The heart and lungs

5 lessons in Organisation.

31 exam questions · 67 marks

2.8 The lungs and gas exchange The structure of the lungs, from the trachea to the alveoli, and how alveoli are adapted for gas exchange: a large surface area, thin walls, a good blood supply and ventilation keep oxygen and carbon dioxide diffusing quickly. AQA Edexcel OCR 6 questions 2.9 The heart How the double circulatory system works, the four chambers of the heart, its valves and major blood vessels, why the left ventricle has the thickest wall, the coronary arteries and the pacemaker. AQA Edexcel OCR 7 questions 2.10 Heart rate and cardiac output Edexcel: calculating cardiac output from stroke volume and heart rate, rearranging the equation, measuring heart rate from the pulse, and why cardiac output rises during exercise. Edexcel 6 questions 2.11 Blood vessels How the structures of arteries, veins and capillaries suit their jobs: thick elastic walls for high pressure, valves and wide lumens for low pressure, and walls one cell thick for exchange, plus how to calculate the rate of blood flow. AQA Edexcel OCR 6 questions 2.12 Blood The four parts of the blood: plasma, red blood cells, white blood cells and platelets, what each does, how red blood cells are adapted to carry oxygen, and how to recognise each in a blood smear. AQA Edexcel OCR 6 questions