The Blood Vessels

Question 1

Arteries

Answer 1

Arteries carry blood away from your heart and to your organs. They stretch as the blood goes through and revert back to the original shape afterwards. They have thick walls containing muscle and elastic fibres.

Question 2

Capillaries

Answer 2

Throughout the body, the capillaries form a huge network of tiny vessels that link arteries to veins. They are very narrow and have thin walls. This enables substances, such as oxygen, to diffuse out of your blood into your cells.

Question 3

Veins

Answer 3

The veins carry blood away form the organs and towards your heart. They have much thinner walls than arteries and they have valves to prevent blood flowing backwards. The valves open for the blood to flow through, but as soon as the blood starts to flow backwards, the valve closes

Question 4

Double circulation

Answer 4

In a double circulatory system, one transport system carries blood from your heart to your lungs and back again. This allows oxygen and carbon dioxide to be exchanged in the lungs

The other transport system carries blood from your heart to all the organs of your body and back again