Circulatory Systems and Aids

Question 1

What is the first circulatory system?

Answer 1

1. Deoxygenated blood to lungs - take in oxygen

2. Oxygenated blood to heart

Question 2

What is the second circulatory system?

Answer 2

1. Oxygenated blood to organs - use up oxygen

2. Deoxygenated blood to heart

Question 3

What are the walls of the heart mainly made up of?

Answer 3

Muscular tissue.

Question 4

What do the valves in the heart do?

Answer 4

Prevent blood flowing backwards.

Question 5

How does the heart pump?

Answer 5

1. Blood flows into atria from vena cava and pulmonary vein
2. Atria contract, blood pushed into ventricles
3. Ventricles contract, blood pushed out of pulmonary artery and aorta
4. Blood leaves heart

Question 6

What are the three types of blood vessel?

Answer 6

1. Arteries
2. Capillaries
3. Veins

Question 7

What do arteries do?

Answer 7

Carry blood from the heart.

Question 8

What do capillaries do?

Answer 8

Supply food and oxygen, taking away CO2.

Question 9

What do veins do?

Answer 9

Carry blood to heart.

Question 10

Why do arteries need to be strong and elastic?

Answer 10

They pump blood out at high pressure.

Question 11

Why are arteries strong and elastic?

Answer 11

1. Layers of muscle for strength

2. Elastic fibres for elasticity

Question 12

How big are artery lumens?

Answer 12

Small compared to wall thickness.

Question 13

How big are capillaries?

Answer 13

Too small to see.

Question 14

How are capillaries well-adapted?

Answer 14

Very thin walls to decrease distance.

Question 15

What to capillaries join up to form?

Answer 15

Veins.

Question 16

Why don’t veins have thick walls?

Answer 16

The blood is at a lower pressure.

Question 17

Why do veins have a bigger lumen?

Answer 17

To keep the blood flowing despite lower pressure.

Question 18

What do veins have that arteries don’t?

Answer 18

Valves.

Question 19

What are the four things in blood?

Answer 19

1. Red blood cells
2. White blood cells
3. Plasma
4. Platelets

Question 20

What do red blood cells do?

Answer 20

Carry oxygen from the lungs to all cells in the body.

Question 21

How are red blood cells well adapted?

Answer 21

1. No nucleus, more space for oxygen

2. Biconcave shape for larger surface area

Question 22

What is haemoglobin?

Answer 22

Red pigment that combines with oxygen to form oxyhaemoglobin.

Question 23

What happens to oxyhaemoglobin in body tissues?

Answer 23

Splits up into oxygen and haemoglobin.

Question 24

What do white blood cells do?

Answer 24

1. Engulf pathogens
2. Produce antibodies
3. Produce antitoxins

Question 25

What are platelets?

Answer 25

Small cell fragments.

Question 26

What do platelets do?

Answer 26

Clot at wounds, stopping blood pouring out.

Question 27

What does plasma carry?

Answer 27

1. RBC, WBC and platelets
2. Nutrients - glucose and amino acids
3. Carbon dioxide
4. Urea
5. Hormones
6. Antibodies and antitoxins

Question 28

What would an ideal artificial blood product do?

Answer 28

Replace the function of red blood cells so blood transfusions aren’t needed.

Question 29

What are artificial hearts?

Answer 29

Mechanical devices used to pump blood.

Question 30

What is the advantage of artificial hearts?

Answer 30

Not rejected by immune system.

Question 31

What are the problems with artificial hearts?

Answer 31

1. Surgery (infection)
2. Doesn’t work as well (motor)
3. Blood clots or strokes
4. Blood thinning drugs (accidents)

Question 32

What are the problems with replacing heart valves?

Answer 32

1. Major surgery

2. Blood clots

Question 33

What is coronary heart disease?

Answer 33

Where the arteries that supply the blood to the muscle of the heart get blocked by fatty deposits.

Question 34

What do stents do?

Answer 34

Keep arteries open so blood can pass through.

Question 35

What are the problems with stents?

Answer 35

1. The stents can irritate the artery - scar tissue

2. Blood thinning drugs are needed