Nutrition in Animals
Animals get their food from plants, either directly by eating plants or indirectly by eating animals that eat plants. Animal nutrition includes nutrient requirement, mode of intake of food and its utilisation in the body
Digestion: The breakdown of complex components of food into simpler substances is called digestion. The components of food such as carbohydrates are complex substances. These complex substances cannot be utilised as such. So they are broken down into simpler substances.
DIGESTION IN HUMANS
We take in food through the mouth, digest, and utilise it. The unused parts of the food are defecated.
What happens to the food inside the body?
The food passes through a continuous canal (alimentary canal) which begins at the buccal cavity and ends at the anus. The canal can be divided into various compartments: (1) the buccal cavity, (2) food pipe or oesophagus, (3) stomach, (4) small intestine, (5) large intestine ending in the rectum and (6) the anus.
Human digestive system
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| Source: NCERT |
The food components gradually get digested as food travels through the various compartments. The inner walls of the stomach and the small intestine, and the various glands associated with the canal such as salivary glands, the liver, and the pancreas secrete digestive juices. The digestive juices convert complex substances of food into simpler ones. The digestive tract and the associated glands together constitute the digestive system.
Glands ➩ salivary glands, liver, pancreas
Digestive system = Alimentary canal ( digestive tract) + Glands
The mouth and buccal cavity
Food is taken into the body through the mouth. The process of taking food into the body is called ingestion.
References
- NCERT Science Class 7
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