The shape of the lesson
By the end of the lesson, learners can
- Chambers, valves and the septum: Click each part of the cut-away heart, then press Play heartbeats.
- Monitoring the heart and exercise: Choose resting, walking, jogging or sprinting and watch the ECG trace, the heart rate readout and the graph of heart rate against time.
- Coronary heart disease: Pick some risk factors, then press Run 40 years.
- Away in arteries, back in veins: aorta and pulmonary artery leave the ventricles; vena cava and pulmonary vein enter the atria.
- Left side is on the right of a heart diagram; find the thick left ventricle wall.
- Extended valves: AV valves shut when the ventricles contract (lub); semilunar valves shut when they relax (dub).
- Exercise: more respiration, more oxygen and glucose needed, more carbon dioxide to remove, so a faster heart rate.
One picture every idea returns to
The heart is a muscular pump with a muscular wall, a septum, left and right atria, left and right ventricles, one-way valves and coronary arteries that supply its own muscle. Blood is pumped away from the heart in arteries and returns to the heart in veins. Heart activity can be monitored by an ECG, the pulse rate and listening to the sounds of the valves closing. Blockage of the coronary arteries causes coronary heart disease.
Forty-five minutes, phase by phase
| Time | Phase | What happens in the room | Grouping |
|---|---|---|---|
| 0 to 5 min | Hook: predict | Open with the question in the title, Four chambers, four valves, one beat.. The heart is a double pump made of muscle. Put the figure on the board: it is the one picture every idea in the lesson returns to. | Whole class, then pairs |
| 5 to 13 min | Teach and check: Chambers, valves and the septum | Click each part of the cut-away heart, then press Play heartbeats. Project tab 2 of the lab (The heart: parts and heartbeat) and let a student drive it while the class predicts. | Whole class, then pairs |
| 13 to 21 min | Teach and check: Monitoring the heart and exercise | Choose resting, walking, jogging or sprinting and watch the ECG trace, the heart rate readout and the graph of heart rate against time. Project tab 3 of the lab (Heart rate and exercise) and let a student drive it while the class predicts. | Pairs |
| 21 to 30 min | Teach and check: Coronary heart disease | Pick some risk factors, then press Run 40 years. Project tab 4 of the lab (Coronary heart disease and risk factors) and let a student drive it while the class predicts. | Anticipation / Reaction Guide |
| 30 to 36 min | Check | The four Stage 1 questions from the student lesson, answered on mini whiteboards or by show of fingers. Re-teach the one most get wrong. | Individual, then whole class |
| 36 to 43 min | Plenary | The exam-style questions from Stage 2, one at a time: thirty seconds alone, then a random call. The feedback lines in the key give the examiner's wording. | Individual, random call |
| 43 to 45 min | Exit and homework | Set the worksheet below (6 questions, 25 marks). Learners self-assess against the objectives before they leave. | Individual |
Protect the parts that carry the learning
The sequence carries about fifty minutes of material, so the lab is driven by one student while the class predicts rather than explored freely. Times are a guide.
Protected: the check at 30 minutes. It is the only individual read on whether the key idea landed, and it is not cut.
Cut first if the build overruns: the last check in Coronary heart disease, never the check or the plenary.
In a 60 minute block: run worksheet questions 1 to 3 in class as a Rally Coach set and model both the hardest worked example and its check live.
Anticipation / Reaction Guide
Before the lesson, students mark five statements true or false. After the teaching they mark them again and justify any change of mind in one sentence each. The statements come from the examiner traps below.
The full structure, with its variations and the other twelve, is on the cooperative-learning page.
What to head off, and how
| Trap learners fall into | Teaching move that pre-empts it |
|---|---|
| Diagrams show the heart as if you are facing the person, so the left ventricle is on the right of the page. | Find the thick-walled ventricle or the aorta first, then label left and right. |
| Do not write that the heart beats faster "to give the muscles more energy" or "to make more oxygen". | Blood delivers oxygen and glucose faster so the muscle cells can release more energy by respiration. |
| Coronary arteries carry blood to the heart muscle, not blood through the chambers. | The heart cannot use the blood inside its chambers for its own oxygen supply, which is why a blocked coronary artery is so serious. |
The heart: worksheet
6 questions, 25 marks. Written in the style of the papers; no past paper question is reproduced.
Name the blood vessel that (a) brings blood from the body to the heart, (b) carries blood from the heart to the lungs, (c) carries blood from the heart to the body, (d) supplies the heart muscle itself.
Extended. Explain the difference in the thickness of the muscle walls of (a) the left and right ventricles, (b) the atria and the ventricles.
Extended. Describe how the contraction of the heart muscles and the action of the valves move blood through the left side of the heart.
A student measured her pulse rate before and after running for 2 minutes.
| Time | Pulse rate / beats per minute |
|---|---|
| at rest | 68 |
| 0 min after running | 148 |
| 2 min after | 112 |
| 4 min after | 84 |
| 6 min after | 70 |
(a) Calculate the increase in pulse rate caused by the run. (b) Describe the pattern after the run. (c) State two ways to make the results more reliable.
Extended. Explain why the heart rate increases during physical activity.
Describe coronary heart disease, name two risk factors that cannot be changed, and discuss how diet and exercise can reduce the risk.
Answer key and marking notes
- (a) vena cava.
- (b) pulmonary artery.
- (c) aorta.
- (d) coronary artery.
- (a) The left ventricle wall is thicker because it pumps blood all round the body, against more resistance, so it must produce a higher pressure.
- The right ventricle pumps blood only to the lungs, which are close by; a lower pressure also avoids damaging the delicate lung capillaries.
- (b) The atria have thinner walls because they only pump blood a short distance, into the ventricles below.
- The ventricles must pump blood out of the heart into the arteries, so they need thicker, more muscular walls.
- The left atrium contracts, pushing blood through the open atrioventricular valve into the left ventricle.
- The left ventricle contracts; the rise in pressure shuts the atrioventricular valve, preventing backflow into the atrium.
- The semilunar valve at the base of the aorta is pushed open and blood is forced into the aorta.
- When the ventricle relaxes the semilunar valve shuts, stopping blood flowing back from the aorta into the ventricle.
- (a) 148 − 68 = 80 beats per minute.
- (b) The pulse rate falls quickly at first, then more slowly, returning almost to the resting rate (70, close to 68) after 6 minutes.
- (c) Repeat the whole investigation and calculate a mean; use several students.
- Keep the exercise the same (same distance, speed and time) and rest until the pulse is back to resting before each repeat.
- Muscles contract more, so the muscle cells respire faster to release more energy.
- They need more oxygen and glucose, and produce more carbon dioxide.
- The heart beats faster so blood flows faster, delivering oxygen and glucose to the muscles more quickly...
- ...and removing carbon dioxide more quickly (in vigorous exercise, also supplying oxygen to remove lactic acid).
- Fatty deposits build up in the walls of the coronary arteries, narrowing them; a clot may block an artery completely.
- The heart muscle beyond the blockage gets less (or no) oxygen and glucose, cannot respire, and may die: a heart attack.
- Risk factors that cannot be changed: any two of age, sex (being male), genetic predisposition.
- Diet: eating less saturated fat (and salt) reduces the build-up of fatty deposits in the arteries.
- Exercise: regular exercise strengthens the heart and helps reduce body mass, blood pressure and blood fat levels.
8 multiple-choice questions on this lesson
From the topic question bank. Assign them in the app for a marked score in your gradebook, or run the topic as a class game.
Which chamber of the heart receives blood from the vena cava?
- Aright atrium
- Bleft atrium
- Cright ventricle
- Dleft ventricle
Which method of monitoring the heart records the electrical activity of the heart muscle?
- Aan ECG
- Bcounting the pulse at the wrist
- Clistening with a stethoscope
- Dmeasuring the breathing rate
The graph shows a student's heart rate before, during and after exercise. By how much did the exercise increase the heart rate?
- A80 beats per minute
- B150 beats per minute
- C70 beats per minute
- D220 beats per minute
What causes coronary heart disease?
- ABlockage of the coronary arteries that supply the heart muscle
- BBlockage of the vena cava that returns blood to the heart
- CDamage to the valves so blood flows backwards in the heart
- DA hole in the septum so blood mixes in the heart
A man has a father who had a heart attack at 50. Which change would most reduce his own risk of coronary heart disease?
- AEating less saturated fat and exercising regularly
- BEating more saturated fat to give more energy
- CExercising less to rest the heart muscle
- DNothing, because his risk is set by his genes
(Extended) When the ventricles contract, which valves are closed?
- AThe atrioventricular valves
- BThe semilunar valves
- CBoth the atrioventricular and semilunar valves
- DThe valves in the vena cava
(Extended) A baby is born with a gap in the septum between the two ventricles. Suggest the effect on the baby.
- ASome deoxygenated blood mixes with oxygenated blood, so less oxygen reaches the body
- BBlood flows backwards from the arteries into the ventricles
- CThe coronary arteries become blocked with fatty deposits
- DThe left ventricle pumps blood only to the lungs
(Extended) Which statement best explains why heart rate rises during exercise?
- AMuscles respire faster, so oxygen and glucose must be delivered and carbon dioxide removed faster
- BMuscles need more blood cells, so the heart makes more of them as it beats
- CThe heart needs more energy, so it beats faster to release energy itself
- DMuscles produce oxygen during exercise, which must be carried to the lungs
Quiz key
The vena cava brings deoxygenated blood from the body to the right atrium. The left atrium receives oxygenated blood from the pulmonary vein. The ventricles do not receive blood from veins directly; they are filled from the atria and pump blood out into arteries.
An ECG (electrocardiogram) uses electrodes on the skin to record the electrical activity of the heart as a trace. Counting the pulse measures how often the heart beats, and a stethoscope picks up the sounds of the valves closing; both monitor the heart but not its electrical activity. Breathing rate is a measure of the lungs, not the heart.
The resting rate is 70 beats per minute and the highest rate, at 6 minutes, is 150, so the increase is 150 − 70 = 80 beats per minute. 150 is the maximum rate itself and 70 is the resting rate, not the increase. 220 comes from adding the two values instead of subtracting.
In coronary heart disease fatty deposits build up in the coronary arteries and can block them, so the heart muscle receives less oxygen and glucose. The vena cava is not affected in this disease. Faulty valves and a hole in the septum are different heart problems, not coronary heart disease.
His genetic predisposition raises his risk, but diet and exercise can still lower it: less saturated fat slows the build-up of fatty deposits, and regular exercise strengthens the heart and helps lower blood fats and blood pressure. More saturated fat and less exercise both increase the risk. Genes are only one risk factor, so lifestyle changes still help.
As the ventricles contract, the pressure in them rises above that in the atria, so the atrioventricular valves shut and blood cannot flow back into the atria. The semilunar valves are pushed open so blood enters the aorta and pulmonary artery. If both sets were closed, no blood could leave. The vena cava has no valve that controls ventricular contraction.
The septum keeps oxygenated blood on the left separate from deoxygenated blood on the right. With a gap, the two mix, so the blood pumped to the body carries less oxygen and the baby may tire easily. Backflow from the arteries is stopped by the semilunar valves, not the septum. Fatty deposits in coronary arteries are coronary heart disease. The left ventricle still pumps to the body through the aorta.
Contracting muscles respire faster to release energy, so they need more oxygen and glucose and produce more carbon dioxide. A faster heart rate makes blood flow faster, delivering and removing these substances more quickly. The heart does not make blood cells. Beating faster increases the heart's own energy use rather than releasing energy for the muscles. Muscles use oxygen; they do not produce it.
What to project
The student lesson embeds these tabs. Open them full screen on the projector; every slider has a drag handle on the stage.
Slides for this lesson
A projectable deck for every pack is on the way. Until then, present the student lesson full screen: its sections, figure and lab tabs follow the same order as the plan above.