The heart and circulation

The heart is an organ that pumps blood around the body.

Figure 10 is a model of the heart and shows the direction of blood flow.

Draw one line from each blood vessel shown in Figure 10 to the name of the blood vessel.

Heart rate is controlled by a group of cells.

The group of cells acts as a pacemaker.

Where would the pacemaker be located in Figure 10 ?

Tick () one box.

Heart muscle cells contain many mitochondria.

Explain why heart muscle cells contain many mitochondria.

A small number of people are born with a ‘hole in the heart’.

Figure 11 shows the position of a hole in the heart.

The hole allows some blood from the right side of the heart to mix with blood in the left side of the heart.

Suggest two symptoms of having a hole in the heart.

In an operation to repair a hole in the heart:

• a flexible tube is inserted into a blood vessel and guided to the heart

• a mesh patch is passed down the tube

• the mesh patch covers the hole.

Heart tissue grows around the mesh and closes the hole.

Suggest two possible risks of this operation to repair a hole in the heart.

The heart is an organ that pumps blood around the body.

Figure 1 is a model of the heart and shows the direction of blood flow.

Draw one line from each blood vessel shown in Figure 1 to the name of the blood vessel.

Heart rate is controlled by a group of cells.

The group of cells acts as a pacemaker.

Where would the pacemaker be located in Figure 1 ?

Tick () one box.

Heart muscle cells contain many mitochondria.

Explain why heart muscle cells contain many mitochondria.

A small number of people are born with a ‘hole in the heart’.

Figure 2 shows the position of a hole in the heart.

The hole allows some blood from the right side of the heart to mix with blood in the left side of the heart.

Suggest two symptoms of having a hole in the heart.

In an operation to repair a hole in the heart:

• a flexible tube is inserted into a blood vessel and guided to the heart

• a mesh patch is passed down the tube

• the mesh patch covers the hole.

Heart tissue grows around the mesh and closes the hole.

Suggest two possible risks of this operation to repair a hole in the heart.

Figure 6 shows a human heart.

The vena cava carries blood into the heart from the body.

Which blood vessel in Figure 6 is the vena cava?

Tick (✓) one box.

Which chamber of the heart pumps blood to the body?

Tick (✓) one box.

What is the name of the blood vessel that carries blood to the heart muscle?

Tick (✓) one box.

The heart and some blood vessels contain valves.

Which type of blood vessel has valves?

Tick (✓) one box.

What is the function of valves?

Figure 7 shows a blood capillary.

Explain one way the capillary is adapted for its function.

Table 2 shows information about the blood of four people.

Person W has 5 000 000 red blood cells in 1 mm³ of blood.

What is 5 000 000 written in standard form?

Tick (✓) one box.

Draw one line from each description to the person in Table 2 it describes.

Description
Person in Table 2

The greater the height above sea level, the less oxygen there is in the air.

People who live high above sea level have more red blood cells than people who live at sea level.

Some athletes train in mountains high above sea level.

Explain why having more red blood cells will improve an athlete’s performance.

Figure 8 shows the human breathing system.

Name parts A and B.

Choose answers from the box.

Where does gas exchange happen in the breathing system?

Tick (✓) one box.

Give two ways that the lungs are adapted for efficient gas exchange.

Table 3 shows the percentage of gases in air breathed into the lungs and air breathed out of the lungs.

Explain the differences in the air breathed into the lungs and the air breathed out of the lungs.

The percentages given in each column of Table 3 do not add up to 100%.

Suggest one reason why.

The circulatory system includes the heart, blood vessels and blood.

The heart pumps the blood in a double circulatory system.

Describe what is meant by a ‘double circulatory system’.

Heart rate is controlled by a group of cells that act as a pacemaker.

Where in the heart is the pacemaker found?

Which blood vessel carries deoxygenated blood?

Tick (✓) one box.

The structure of a vein is different from the structure of an artery.

One difference is that veins have valves but arteries do not have valves.

Explain why veins have valves, but arteries do not.

Describe two structural differences between a vein and an artery.

Do not refer to valves in your answer.

This question is about the heart.

Why is the heart described as an organ?

Valves in the heart keep the blood flowing through the heart in one direction. Figure 11 shows the heart with one of the valves labelled.

Explain the effects on a person if the valve labelled in Figure 11 developed a leak.

Faulty heart valves can be replaced using biological or mechanical valves. The faulty valve is replaced during an operation. Biological valves:

• are from animals or human donors

• allow blood to flow through them normally

• wear out and stiffen over time, so may need to be replaced.

Mechanical valves:

• are made from synthetic materials

• may cause blood clots on the surface of the valve

• require anti-clotting drugs to be taken for the rest of the patient’s life

• can last for a very long time in ideal conditions.

A young woman enjoys extreme sports and would like to start a family. The woman needs a heart valve replacing.

Describe the advantages and disadvantages for this young woman of having a biological heart valve instead of a mechanical heart valve.

Figure 5 shows the human heart.

Which blood vessel transports blood with the highest oxygen concentration into the heart? Tick (✓) one box.

Blood pressure is a measure of the force of the blood against the walls of the blood vessels. Which blood vessel transports blood at the highest pressure? Tick (✓) one box.

What is the correct order for blood flowing through the heart to the lungs? Tick (✓) one box.

Every year thousands of people in the UK have heart attacks.

A heart attack is caused when the heart muscle cells do not get enough oxygen, causing the cells to die.

Statins and stents are two treatments used to reduce the risk of someone having a heart attack. Evaluate the use of statins compared with the use of a stent to reduce the risk of a heart attack.

Many people who survive a heart attack get out of breath easily when they exercise gently. Explain why heart attack survivors get out of breath easily.

Scientists have developed patches of beating heart cells to repair damaged

heart tissue. The patches are placed onto areas of the heart where cells have died. New cells grow to replace the dead cells. The patches are made using a person’s own cells that are converted into stem cells.

Explain why stem cells are used to make the patches.

The scientists could have used human embryonic stem cells to make the patches. Give two advantages of using stem cells made from the person’s own cells, rather than using embryonic stem cells.

Being overweight can affect the health and life expectancy of a person.

What is one lifestyle change a person could make to help them lose body mass? Tick (✓) one box.

Exercise has many health benefits. Give two health benefits of regular exercise. Do not refer to losing body mass in your answer.

During exercise, breathing rate increases to provide more oxygen for aerobic respiration.

What is the equation for aerobic respiration? Tick (✓) one box.

Figure 1 shows the human breathing system.

Where does gas exchange take place? Tick (✓) one box.

A scientist investigated the effect of exercise on the breathing rate of four people. This is the method used.

1. Measure the resting breathing rate.

2. Exercise for 10 minutes.

3. Measure the breathing rate as soon as exercise stops.

4. Record the time taken for the breathing rate to return to the resting rate.

Table 1 shows the results.

The scientist concluded that person B was the fittest. Give two reasons that support the scientist’s conclusion. Use Table 1.

Suggest two reasons why the scientist’s conclusion may not be valid.

Give two changes that happen in the body during aerobic exercise. Do not refer to increased breathing rate in your answer.

Muscles respire anaerobically during vigorous exercise. Complete the sentences. Choose answers from the box.

Muscles respire anaerobically if they do not have

Anaerobic respiration of glucose produces.

Starch is digested to form sugar molecules in the digestive system.

What is the name of the enzyme that digests starch?

Where are most food molecules absorbed? Tick (✓) one box.

Figure 6 shows two villi. Figure 6 also shows one cell on the surface of a villus as seen using an electron microscope.

Give one advantage of using an electron microscope compared with using a light microscope.

What type of blood vessel is labelled X ? Tick (✓) one box.

The real length of one villus is 0.8 mm Calculate the image length if the villus is viewed at a magnification of ×20 Use the equation:

Figure 7 shows two cells from the surface of a villus. There are sugar molecules inside and next to each cell.

Name the process by which sugar moves into cell A.

Name the process by which sugar moves into cell B.

Give one use of sugar in the body.

Figure 6 is repeated below.

Explain how villi are adapted for efficient absorption of sugar molecules.

Starch is digested to form sugar molecules in the digestive system.

What is the name of the enzyme that digests starch?

Where are most food molecules absorbed? Tick (✓) one box.

Figure 2 shows two villi. Figure 2 also shows one cell on the surface of a villus as seen using an electron microscope.

Give one advantage of using an electron microscope compared with using a light microscope.

What type of blood vessel is labelled X ? Tick (✓) one box.

The real length of one villus is 0.8 mm Calculate the image length if the villus is viewed at a magnification of ×20 Use the equation:

Figure 3 shows two cells from the surface of a villus. There are sugar molecules inside and next to each cell.

Name the process by which sugar moves into cell A.

Name the process by which sugar moves into cell B.

Give one use of sugar in the body.

Figure 2 is repeated below.

Explain how villi are adapted for efficient absorption of sugar molecules.

Figure 10 shows a human heart.

Which blood vessel carries deoxygenated blood away from the heart to the lungs?

Tick (✓) one box.

The natural resting heart rate is controlled by a group of cells that act as a pacemaker.

Where in the heart are ‘pacemaker cells’ found?

Tick (✓) one box.

Some people may be treated with a drug to slow their heart rate.

Digitalis is a drug that slows the heart rate.

Where does the drug digitalis originate from?

Tick (✓) one box.

Beta blockers are another type of drug that slows the heart rate.

Table 2 shows information for people who do not take beta blockers and for people who do take beta blockers.

• Stroke volume is the volume of blood pumped out of the heart each time it beats.

• Cardiac output is the total volume of blood pumped out of the heart each minute.

Calculate stroke volume X in Table 2.

Use the equation: cardiac output = stroke volume × heart rate

Give your answer to 2 significant figures.

Some people who take beta blockers get out of breath when they exercise.

Explain why beta blockers can have this effect during exercise.

You should refer to information given in Table 2.

Figure 1 shows a human heart.

Which blood vessel carries deoxygenated blood away from the heart to the lungs? Tick (✓) one box.

The natural resting heart rate is controlled by a group of cells that act as a pacemaker. Where in the heart are ‘pacemaker cells’ found?

Tick (✓) one box.

Some people may be treated with a drug to slow their heart rate.

Digitalis is a drug that slows the heart rate. Where does the drug digitalis originate from?

Tick (✓) one box.

Beta blockers are another type of drug that slows the heart rate. Table 1 shows information for people who do not take beta blockers and for people who do take beta blockers.

• Stroke volume is the volume of blood pumped out of the heart each time it beats.

• Cardiac output is the total volume of blood pumped out of the heart each minute.

Calculate stroke volume X in Table 1. Use the equation: cardiac output = stroke volume × heart rate Give your answer to 2 significant figures.

Some people who take beta blockers get out of breath when they exercise. Explain why beta blockers can have this effect during exercise. You should refer to information given in Table 1.

Exercise can improve health.

A student measured her breathing rate at rest, when walking and when jogging.

Figure 8 shows her results.

Compare the breathing rates when doing the three different activities.

Use values from Figure 8 in your answer.

Explain why the breathing rate changes when doing different activities.

Figure 9 shows the heart in the circulatory system.

The heart is a double pump.

Describe what this means.

Use Figure 9 to help you.

The wall of the left ventricle is much thicker than the wall of the right ventricle.

Suggest one reason for this.

People are encouraged to exercise after recovering from a heart attack.

Suggest one reason why.