Absorption mainly occurs in the small intestine, but a portion of it is also carried out in the stomach and the large intestine. Absorption can take place in two stages in the small intestine. These are called the luminal and membranous stages.
The luminal stage of absorption takes place in the lumen and is driven by the pancreatic enzymes, while the membranous stage is driven by the intestinal mucosa enzymes. The small intestine is highly vascularized, which means that the organ is better able to transport nutrients from the epithelium to the blood. The lymphatic vessels found in the small intestine help gather nutrients, as well as collect infectious agents to help destroy them.