Page 270 - New Medley 4 Semester 1

DIGESTION OF FOOD

We all eat food. Food gives us energy and protects us against

diseases. This energy comes from the food after its digestion.
Digestion is a process by which the food is broken down into a

simpler form.
Let us understand the process of digestion.

Teeth play an important role in the digestion

of food because digestion begins in the mouth
with the chewing of food. During the chewing,
saliva is mixed with the food. Saliva changes Mouth

the starch present in food into sugar.

Next time when you eat a chapati or bread, take a Foodpipe
bite without anything else, chew it for some time
and notice its taste carefully. Does it taste sweet?
Liver
The chewed food is swallowed and pushed down Stomach

through the foodpipe into the stomach. In the Pancreas
Small
stomach, food is mixed with digestive juices. It intestine
is churned and broken down into still simpler intestine
Large
form.
The half-digested food from the stomach moves Anus

into the small intestine, which is a highly coiled Human digestive system
tube. The digestive juices from the liver and pancreas are mixed in the simpler
food here. The digestion of food is completed in the small intestine. The nutrients

from the digested food are absorbed into the blood and carried to all other parts
of the body. The undigested food goes to the large intestine, where water from

it is absorbed. Finally, the solid waste is excreted through the anus.

Knowledge Zone
1. The digestive path (alimentary canal) starts from the mouth and ends with the
large intestine. It is about 7 metres long.
Mouth 8 cm Foodpipe 25 cm Stomach 15 cm
Small intestine 5 m Large intestine 1 m 20 cm
2. The large intestine and the small intestine are called so because the diameter
of the large intestine is more than that of the small intestine.
3. No digestion takes place in the large intestine.
4. We eat about 500 kg of food per year.
5. About 1.7 litres of saliva is produced each day.

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