Class 5 EVS

From Tasting to Digesting

Taste Buds

Everyone loves tasty food. Some of you love to have sweet candies. Some of you love to have sour imli (tamarind). Some of you love to have salty chips. Some of you love to have bitter and spicy curry. Most of you may be aware that our tongue gives us the sense of taste. But do you know which part of the tongue is most sensitive to which type of taste?

Following figure shows taste map of the tongue. It shows different parts of the tongue which are most sensitive to a particular taste.

Taste Zones on Tongue

You will be surprised to know that our nose too helps to give us the sense of taste. You do not get the taste of a food, when you are suffering from cold and your nose is blocked. Sense of smell is also necessary to detect the taste of a food.

You can check this by closing your nose and then trying to taste something. Keep your eyes closed while doing this.

Your tongue, nose and eyes work together to give the sense of taste. If a food looks good, you feel the temptation to eat that food. If a food smells good, you feel the temptation to eat that food. Nobody wants to have a food which looks bad or smells bad.


Our body cannot directly utilize the food we eat. Our body changes the food to simple substances. After that, the body can use these simple substances. The process by which food is changed into simple substances is called digestion.

Digestive System

Fig: Simple Drawing of Human Digestive System

Digestion begins in the mouth. When you chew the food, digestive enzymes mix with it. Some part of the food is digested in mouth. That is why your parents and grandparents always tell you to chew the food properly.

After that, some of the food is digested in the stomach. Digestive juice in the stomach is acidic. When there is excess acid in stomach, people suffer from acidity or hyperacidity. When someone eats too much spicy and oily food, he may get acidity. In that case, the person suffers from a burning sensation in chest. He may also have pain in abdomen.

Finally, the food is digested in small intestine. Digestion is completed in small intestine. Digestive juices from liver and pancreas come to small intestine to finish the job.


Water is necessary for life. A person can survive for many days without food. But one cannot survive for more than a few days without water. That is why your parents or teachers may tell you to drink plenty of water.

Water is necessary for all organs to work properly. When our body loses too much water, this condition is called dehydration. Dehydration can happen because of too much heat during summer. It can happen because of too much running or playing. It can also happen when someone suffers from loose motion or watery stool. Passing watery stool is called diarrhea.

After a race or a game of football, your sports teacher gives you glucose to drink. Glucose gives instant energy to the body. It also prevents dehydration. When someone suffers from diarrhea he gets dehydrated. Drinking sugar and salt (in water) helps in preventing dehydration. ORS (Oral Rehydration Solution) is very helpful in this condition. ORS comes as powder. It is dissolved in water and given to a patient of dehydration. If the condition is serious, then doctors give glucose drip to the patient. In this case, glucose is directly sent to blood through injection.