7.6 Blood vessels and their functions

Question 1

What are arteries?

Answer 1

Arteries carry blood away from the heart and into arterioles.

Question 2

What are arterioles?

Answer 2

Smaller arteries that control blood flow from arteries to capillaries.

Question 3

What are capillaries?

Answer 3

tiny vessels that link arterioles to veins

Question 4

What are veins?

Answer 4

they carry blood from capillaries back to the heart

Question 5

Compare the muscle layer of arteries, arterioles, veins, capillaries

Answer 5

A- Thicker than veins so that constriction and dilation can occur to control volume of blood

Arterioles- thicker than in arteries to help restrict blood flow into the capillaries

V- relatively thin so it cannot control blood flow

C- no muscle layer

Question 6

Compare the elastic layer of arteries, arterioles, veins, capillaries

Answer 6

A- thicker than veins to help maintain blood pressure. The walls can stretch and recoil in response to ht heart beat

Arterioles- thinner than in arteries as the pressure is lower

V- relatively thin as the pressure is much lower

C- no elastic layer

Question 7

Compared the wall thickness of arteries, arterioles, veins, capillaries

Answer 7

A- thicker wall than veins to help prevent the vessels bursting due to high pressure

Arterioles- dinner as pressure is slightly lower

V- thin as the pressure is much lower so there is low risk of bursting. The thinness means the vessels are easily flattened, which helps the flow of blood up to the heart.

C- one cell thick consisting of only a lining layer. This provides a short diffusion distance for exchanging materials between the blood and cells.

Question 8

Which between arteries and veins have valves?

Answer 8

Veins

Question 9

What property of capillaries allows it to maximise diffusion?

Answer 9

Capillaries are 1 cell thick with narrow diameters, meaning red blood cells can only just fit through and are squashed against the walls maximising diffusion as blood flow slows down.