Overview of Digestive Processes
The human digestive system is a complex network responsible for breaking down food, absorbing nutrients, and eliminating waste. While various organs play critical roles, the majority of digestion occurs in the small intestine.

Role of the Small Intestine
- The small intestine, comprising three sections—duodenum, jejunum, and ileum—is where most digestive processes take place.
- It is approximately 20 feet long, providing ample surface area for nutrient absorption.

Digestive Enzymes and Bile
- In the duodenum, digestive enzymes from the pancreas and bile from the liver mix with chyme (partially digested food).
- These substances break down carbohydrates, proteins, and fats into smaller molecules, making them easier to absorb.

Absorption of Nutrients
- The jejunum and ileum have tiny, finger-like projections called villi and microvilli that increase the surface area, allowing for maximum nutrient absorption.
- Essential nutrients such as vitamins, minerals, amino acids, and fatty acids are absorbed into the bloodstream here.

Limited Digestion in Other Organs
- While the stomach initiates digestion through acid and enzymes, its primary role is to break down food into a semi-liquid form called chyme.
- The large intestine mainly absorbs water and electrolytes and is involved in the formation of stool, rather than active digestion.

Conclusion
The small intestine’s structure and function make it the primary site for digestive processes. Its role in breaking down food and absorbing nutrients is crucial for maintaining overall health and well-being.