Medicine and DrugsScience

By: Ali Rashid

Diet, Drugs and MedicineIntroduction

• A balanced diet contains the different nutrients in the correct amounts to keep us healthy. Certain foods are not necessarily 'bad' for us, but eating too much of them could be. We will look at what food types are needed, how they are digested.

• Drugs are substances that affect our bodies. They can be medicines or recreational drugs, legal or illegal. We will look at these in detail.

After we swallow, our food passes through these organs in turn:

Oesophagus or gullet

Stomach

Small intestine

Large intestine.

STAGES OF DIGESTION

Food is digested in the mouth, stomach and small intestine.

Digested food is absorbed into the bloodstream in the small intestine.

Excess water is absorbed back into the body in the large intestine.

Any undigested food passes out of the anus as faeces (pronounced "fee-seez") when we go to the toilet.

The Liver

• The liver and the pancreas play important part in digestion. The liver produces bile, which helps the digestion of fat. The pancreas produces chemicals called digestive enzymes.

• When you eat a piece of bread, you don't wake up next day to discover it growing out of your arm! The food we eat has to be broken down into other substances that our bodies can use. This is called digestion. Without digestion, we could not absorb food into our bodies and use it.

• Digestion happens in the digestive system, which begins at the mouth and ends at the anus.

Nutrients

There are seven different nutrients: carbohydrates proteins fats minerals vitamins fibre water

• Some foods are particularly rich in certain nutrients. The table shows why we need each nutrient, and some good sources of each.

A Normal Lung

Lung of a Smoker