7th Class Science Nutrition in Animals Digestion in Animals

Digestion in Animals

Category : 7th Class

Digestion in Animals

Digestion of food in animals include mainly four stages, that is, ingestion, digestion, absorption and excretion.

The process of taking food inside the body is called ingestion.

The process, by which the food is broken down into small pieces by the digestive juice, is called digestion.

The digested food is absorbed by the intestine, which is called absorption.

Undigested food and waste materials from the body are released in the form of stool and urine. This process is called as excretion.

Look at the following picture of digestive system of herbivorous and carnivorous Animal:

Digestive system of a cow Digestive system of a lion

Digestive system of a Herbivorous Animal

Digestion of food begins in the mouth of a herbivorous animal. Ingested food is first broken down into small pieces by teeth. Tongue mix it with saliva, secreted from salivary glands. The partly digested food from mouth is transported to stomach through esophagus.

The stomach of a cow is divided into four chambers, as shown in the given picture. The first and largest part of the stomach is rumen. There are certain bacteria, present in the rumen part, help in digesting cellulose carbohydrates. Thus food is partially digested in rumen, which is known as cud.

When the cattle are in rest, the cud (partially digested food) is slowly brought back into mouth for re-chewing. The completely chewed food then go to the small intestine, through the other chambers of stomach. The abomasum part of the stomach secretes hydrochloric acid and digestive enzymes. The omasum part of the stomach absorbs water. The small intestine receives digestive enzymes released by pancreas and liver. Here, in small intestine, complete digestion and absorption of digested food takes place. The food is then send to large intestine, where the remaining water is absorbed .The undigested food is transported further to be expelled out of body.