Blood Vessels

Question 1

What are the different types of blood vessels?

Answer 1

• Arteries
• Arterioles
• Capillaries

Question 2

What do the arteries do?

Answer 2

Carry blood away from the heart and into arterioles

Question 3

What are arterioles?

Answer 3

Smaller arteries that control blood from arteries to capillaries

Question 4

What are capillaries?

Answer 4

Tiny vessels that link arterioles to veins

Question 5

What do veins do?

Answer 5

Carry blood from capillaries back to the heart

Question 6

What are the various layers to blood vessels?

Answer 6

• Tough Fibrous Outer Layer
• Muscle Layer
• Elastic Layer
• Thin inner lining ( endothelium )
• Lumen

Question 7

What is the purpose of the tough fibrous outer layer?

Answer 7

Resists pressure changes from both within and outside

Question 8

What is the purpose of the muscle layer?

Answer 8

Contract and so control the flow of blood

Question 9

What is the purpose of the elastic layer?

Answer 9

Helps maintain blood pressure by stretching and springing back ( recoiling )

Question 10

What is the purpose of the endothelium?

Answer 10

Smooth to reduce friction and thin to allow diffusion

Question 11

What is the purpose of the lumen?

Answer 11

Central cavity of the blood vessel through which the blood flows

Question 12

What differs between each blood vessel?

Answer 12

The relative proportions of each layer

Question 13

How do arterioles differ to arteries?

Answer 13

• Smaller in diameter

* Having a relatively larger muscle layer and lumen

Question 14

What are the differences in structure related to?

Answer 14

Differences in the function that each type of vessel performs

Question 15

What is the purpose of the arteries?

Answer 15

To transport blood rapidly under high pressure from he heart to the tissues

Question 16

How is the artery’s structure adapted?

Answer 16

• Muscle layer is thick compared to veins
• Elastic layer is relatively thick compared to veins
• Overall thickness of walls is high
• There are no valves

Question 17

How does a thicker muscle layer benefit arteries?

Answer 17

• Smaller arteries can be constricted and dilated in order to control the volume of blood passing through them

Question 18

How does a thick elastic layer benefit arteries?

Answer 18

• Blood pressure is kept high in arteries, in order to reach extremities of the body
• Elastic wall is stretched at each beat of the heart ( systole )
• Springs back when the heart relaxes ( diastole ) akin to a stretched band
• Stretching and recoil action helps maintain high pressure and smooth pressure surges created by beating of heart

Question 19

How does overall thickness of walls benefit arteries?

Answer 19

Resists vessel bursting under pressure

Question 20

How does having no valves benefit arteries?

Answer 20

• No valves because blood is under constant high pressure due to the heart pumping blood into the arteries
• Tends to not flow backwards, not needed

Question 21

What arteries have valves?

Answer 21

Those leaving the heart