a Healthy DIGeStIVE SYStEM

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Digestion

When we have got food and water, we provide our cells with what they need to perform their functions. The nutrients from these substances are obtained thanks to the digestive system.

1. In the mouth, food is chewed and mixed with saliva to make a bolus.

2. The bolus travels down the oesophagus and reaches the stomach. It mixes with gastric juices which help break down the food and becomes chyme.

3. In the small intestine, pancreatic juice and bile from the liver continue breaking down the chyme and extracting nutrients. They are absorbed by blood capillaries and enter into the blood stream.

4. Water is absorbed in the large intestine and your gut bacteria finish the process of digestion.

5. Anything that remains or absorbed forms the faeces, which is expelled through the anus.

1 Copy and complete the sentences in your notebook.

a) The food enters the digestive system through the … .

b) In the stomach, … help break down the bolus.

c) The chyme is combined with … and bile to complete digestion.

d) Nutrients are absorbed by … in the intestine.

e) … are formed from the waste material and they get expelled.

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A healthy digestive system

There are many organs involved in digestion, each one with a specific function. The digestive tract are all the organs that food goes through from when it enters the body until it leaves. It is formed by the mouth, the pharynx, the oesophagus, the stomach and the small and large intestines. There are also some accessory organs which produce substances that are essential for the digestive process, such as the salivary glands, the liver and the pancreas.

In order to keep your digestive system healthy, you must eat good-quality nutrients, have a balanced diet, drink a lot of water and go to the toilet regularly.

2 Draw a diagram of the digestive system in your notebook. Label the parts of the digestive tract in blue and the accessory organs in red.

3 Write some questions about digestion to ask your classmates. Can they answer your questions correctly?

What happens in the mouth? How do nutrients get into the bloodstream?