ORGANISATION PART B

Question 1

Do arteries carry low pressure blood or high pressure blood to from the ? To the ?

Answer 1

Arteries carry high pressure blood from the heart to the organs in the body

Question 2

Describe the structure of arteries

Answer 2

Arteries have very thick, muscular walls which allows them to withstand the very high pressure of the blood. Blood travels through the arteries in surges every time the heart beats. Elastic fibres stretch when the surge of blood passes through and then recoil in between surges, which keeps the blood moving.

Question 3

Do arteries carry blood away or towards the heart?

Answer 3

Away

Question 4

In most arteries, what is the blood like?

Answer 4

The blood is bright red and oxygenated

Question 5

Describe the structure of the capillaries

Answer 5

They have very thin walls so the diffusion path is very short. This allows substance to diffuse rapidly between the blood and the body cells.

Question 6

What happens when the blood passes through capillaries?

Answer 6

When the blood passes through the capillaries, substances such as glucose and oxygen diffuse from the blood to the cells. Carbon dioxide diffuses from the cells back to the blood. Once the blood has passed through the organs, it now makes its way back to the heart in veins.

Question 7

Describe the structure of the veins

Answer 7

Veins carry blood towards the heart. In most veins, the blood is deep purple red and deoxygenated. No pulse. They have valves which prevent the back flow of blood. When blood is flowing in the right direction, the valves open. They are closed otherwise. They have much thinner walls as they have a much lower pressure

Question 8

The capillaries provide a massive surface area and thin walls for easy ?

Answer 8

Diffusion

Question 9

Where do we find arteries in the body?

Answer 9

Arteries are relatively near the surface mostly. Also known as your pulse