The digestive and respiratory systems

Our body is made of many tiny cells. Cells need nutrients to grow and work. Protein builds cells (meat, fish, eggs, milk, beans), carbohydrates are the “fuel” for energy (bread, cereals, potatoes, fruit), and fats are an energy store and help the body work. Vitamins and mineral salts are needed too. The digestive system starts at the mouth: teeth grind the food, the tongue mixes it, saliva moistens it and begins breaking down carbohydrates. That is why food should be chewed well. Then food goes down the oesophagus to the stomach, where it mixes with stomach juice. After that it passes to the duodenum and small intestine, where nutrients are absorbed into the blood. The remains reach the large intestine, which absorbs water, and the waste leaves the body. The food pyramid advises plenty of bread and cereals, vegetables and fruit, less meat and dairy, and very few sweets.