The primary organs responsible for nutrient absorption in the human body are the small intestine, stomach, and large intestine.
The small intestine, in particular, plays a crucial role. It is divided into three parts: the duodenum, jejunum, and ileum. After food is broken down in the stomach, it moves into the duodenum, where it mixes with digestive juices from the pancreas and bile from the liver. This mixture is then further broken down into smaller molecules.
As the digested food moves through the jejunum and ileum, tiny hair-like structures called villi and microvilli line the intestinal walls. These structures increase the surface area and facilitate the absorption of nutrients such as carbohydrates, proteins, fats, vitamins, and minerals into the bloodstream.
While the small intestine is the main site for absorption, the stomach also contributes by breaking down food and allowing some nutrients to be absorbed directly through its lining. The large intestine absorbs water and some electrolytes, but its role in nutrient absorption is limited compared to the small intestine.