The Breathing System
The breathing system brings air into the lungs where oxygen diffuses into the blood and carbon dioxide diffuses out.
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The breathing system brings air into the lungs where oxygen diffuses into the blood and carbon dioxide diffuses out.
- Air passes through the trachea and bronchi
- Alveoli are the site of gas exchange
- The diaphragm and ribs move air in and out
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is The Breathing System?
Within Biology, which covers cells, the human body, genetics, evolution, plants and ecosystems: the science of living things, this topic explains The Breathing System. Biology topics show how living things work, from the cell up to whole ecosystems, with models you can explore step by step.
Check that you can explain The Breathing System in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding The Breathing System helps you explain how living things stay alive and respond to their surroundings, which is central to biology exams.
The Breathing System in detail
The breathing system brings oxygen into the body and removes carbon dioxide. Air passes through the nose or mouth, the trachea (windpipe) with rings of cartilage, the bronchi, the bronchioles and finally into the alveoli. The lungs are protected by the rib cage and sit above the diaphragm.
During inhalation, the intercostal muscles and diaphragm contract, increasing the volume of the chest and lowering pressure, so air flows in. During exhalation, they relax. Mucus and cilia in the airways trap and remove dust and microbes. Breathing rate rises with exercise as the body needs more oxygen.
How the interactive helps you understand The Breathing System
Watch the cell model in the interactive. Use any sliders or buttons it offers to change the values and see how the cell model responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of The Breathing System.
Real-life uses and examples
- Use The Breathing System to interpret a diagram, graph or microscope image from a practical.
- Structure a longer answer about The Breathing System by moving from definition to example to consequence.
- Explain how The Breathing System helps a living thing stay alive, using a plant or animal example.
Common mistakes to avoid
- Using everyday words, such as “energy” or “bad”, without their scientific meaning.
- Listing the steps of a process without saying how one step causes the next.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about The Breathing System
What is The Breathing System?
The breathing system brings air into the lungs where oxygen diffuses into the blood and carbon dioxide diffuses out.
What are the most important points about The Breathing System?
The main points are: Air passes through the trachea and bronchi; Alveoli are the site of gas exchange; The diaphragm and ribs move air in and out.
Why is The Breathing System useful?
Understanding The Breathing System helps you explain how living things stay alive and respond to their surroundings, which is central to biology exams.
How can I practise The Breathing System?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to The Breathing System?
Related topics in Biology include The Circulatory System, Blood and Its Components, The Immune System.