Biology · AQA Paper 1
The Circulatory System
How the heart, blood vessels, lungs and blood work together to carry oxygen and nutrients around the body, and what happens when the heart is diseased. It covers the double circulatory system, the pacemaker, arteries, veins and capillaries, gas exchange in the lungs, the components of blood and the treatment of coronary heart disease, including rate calculations for blood flow. Matches AQA GCSE Biology 4.2.2.2 to 4.2.2.4. Every lesson is for both Combined Science and separate Biology, at Foundation and Higher.
Lessons
Ticks are remembered on this device only.
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1
The Heart and Double Circulation
The heart is a muscular pump that sends blood to the lungs and then round the body. This lesson names the chambers and blood vessels of the heart, follows the…
9 terms -
2
Blood Vessels
Blood travels round the body in three kinds of vessel. This lesson explains how the structure of arteries, veins and capillaries fits their jobs, and how to…
8 terms -
3
The Lungs and Gas Exchange
The lungs bring oxygen into the blood and take carbon dioxide out. This lesson follows air from the trachea to the alveoli and explains how the lungs are…
8 terms -
4
Blood
Blood is a tissue made of a liquid and three kinds of cell fragment. This lesson names each part of the blood, explains what it does and shows how to recognise…
8 terms -
5
Coronary Heart Disease and Its Treatment
Coronary heart disease is a major killer, but it can be treated with drugs, mechanical devices and transplants. This lesson explains what goes wrong in the…
9 terms
Key terms in this chapter
All 42, gathered from every lesson.
- Double circulatory system
- A circulation in which blood passes through the heart twice on each trip round the body, once to the lungs and once to the body.
- Atrium
- An upper chamber of the heart that receives blood.
- Ventricle
- A lower chamber of the heart that pumps blood out.
- Vena cava
- The vein that brings deoxygenated blood from the body to the right atrium.
- Aorta
- The artery that carries oxygenated blood from the left ventricle to the body.
- Pulmonary artery
- The artery that carries deoxygenated blood from the right ventricle to the lungs.
- Pulmonary vein
- The vein that brings oxygenated blood from the lungs to the left atrium.
- Coronary artery
- An artery that supplies the heart muscle with oxygenated blood.
- Pacemaker
- A group of cells in the right atrium that controls the resting heart rate.
- Artery
- A blood vessel that carries blood away from the heart at high pressure.
- Vein
- A blood vessel that carries blood to the heart at low pressure.
- Capillary
- A tiny blood vessel with a wall one cell thick, where substances are exchanged with the cells.
- Lumen
- The space inside a blood vessel through which the blood flows.
- Valve
- A flap inside a vein that stops blood flowing backwards.
- Elastic fibres
- Stretchy fibres in the walls of arteries that let them stretch and recoil.
- Rate of blood flow
- The volume of blood that passes a point in a given time.
- Pulse
- The surge felt in an artery each time the heart pumps blood into it.
- Trachea
- The windpipe, the tube that carries air from the mouth and nose towards the lungs.
- Bronchus
- One of the two tubes that branch from the trachea, one into each lung.
- Bronchiole
- A smaller tube that branches from a bronchus and ends in alveoli.
- Alveolus
- A tiny air sac in the lungs where gas exchange takes place.
- Gas exchange
- The swapping of oxygen and carbon dioxide between the air and the blood.
- Ventilation
- Breathing, which moves fresh air into the lungs and stale air out.
- Concentration gradient
- A difference in the concentration of a substance between two places.
- Capillary network
- The net of tiny blood vessels that surrounds each alveolus.
- Plasma
- The pale yellow liquid part of the blood that transports dissolved substances.
- Red blood cell
- A cell with no nucleus that carries oxygen around the body.
- Haemoglobin
- The red pigment in red blood cells that joins with oxygen.
- White blood cell
- A blood cell with a nucleus that helps to defend the body against pathogens.
- Platelet
- A small fragment of a cell that helps blood to clot.
- Biconcave
- Shaped like a disc that is dimpled on both sides.
- Phagocyte
- A white blood cell that engulfs and digests pathogens.
- Blood clot
- A mass of platelets and fibres that seals a wound.
- Cardiovascular disease
- A disease of the heart or blood vessels.
- Non-communicable disease
- A disease that is not caused by a pathogen and cannot be passed from one person to another.
- Coronary heart disease
- A disease in which fatty deposits narrow the coronary arteries and reduce the blood flow to the heart muscle.
- Stent
- A wire mesh tube placed in an artery to hold it open.
- Statin
- A drug that lowers the level of cholesterol in the blood.
- Cholesterol
- A fatty substance in the blood that can build up in artery walls.
- Biological valve
- A replacement heart valve made from animal or human tissue.
- Mechanical valve
- A replacement heart valve made from metal or plastic.
- Transplant
- An operation that replaces a diseased organ with a healthy one from a donor.