Food contains various components like carbohydrates, proteins, fats, vitamins, minerals, etc.

Various steps involved in digestion of these nutrients are as follows

Also Check – Human Alimentary Canal Diagram

5 Important Steps Involved in the Process of Digestion in Human Beings

• Ingestion
• Digestion
• Absorption
• Assimilation
• Egestion

Ingestion

• It is the process of intake of food by mouth. 
• Food is moistened by saliva, before swallowing, masticated by teeth into smaller particles.

Also Check – Human Digestive System

Digestion

• The process of breaking down large organic molecules (like carbohydrates) into smaller molecules (like simple sugars) is called digestion.
•  It is done with the help of enzymes.

Steps of Digestion are as follows 

Carbohydrates digestion initiates inside the mouth. Starch is converted to simple sugars by salivary amylase.

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Proteins are converted into peptones with the help of pepsin and rennin.

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Emulsification of fats with the help of bile juices.

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Breakdown of emulsified fats by lipase.

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Complete conversion of proteins to amino acids,complex carbohydrates into glucose and fats into fatty acids and glycerol.

Also Check – What is the role of Saliva in the Digestion of Food?

Absorption

• It is the process by which digested food passes from the alimentary canal into the blood.
• All the digested food is taken up by the walls of intestine, which has numerous villi and lacteals (small lymph capillaries found in the villi of the small intestine)

Also Check – How is the Small Intestine designed to absorb Digested Food ?

Assimilation

• It is the distribution of digested food products to various cells of the body. 
• The villi in the small intestine are richly supplied with blood vessels, which take up the absorbed food to each and every cell of the body.
•  It is then utilized for obtaining energy, building up new tissues and repairing the older ones.

Also Check – How are Fats Digested in our Body ? Where does this process take place?

Egestion

The elimination of undigested food formed in the colon of the large intestine through anus is called egestion. 

Peristalsis gradually pushes the undigested food from the small intestine to the large intestine.

Also Check – Peristalsis and Peristaltic Movement

The remaining material after reabsorption of water and ions is stored in the rectum for sometime and is ultimately removed from the body through anus.