11.1 & 11.2 — The Circulatory System & Heart #
IGCSE Biology | Practice Test | 25 Questions
Give the definition of the circulatory system.
What is meant by the term double circulation?
Name the four chambers of the human heart.
What is the function of the septum in the heart?
Name the two types of valve found in the heart.
What are the coronary arteries, and why are they important to the heart?
State where blood goes after it is pumped out of the left ventricle.
State where blood goes after it is pumped out of the right ventricle.
List three methods that can be used to monitor the activity of the heart.
State two possible risk factors for coronary heart disease.
Explain why the left ventricle has a thicker muscular wall than the right ventricle.
Explain why the walls of the ventricles are thicker than the walls of the atria.
Describe what happens to the atrioventricular (AV) valves and the semilunar valves when the ventricles contract.
A student measures her pulse rate at rest, then again immediately after 3 minutes of jogging.
(a) State the expected result.
(b) Give two reasons why the pulse rate changes in this way.
Explain how the valves in the heart ensure that blood flows in one direction only.
Describe how coronary heart disease develops. Include in your answer what causes the narrowing of the coronary arteries and what effect this has on the heart muscle.
Explain how smoking increases the risk of developing coronary heart disease.
Describe the two circuits that make up the double circulation in humans. For each circuit, state where blood travels, state whether the blood pressure is high or low, and explain why.
Describe the complete path of blood through the heart, starting from when deoxygenated blood enters the right atrium. Include the names of the valves it passes through.
State three lifestyle risk factors for coronary heart disease. Choose one of them and explain how it increases the risk.
The left and right ventricles pump the same volume of blood per beat. However, the blood pressure produced by the left ventricle is much higher than the blood pressure produced by the right ventricle.
(a) Explain why the left ventricle must produce a higher blood pressure than the right ventricle.
(b) Using your knowledge of muscular wall thickness, explain how the heart is adapted to produce this difference in pressure.
(c) Explain why it is important that blood pressure in the circulation to the lungs is kept low.
This question is about one complete heartbeat.
(a) Describe the sequence of events during one heartbeat, starting from when the atria fill with blood.
(b) Explain the role of the atrioventricular (AV) valves during the heartbeat.
(c) Explain the role of the semilunar valves during the heartbeat.
This question is about the double circulation in humans.
(a) Describe the circulation from the heart to the lungs and back. Include where blood travels and what happens to it.
(b) Describe the circulation from the heart to the rest of the body and back. Include where blood travels and what happens to it.
(c) Explain the advantage of having two separate circuits at different pressures, rather than one single circuit around the whole body.
A class is investigating the effect of physical activity on heart rate.
(a) Describe how the class would carry out this investigation. Include what they would measure, what they would change, and what they would keep the same to make it a fair test.
(b) Explain, using your knowledge of what happens in muscles during exercise, why heart rate increases.
(c) Predict what will happen to the student’s heart rate after she stops jogging. Give a reason for your answer.
Coronary heart disease (CHD) is a major cause of death worldwide.
(a) List all the risk factors for CHD as stated in the IGCSE syllabus.
(b) Discuss how diet and exercise can each reduce the risk of developing CHD.
(c) A person finds out they have a genetic predisposition to CHD. Explain why it is still important for this person to maintain a healthy diet and take regular exercise.
