Biology (9-1) - 0970 CIE

Heart

Overview

Your heart beats about 70 times a minute, every minute, for your whole life, pushing blood to every organ in your body. It is a muscular pump with four chambers and a set of one-way valves that keep blood flowing in the right direction. Understanding it explains everything from your pulse to the leading cause of death worldwide.

In this lesson you will learn the structure of the mammalian heart, how it is monitored, and what coronary heart disease is. Extended students will explain why the heart's walls differ in thickness, how the valves work in sequence, and why exercise speeds the heart up.

Objectives

Identify in diagrams and images the structures of the mammalian heart, limited to: muscular wall, septum, left and right ventricles, left and right atria, one-way valves and coronary arteries
State that blood is pumped away from the heart in arteries and returns to the heart in veins
State that the activity of the heart may be monitored by: ECG, pulse rate and listening to sounds of valves closing
Investigate and describe the effect of physical activity on the heart rate
Describe coronary heart disease in terms of the blockage of coronary arteries and state the possible risk factors including: diet, lack of exercise, stress, smoking, genetic predisposition, age and sex
Discuss the roles of diet and exercise in reducing the risk of coronary heart disease
[Supplement] Identify in diagrams and images the atrioventricular and semilunar valves in the mammalian heart
[Supplement] Explain the relative thickness of: (a) the muscle walls of the left and right ventricles (b) the muscle walls of the atria compared to those of the ventricles
[Supplement] Explain the importance of the septum in separating oxygenated and deoxygenated blood
[Supplement] Describe the functioning of the heart in terms of the contraction of muscles of the atria and ventricles and the action of the valves
[Supplement] Explain the effect of physical activity on the heart rate

Lesson Note

The heart is the engine of the whole circulatory system, and coronary heart disease is one of the biggest killers in the world. This topic blends pure structure (labelling chambers and valves) with applied biology (diet, exercise and risk), so it rewards both careful recall and clear reasoning.

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Lesson Evaluation

Congratulations on completing the lesson on Heart. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

The thick-walled chambers that pump blood out of the heart are the: A. atria B. ventricles C. valves D. veins Answer: B
The wall of muscle separating the left and right sides of the heart is the: A. septum B. aorta C. valve D. atrium Answer: A
[Supplement] The valves found in the aorta and pulmonary artery are the: A. atrioventricular valves B. semilunar valves C. coronary valves D. venous valves Answer: B
Which is a risk factor for coronary heart disease that cannot be controlled? A. smoking B. diet C. lack of exercise D. age Answer: D
The heart muscle itself is supplied with blood by the: A. pulmonary vein B. coronary arteries C. vena cava D. semilunar valves Answer: B