MCQ Detailed View

The process of digestion involves breaking down the food we eat into simpler, absorbable substances that provide energy and nutrients to the body. While digestion begins in the mouth and continues in the stomach, the complete digestion of food occurs in the small intestine. This organ is the most important part of the digestive system for nutrient breakdown and absorption.

The small intestine is a long, coiled tube divided into three parts: the duodenum, jejunum, and ileum. As the food reaches the small intestine from the stomach, it mixes with digestive juices from the pancreas and bile from the liver, which help break down fats, proteins, and carbohydrates into their simplest forms. Enzymes like amylase, lipase, and proteases act on food particles, turning them into sugars, amino acids, fatty acids, and glycerol.

The walls of the small intestine are lined with tiny finger-like projections called villi and microvilli, which increase the surface area for nutrient absorption. This ensures that essential nutrients such as glucose, amino acids, vitamins, minerals, and fatty acids pass into the bloodstream efficiently to be used by the body.

Other digestive organs play supportive roles:

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  Stomach: Breaks food into a semi-liquid form and begins protein digestion.

  
  


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  Large intestine: Absorbs water and forms solid waste but does not digest food further.

  
  


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  Liver: Produces bile that helps digest fats but is not the site where digestion is completed.

  
  

Thus, while digestion is a multi-step process involving several organs, the small intestine is where digestion is fully completed, and nutrients are absorbed to sustain life and health.