A-Level Biology: The Heart, Lungs and Disease Data

The heart and lungs are where A level biology most often turns into data analysis. Questions give pressure readings from the cardiac cycle, breathing rates and tidal volumes, lung-function results from patients, or figures linking a risk factor to heart disease, and ask you to calculate, interpret and evaluate. This material concentrates on those skills; the adaptations of the alveoli, tissue fluid and the structure of blood vessels are practised in the gas exchange and mass transport material of this category.

For the heart you revise its gross structure — the four chambers, the thicker wall of the left ventricle and why, the atrioventricular and semilunar valves, the coronary arteries and the major vessels — and then apply one rule to pressure data: a valve opens when the pressure behind it is higher than the pressure in front of it. Given the pressures in the atrium, ventricle and aorta at one moment, you decide which valves are open and what stage of the cycle it is. Cardiac output is calculated in both directions (stroke volume × heart rate, and stroke volume from output and rate) with careful conversion between cm³ and dm³.

For the lungs you describe the breathing mechanism in terms of muscles, volume and pressure, calculate pulmonary ventilation as tidal volume × breathing rate, and interpret lung-function measurements such as FEV₁ and FVC. Fibrosis, asthma and emphysema are compared by what they do to diffusion distance, surface area, airway width and elastic recoil, and so to the data.

The disease part explains how an atheroma forms and can lead to thrombosis, aneurysm or myocardial infarction, and how to handle risk-factor data: what a correlation does and does not show, and why confounding variables and sample size matter.

The material offers a multiple-choice quiz with worked explanations, a flashcard deck of structures, formulae and definitions, a printable written-work sheet of eight open questions (calculations, data interpretation and explanations) answered by hand and checked, and an oral exam in which an examiner asks one question at a time and gives feedback at the end.

The content is based on the gas exchange and mass transport content of the DfE A level biology subject content, as taught in current exam-board specifications (for example AQA topic 3, including the heart and lung disease data). It is practice material and does not replace your own board's specification, and it is not medical advice.

• Describe the gross structure of the human heart and relate the thickness of chamber walls to their function
• Use pressure data to decide which heart valves are open or closed
• Calculate cardiac output, stroke volume and pulmonary ventilation rate with correct units
• Explain the mechanism of inspiration and expiration
• Interpret FEV₁ and FVC data for fibrosis, asthma and emphysema
• Explain atheroma formation and its consequences, and evaluate risk-factor data

Practice material written by Zestly, based on the DfE A level biology subject content (exchange and mass transport: the heart, ventilation, lung disease and cardiovascular disease data).