The Circulatory System

Question 1

What important substances does plasma carry around the body?

Answer 1

• dissolved food substances such as glucose
• carbon dioxide from the tissues to the lungs
• hormones, from the glands where they are made to their target cells
• plasma proteins such as antibodies
• waste substances such as urea

Question 2

Why does being small mean red blood blood have adapted to their function of carrying oxygen?

Answer 2

They can pass through the smallest blood vessels

Question 3

What are red blood cells shaped like and why does this mean they are better adapted to carrying oxygen?

Answer 3

They are shaped like biconcave discs so they have a large surface area to exchange oxygen quicker

Question 4

What in the red blood cells combines with the oxygen?

Answer 4

The haemoglobin - which also makes them appear red

Question 5

Why don’t red blood cells have a nucleus?

Answer 5

So more haemoglobin can fit in and combine with more oxygen

Question 6

What happens when the haemoglobin reacts with the oxygen in the lungs?

Answer 6

Upon reacting, the oxygen and haemoglobin forms oxyhaemoglobin

Question 7

What happens when the oxyhaemoglobin reaches the tissues?

Answer 7

The reaction is reversible; when the oxyhaemoglobin reaches the tissues, the oxygen is released

Question 8

What does the biconcave shape of the red blood cells provide?

Answer 8

A larger surface area to volume ratio to exchange oxygen more quickly

Question 9

What is the job of the artery?

Answer 9

Arteries transport blood away from the heart to the tissues

Question 10

What is the job of the veins?

Answer 10

The veins transport the blood back to the heart from the tissues

Question 11

What is the job of the capillaries?

Answer 11

The capillaries link the arteries to veins and allow materials to pass between the blood and the tissues

Question 12

What is the the structure of the artery and why is it adapted to its function?

Answer 12

Arteries have a thick, muscular and elastic wall to resist the high pressure

Question 13

What is the structure of the vein and how is adapted to its function?

Answer 13

Veins have a large lumen and valves to try and keep the blood moving back to the heart because the pressure is low

Question 14

What is the structure of the capillaries and how is it adapted to its function?

Answer 14

Capillaries have permeable walls so substances can be transferred between the blood and the tissues

Question 15

What do the left and right atria revieve?

Answer 15

Blood from the veins
•the right atrium recieves deoxygenated blood from the body through the vena cava and the left atrium recieves oxygenated blood from the lungs through the pulmonary vein

Question 16

What do the left and right ventricles do?

Answer 16

Pump blood out into into the arteries
•the right ventricle pumps deoxygenated blood to the lungs through the pulmonary artery and the left ventricle pumps oxygenated blood to the body through the aorta

Question 17

What prevents the backflow of blood throughout the circulation of blood through the heart?

Answer 17

The semilunar (prevents backflow of deoxygenated blood through the pulmonary vein)
The tricuspid valve (prevents backflow back into the right atrium)
The bicuspid valve (prevents backflow back into the left atrium)

Question 18

What are the main veins carrying blood back to the heart?

Answer 18

The pulmonary vein (left side)
Vena cava (right side)

Question 19

What carries blood away from the heart?

Answer 19

The aorta (left side)
The pulmonary artery (right side)

Question 20

Why does the left ventricle wall have a thicker muscle wall to than the right ventricle?

Answer 20

Because it had to pump blood all around the body rather than just too the lungs, which are close by

Question 21

What is a double circulatory system and what does it mean?

Answer 21

The blood is pumped to the lungs and is returned to the heart to be pumped to the body.
This means the blood is at a higher pressure and so flows to the tissues at a faster rate

Question 22

Which side of the heart contains the deoxygenated blood and which side contains the oxygenated?

Answer 22

The right side of the heart (left side when looking on paper) contains the deoxygenated blood and the left side (right side when looking on paper) contains the oxygenated blood

Question 23

What is the liquid part of the blood called?

Answer 23

Plasma