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LET'S EXPLORE The human body

How do we digest our food?

A cross-section through the mouthA cross-section through the mouthFood gives the body energy to stay alive and move about. The nutrients in food help us grow and stay healthy. Digestion means breaking food into smaller and smaller pieces and turning it into substances the body can use. Digestion begins in the mouth. Here food is mashed up by the teeth and tongue, while saliva softens it, ready for swallowing. Your tongue pushes the food into your throat. 


Muscles squeeze food along the oesophagusMuscles squeeze food along the oesophagus

From oesophagus to stomach

The muscles in the wall of the oesophagus force the food to the stomach. Here powerful digestive juices and the churning action of the stomach change it into a mush.

A sequence showing the workings of the stomachA sequence showing the workings of the stomach


The digestive systemThe digestive system

Intestines

The food is now a soup-like liquid. It is squeezed into the small intestine, where it mixes with juices from the pancreas and gall bladder. All useful substances in the food pass through the thin walls of the small intestine. They are taken by the blood to the liver. The leftovers include things like fruit skin and pips that the body cannot digest. These are pushed through the large intestine, which absorbs water from them. The waste is then stored as sludgy lumps called faeces (poo) in the rectum. This passes out of the body when we go to the toilet.

An average meal takes between three and six hours to be digested in the stomach.

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