The digestive system is one of the most
complex systems of the body. It provides the body's means of transforming food to
energy. Food first enters the digestive system through the mouth, travels through a
series of complex, specialized organs, which churn, process, and transform it into
fuel. Fuel is mainly in the form of glucose, carbohydrates, and fat. Each life
function performed by the body relies on a specific type of fuel. For example the
brain only uses glucose.
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