Which organ is primarily responsible for nutrient absorption in the digestive system?

The small intestine is primarily responsible for nutrient absorption in the digestive system. It plays a crucial role in breaking down food and absorbing the nutrients into the bloodstream. This organ is lined with villi, tiny finger-like projections that increase the surface area available for absorption, making the process more efficient. As food passes through the small intestine, the walls of this organ secrete enzymes and receive bile from the liver, which aid in the digestion of carbohydrates, proteins, and fats.

The large intestine is primarily involved in the absorption of water and electrolytes and the formation of feces, rather than nutrient absorption. The rectum serves as a storage site for fecal matter before it's expelled from the body. The stomach plays a role in the initial breakdown of food using gastric acids and enzymes but is not where nutrient absorption primarily occurs. Therefore, the small intestine's unique structure and function make it the central organ for nutrient absorption in the digestive process.