Blood Vessels

Question 1

What is the function of the veins?

Answer 1

Carry deoxygenated blood back to heart from the body.

Question 2

Which vein is the exception?

Answer 2

Pulmonary vein that carries oxygenated blood to heart from lungs

Question 3

What is the structure of veins?

Answer 3

Thin walls with little elastic fibres and muscle tissue. Has large lumen and contains valves.

Question 4

Why do veins have a large lumen?

Answer 4

To allow blood to flow under a low pressure.

Question 5

Why do valves have veins?

Answer 5

To prevent the backflow of blood that is under a low pressure

Question 6

What is the function of the arteries?

Answer 6

They carry oxygenated blood from the heart to the rest of the body.

Question 7

Which artery is the exception?

Answer 7

Pulmonary artery that carries deoxygenated blood to the lungs.

Question 8

Describe the structure of the arteries?

Answer 8

Thick muscular walls containing elastic tissue. Smaller lumen than veins. More collagen and a folded endothelium layer.

Question 9

Why do the arteries have smaller lumen than veins?

Answer 9

To keep the pressure inside the arteries high.

Question 10

Why do arteries not contain valves?

Answer 10

Backflow of blood is unlikely due to the high pressure therefore no need to try and prevent it.

Question 11

How does the structure of muscle in the arteries walls help aid its function?

Answer 11

So the artery can dilate and constrict to change shape. This allows more or less blood to flow.

Question 12

How does collages aid in the function of arteries?

Answer 12

It is strong and helps prevent the artery walls bursting at high pressures.

Question 13

How does elastic tissue help in the function of arteries?

Answer 13

To allow stretch and recoil at high pressures. This forces blood out at higher pressures and keeps the flow constant.

Question 14

What’s the function of the capillaries?

Answer 14

They connect arteries to veins.

Substances like amino acids, glucose and oxygen are exchanged between cells and capillaries by diffusion.

Question 15

What is the fluid called that is squeezed out of capillaries?

Answer 15

Tissue fluid

Question 16

Describe the structure of a capillary?

Answer 16

Thin walls only one cell thick.

Made of endothelium only.

Question 17

How big is the lumen of a capillary compared to arteries and veins?

Answer 17

Extremely small compared to veins and arteries.

Question 18

Are there any valves inside capillaries?

Answer 18

No

Question 19

Why are capillary walls only one cell thick?

Answer 19

To allow easy and efficient diffusion of substances from blood to tissue fluid.

Question 20

Why is blood flow slowed down when it gets to he capillary beds?

Answer 20

To prevent bursting of the capillaries.

To allow efficient gas and substance exchange (slower flow=more diffusion)

Question 21

Name 3 adaptations of capillaries.

Answer 21

• Large SA.
• Total cross sectional area is greater than the arteriole that supplies them.
• Walls are a single endothelial cell thick.

Question 22

What do the capillaries do?

Answer 22

Form a network through all the tissues of the body to provide every cell with the substances they need.

Question 23

Plasma is 55% of the blood. What is it?

Answer 23

A yellow liquid that carries; 
Dissolved glucose
Amino acids
Mineral ions
Hormones
RBCs
WBCs
Platelets

Question 24

What are the three large plasma proteins?

Answer 24

Albumin
Fibrinogen
Globulins

Question 25

What’s the function of albumin?

Answer 25

Maintain osmotic balance

Question 26

What’s the function of fibrinogen?

Answer 26

Blood clotting

Question 27

What’s the function of globulins?

Answer 27

Transport and immunity

Question 28

What are the functions of the blood?

Answer 28

Transport O2 and CO2 to and from cells
Transport digested food from small intestine
Transport nitrogenous waste to excretory organs
Transport chemical messengers and hormones
Transport food from storage compounds to cells
Transport platelets to damaged areas
Transport cells and antibodies involved in immune system.

Question 29

What is lymph?

Answer 29

Tissue fluid that doesn’t return to the blood vessels.

Question 30

What does lymph have less of compared to plasma and tissue fluid?

Answer 30

Oxygen and nutrients

Question 31

What do lymph vessels contain?

Answer 31

Valves to prevent backflow

Question 32

Where does lymph return to the blood?

Answer 32

Through the left subclavian vein under the collar bone.

Question 33

What is the role of the lymphatic system?

Answer 33

To defend the body of foreign bacteria or invading pathogens

Question 34

What is the equation for filtration pressure?

Answer 34

Hydrostatic pressure - oncotic pressure= FP