Circulatory System - Blood Vessels

Question 1

State the three types of blood vessel and their functions.

Answer 1

• Arteries - carry oxygenated blood away from the heart
• Capillaries - located in organs where the exchange of substances takes place
• Veins - carry deoxygenated blood to the heart

Question 2

Name the type of blood vessel that branches into capillaries.

Answer 2

Arteries

Question 3

Describe how arteries are adapted to carry out their function.

Answer 3

• They have thick walls, which contain muscle and elastic fibres, that allow them to carry blood at a high pressure
• Artery walls are large compared to the size of their lumen

Question 4

Name the type of blood vessel that joins up to form veins.

Answer 4

Capillaries

Question 5

Describe how capillaries are adapted to carry out their function.

Answer 5

• They have very thin walls, which are 1 cell thick to support the exchange of substances into and out of the blood
• Their walls are permeable, so substances can diffuse in and out

Question 6

Describe how veins are adapted to carry out their function.

Answer 6

• They have valves to prevent the backflow of blood, keeping it flowing in the right direction
• They have a large lumen compared to the width of their walls, helping the blood flow despite low pressure
• They have thin walls as they carry blood at a low pressure