Where does most absorption of the end products digestion into circulatory system?

Most of the absorption of the end products of digestion into the circulatory system occurs in the small intestine. The small intestine is the longest part of the digestive tract and is where most of the digestion and absorption of nutrients takes place. The small intestine is lined with tiny finger-like projections called villi, which increase the surface area for absorption. The villi are covered in microvilli, which are even smaller projections that further increase the surface area for absorption. The nutrients that are absorbed from the small intestine are transported to the liver through the portal vein.