The Heart and Monitoring Heart Function

What The Heart and Monitoring Heart Function covers

The Heart and Monitoring Heart Function is examined in all three written papers — the specification states that Components 01, 02 and 03 can each assess content from any of the five modules, so nothing is confined to one paper. It covers the need for a mass transport system, structure and dissection of the mammalian heart, the cardiac cycle, initiation and coordination of the heartbeat, heart rate, pulse rate and cardiac output and electrocardiograms and emergency cardiac treatment.

The 6 subtopics

Each one has its own page.

• The need for a mass transport systemRecall questions on mass transport systems, why single-celled organisms manage by diffusion, surface area to volume ratio and its calculation, how size, multicellularity and metabolic rate create a need for mass transport, and what the mammalian blood system carries.Open →
• Structure and dissection of the mammalian heartRecall questions on the four chambers and the vessels entering and leaving them, the thick left ventricle wall, the septum, the bicuspid and tricuspid valves and tendinous cords, the coronary arteries, and identifying, dissecting and drawing a mammalian heart safely.Open →
• The cardiac cycleRecall questions on the three stages in order, what opens and closes each set of valves, pressure during diastole, the heart sounds, and calculations from a cycle's timing.Open →
• Initiation and coordination of the heartbeatRecall questions on why cardiac muscle is called myogenic, how excitation spreads across the atria, the reason for the delay before the ventricles, the route down the septum, and pacemakers.Open →
• Heart rate, pulse rate and cardiac outputRecall questions on stroke volume and calculating cardiac output, the low resting heart rate of athletes, what a pulse is and how to take one, primary and secondary data, and how heart rate and stroke volume change during and after exercise, with the variables to control.Open →
• Electrocardiograms and emergency cardiac treatmentRecall questions on the P wave, QRS complex and T wave of an ECG, calculating heart rate, tachycardia and bradycardia, S-T elevation, ventricular and atrial fibrillation, first aid and aspirin for a heart attack, cardiac arrest and CPR, and how a defibrillator works.Open →

What you need to know

Answer each one before you reveal it.

Take The Heart and Monitoring Heart Function further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Heart attack vs Cardiac arrest

  Heart attack: a blocked coronary artery, so muscle starved of blood begins to die although the pump usually keeps beating. Cardiac arrest: the pump stopping effectively altogether, so the person is unresponsive and not breathing normally.

• Atrioventricular valves vs Semilunar valves

  Atrioventricular valves: the cusps forced shut at the start of ventricular systole, giving the first heart sound and preventing backflow into the chamber above. Semilunar valves: the cusps at the exits into the aorta and pulmonary artery, snapped shut at the end of ventricular systole to give the second heart sound.

• SAN vs AVN

  SAN: the pacemaker in the wall of the right atrium that generates the regular waves of excitation setting the rhythm. AVN: the relay in the septum at the base of the right atrium that delays the wave briefly before passing it on to the ventricles.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What is a mass transport system?

   Model answer

   It is a system that carries substances in bulk over long distances within an organism, usually in a fluid moved through vessels, rather than relying on diffusion.

2. 2

   Why can a single-celled organism survive without a mass transport system?

   Model answer

   It has a very large surface area to volume ratio and every part of it is close to the surface, so diffusion alone supplies its needs fast enough.

3. 3

   State the relationship used to compare the exchange capacity of organisms of different sizes.

   Model answer

   Ratio = surface area ÷ volume.

4. 4

   What happens to the surface area to volume ratio of a mammal as its body size increases?

   Model answer

   It decreases, because volume rises with the cube of the linear dimensions while surface area rises only with the square.

5. 5

   Explain why a small surface area to volume ratio makes diffusion alone inadequate in a mammal.

   Model answer

   There is too little exchange surface for the mass of respiring tissue, and the distances from the surface to the innermost cells are far too great for diffusion to supply oxygen quickly enough.

6. 6

   Why does a high basal metabolic rate increase the need for a mass transport system?

   Model answer

   Oxygen and glucose are consumed rapidly and carbon dioxide is produced rapidly, so these substances must be delivered and removed faster than diffusion could manage.

What is inside Levo

Six ways to work the same material.

The Heart and Monitoring Heart Function revision questions

What does The Heart and Monitoring Heart Function cover in OCR A-Level Biology B?

6 subtopics: the need for a mass transport system, structure and dissection of the mammalian heart, the cardiac cycle, initiation and coordination of the heartbeat, heart rate, pulse rate and cardiac output and electrocardiograms and emergency cardiac treatment. Each one has its own page with questions and model answers.

How is The Heart and Monitoring Heart Function organised?

By the OCR H422 specification, subtopic by subtopic, so it matches the order you are taught it in.