3.1.2 Animal transport – Veins, Arteries and Capillaries

Question 1

List the 5 blood vessels that blood will travel through to get from and to the heart.

Answer 1

Arteries  arterioles  capillaries  venules  veins

Question 2

What is the name of the space inside a blood vessel, which the blood flows through?

Answer 2

The lumen

Question 3

What is the name of the inner layer of cells of a blood vessel and what is its function?

Answer 3

Endothelium – a smooth surface to reduce friction.

Question 4

What is the function of the smooth muscle within a wall of a blood vessel?

Answer 4

• It contracts to allow the blood vessel to constrict and restrict blood flow.
• It relaxes to allow the blood vessel to dilate and increase blood flow.

Question 5

What is the function of the elastic tissue within a wall of a blood vessel?

Answer 5

Allows the stretch and recoil of blood vessels to maintain a high blood pressure.

Question 6

What is the function of the valves?

Answer 6

The valves prevent the backflow of blood.

Question 7

What does the outer most layer of a blood vessel contain to give strength to the vessel?

Answer 7

Collagen

Question 8

What type of blood do arteries carry and in what direction?

Answer 8

High pressure, oxygenated blood away from the heart.

Question 9

How is an artery’s structure related to its function?

Answer 9

• Thick walls – to withstand pressure.
• Small lumen – to maintain pressure.
• Large amount of smooth muscle – to allow for constriction of the blood vessel.
• Smooth endothelium – to reduce friction.
• Large amounts of elastic tissue to stretch and recoil which maintains blood pressure.

Question 10

What type of blood do veins carry and in what direction?

Answer 10

Low pressure, deoxygenated blood towards the heart.

Question 11

How is a vein’s structure related to its function?

Answer 11

• Large lumen – to maximise blood flow
• Thin wall with little elastic tissue/smooth muscle – due to low pressure blood.
• Valves – to prevent the back flow of blood due to the low pressure blood.

Question 12

What do valves work with in order to prevent blood pooling?

Answer 12

The skeletal muscles surrounding the veins.

Question 13

What happens at the capillaries?

Answer 13

Exchange of substances such as oxygen, carbon dioxide, glucose.

Question 14

What is the only cell type that makes up a capillary’s wall?

Answer 14

Endothelial cells.

Question 15

How is a capillary’s structure related to its function?

Answer 15

• Thin, flat endothelial cells reduce the diffusion distance.
• The gaps (fenestrations) between cells allow substance to diffuse through.