The Lungs and Gas Exchange

The respiratory system is responsible for getting oxygen into the body and removing carbon dioxide. Gas exchange occurs in the alveoli of the lungs, where oxygen diffuses into the blood and carbon dioxide diffuses out. This lesson covers the structure and function of the lungs and gas exchange surfaces, as required by the AQA GCSE Combined Science Trilogy specification (8464).

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Structure of the Respiratory System

graph TD
    A["Nose and Mouth"] --> B["Trachea (windpipe)"]
    B --> C["Bronchi (singular: bronchus)"]
    C --> D["Bronchioles"]
    D --> E["Alveoli (air sacs)"]
    F["Ribs and intercostal muscles"] -.-> G["Protect lungs and assist breathing"]
    H["Diaphragm"] -.-> I["Sheet of muscle below the lungs that assists breathing"]