keep blood flowing

Question 2

How does the structure of arteries relate to their function? [3 points, excludin explanation]

Answer 2

• transport blood at high pressure
• thick muscle layer in wall > can contract to maintain pressure
• thick elastic layer in wall > can stretch and recoil to prevent bursting

Question 3

What is the function of the septum?

Answer 3

divides the left and right side of the heart, preventing mixing of oxygenated and deoxygenated blood

Question 4

What factors increase the risk of developing coronary heart disease? List three.

Answer 4

Any from the following list:
- smoking
- diet high in saturated fat and cholesterol,
- lack of exercise
- obesity
- high blood pressure
- high salt levels in diet

Question 5

Why is the left ventricle wall thicker than the right ventricle wall?

Answer 5

to generate a higher pressure on the left side, to push blood round the entire body

Question 6

What is plasma? [2 points]

Answer 6

• yellow liquid
• carries proteins and other subtances like CO2.
• Temperature control

Question 7

What are the function of red blood cells?

Answer 7

They carry oxygen from the lungs to cells int he body.

Question 8

Name an adaptation of red blood cells

Answer 8

no nucleus for larger are to carry haemoglobin