Where does the majority of digestion and nutrient absorption occur?

The small intestine is the primary site for digestion and nutrient absorption in the human body. It is divided into three parts: the duodenum, jejunum, and ileum. The process of digestion begins in the stomach but significantly intensifies in the small intestine where enzymes from the pancreas and bile from the liver aid in breaking down food.

As the food moves through the small intestine, nutrients such as carbohydrates, proteins, and fats are absorbed through the intestinal walls into the bloodstream. The large surface area of the small intestine, enhanced by villi and microvilli, allows for efficient absorption of these nutrients.

In contrast, the stomach primarily focuses on the mechanical breakdown of food and initial chemical digestion through gastric juices but does not absorb significant nutrients. The large intestine primarily absorbs water and electrolytes, with minimal nutrient absorption. The esophagus is mainly a conduit for food to move from the mouth to the stomach and does not play a role in digestion or absorption. This makes the small intestine the correct answer as it is where the majority of digestion and nutrient absorption take place.