The heart

Question 1

What type of blood does the right side of the heart pump?

Answer 1

Deoxygenated

Question 2

Where does the right side of the heart pump blood to?

Answer 2

Lungs

Question 3

Where does the left side of the body pump oxygenated blood to?

Answer 3

The whole body

Question 4

Which ventricle of the heart has thicker and more muscular walls? Why?

Answer 4

Left

To help pump the blood around the whole body whereas the right ventricle only has to pump it to the lungs

Question 5

Do the ventricles or the atria have thicker walls? Why?

Answer 5

The ventricles have to push the blood out of the heart whereas the atria just have to pump it within the heart

Question 6

What type of blood does the left side of the heart pump?

Answer 6

Oxygenated

Question 7

What is the purpose of valves?

Answer 7

To maintain a pressure gradient

To prevent the back flow of blood

Question 8

What are the two valves?

Answer 8

Semilunar valves

Atrioventricular valves

Question 9

What is the purpose of the semilunar valves?

Answer 9

Link the ventricles and the pulmonary artery and the aorta

Stop blood flowing back into the heart once the ventricles have contracted

Question 10

What is the purpose of the atrioventricular valves?

Answer 10

Link the atria to the ventricles and stop the blood flowing back into the atria when the ventricles contract

Question 11

What is the purpose of cords?

Answer 11

Attach the atrioventricular valves to the ventricles to stop them being forced up into the atria when the ventricles contract

Question 12

What is systole?

Answer 12

Cardiac contraction

Question 13

What is diastole?

Answer 13

Cardiac relaxation

Question 14

What is the first stage of the cardiac cycle?

Answer 14

• Ventricles relax (diastole)
• Atria contract (systole), decreasing the volume of the chambers and increasing the pressure to push blood into the ventricles

Question 15

What is the second stage of the cardiac cycle?

Answer 15

• Atria relax (diastole)
• Ventricles contract (systole) which increases their pressure
• Pressure becomes higher in the ventricles than the atria, forcing the AV valves shut
• Pressure in the ventricles is also higher than in the aorta and pulmonary artery which opens the SL valves so blood flows out of the arteries

Question 16

What is the third stage of the cardiac cycle?

Answer 16

• Both ventricles and atria relax
• Higher pressure in the arteries cause the SL to close
• Heart starts to fill again with blood
• Pressure in atria increases
• The pressure falls in the ventricles below that of the atria so the AV valves open and blood flows into the ventricles from the atria and the process repeats

Question 17

What are the three summarised stages of the cardiac cycle?

Answer 17

1. Ventricles relax, atria contract
2. Ventricles contract, atria relax
3. Ventricles relax, atria relax

Question 18

What is the equation for calculating cardiac output?

Answer 18

Cardiac output = stroke volume x heart rate

Question 19

What is cardiac output?

Answer 19

Volume of blood pumped by the heart per minute

Question 20

What is heart rate?

Answer 20

The number of beats per minute

Question 21

What is stroke volume?

Answer 21

The volume of blood pumped during each heartbeat

Question 22

What equation do you use to calculate stroke volume?

Answer 22

Stroke volume = cardiac output / heart rate

Question 23

What equation do you use to calculate heart rate?

Answer 23

Heart rate = Cardiac output / stroke volume

Question 24

What are the units for cardiac output?

Answer 24

cm3 min-1

Question 25

What are the units for stroke volume?

Answer 25

cm3

Question 26

What are the units for heart rate?

Answer 26

bpm