The Circulatory System

Question 1

What are the 4 components of blood and explain them?

Answer 1

1. Plasma - the straw coloured liquid part of the blood that transports blood cells, hormones, food molecules e.g. glucose, amino acids, minerals, vitamins, urea, carbon dioxide.
2. Red blood cells - have a biconcave shape, contain haemoglobin which carries oxygen and don’t have a nucleus.
3. White blood cells- protect the body against disease by producing antibodies.
4. Platelets- for blood clotting and the formation of scabs. The platelets work by changing soluble fibrinogen into fibrin
   This causes blood clotting and scab formation.

You need to be able to recognise the components of blood in a diagram.

Question 2

What happens when red blood cells are placed in water?

Answer 2

They will take in water by osmosis and burst in a process known as cell lysis.

Question 3

What would you see if cell lysis occurs?

Answer 3

There will be a higher concentration of water.

Question 4

What are the properties of arteries?

Answer 4

Arteries:

Have **thick walls* as

carry blood at high pressure away from the heart and into the organs.

usually carry oxygenated blood and nutrients.

have muscle and elastic fibres and they expand as blood pulses through, after the blood passes through, the arteries return to the normal size to withstand the pressure and bring the blood vessel back into its normal shape after it distends.

Have a smaller lumen than veins.

Question 5

What are the properties of veins?

Answer 5

Veins:

Carry blood back to the heart.

Have valves that prevent the backflow of blood.

usually carry deoxygenated blood, with higher carbon dioxide concentration than arteries.

Have quite thin walls that carry blood at lower pressure.

Have large lumen to prevent friction and to let the blood flow back to the heart.

Question 6

What do capillaries do?

Answer 6

They allow the exchange of material e.g. glucose, amino acids, oxygen and carbon dioxide with the tissues through their permeable walls.

Question 7

What are the blood vessels that enter the heart and explain them?

Answer 7

The vena cava (large vein that carries blood to the heart from other areas of the body) and the pulmonary vein (carries blood from the lungs).

Question 8

What are the blood vessels that leave the heart and explain them?

Answer 8

The aorta (the largest artery of the body that carries blood from the heart to the circulatory system) and the pulmonary artery (carries blood to the lungs).

Question 9

What is the blood vessel that enters the lungs and explain it?

Answer 9

The pulmonary artery (carries blood from the heart).

Question 10

What is the blood vessel that leaves the lungs and explain it?

Answer 10

Pulmonary vein (carries blood to the heart).

Question 11

What is the blood vessel that enters the liver and explain it?

Answer 11

Hepatic artery (carries blood from the aorta).

Question 12

What is the blood vessel that leaves the liver and explain it?

Answer 12

Hepatic vein (carries blood to the vena cava).

Question 13

What blood vessel leaves the small intestine and explain it?

Answer 13

Hepatic portal vein (carries blood to the liver).

Question 14

What blood vessel enters the kidney and explain it?

Answer 14

Renal artery (carries blood from the aorta).

Question 15

What blood vessel leaves the kidney and explain it?

Answer 15

Renal vein (carries blood to the vena cava).

Question 16

What is double circulation?

Answer 16

Blood travels through the heart twice in one complete circuit of the body.

Question 17

What is the heart’s double pump?

Answer 17

1. It pumps blood to the lungs.
2. It pumps blood around the body.

Question 18

Why is each side of the heart kept completely separate?

Answer 18

So that the deoxygenated blood doesn’t mix with the oxygenated blood.

Question 19

What are the 4 chambers of the heart?

Answer 19

The left and right atrium (upper chambers) and the left and right ventricle (the lower chambers).

Question 20

Explain what happens in the right atrium.

Answer 20

The right atrium receives deoxygenated blood from the body through the vena cava.

Question 21

Explain what happens in the right ventricle.

Answer 21

The right ventricle receives blood from the right atrium and pumps it out into the pulmonary artery to the lungs. In the lungs the blood then becomes oxygenated.

Question 22

Explain what happens in the left atrium.

Answer 22

The left atrium receives oxygenated blood from the lungs through the pulmonary vein.

Question 23

Explain what happens in the left ventricle.

Answer 23

The left ventricle receives oxygenated blood from the left atrium and pumps it out into the aorta and then around the body.

Question 24

What does exercise do to your heart overtime?

Answer 24

It strengthens the heart muscle which means that it is under less strain when it has to work hard as less effort will enable the heart to pump large amounts of blood per beat.

Question 25

What does exercise make your body do?

Answer 25

Exercise causes increased muscle contraction.

Muscle cells carry out more respiration.

Therefore muscle cells require more oxygen.

Therefore the heart must beat faster to supply oxygen to the cells.