The Digestive System

The digestive system is an organ system responsible for breaking down food into small, soluble molecules that can be absorbed into the blood and transported to cells throughout the body. This lesson covers the structure and function of each organ in the digestive system, as required by the AQA GCSE Combined Science Trilogy specification (8464).

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Overview of the Digestive System

The digestive system is essentially a long tube (the alimentary canal or gut) running from the mouth to the anus, with several associated organs that assist in digestion.

graph TD
    A["Mouth"] --> B["Oesophagus"]
    B --> C["Stomach"]
    C --> D["Small Intestine"]
    D --> D1["Duodenum"]
    D --> D2["Ileum"]
    D2 --> E["Large Intestine"]
    E --> F["Rectum"]
    F --> G["Anus"]
    H["Salivary Glands"] -.-> A
    I["Liver"] -.-> D1
    J["Gall Bladder"] -.-> D1
    K["Pancreas"] -.-> D1

Exam Tip: You must be able to identify each organ on a diagram of the digestive system. Practise labelling diagrams until you can do it from memory.

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Organs of the Digestive System

The Mouth