intestinal absorption [L, intestinum, intestine, absorbare, to swallow] , the passage of the products of digestion from the lumen of the small intestine into the blood and lymphatic vessels in the wall of the gut. The surface area of the intestine is greatly increased by the presence of fingerlike projections called villi, each of which contains capillaries and a lymphatic vessel, or lacteal. Most dissolved nutrients pass quickly into the capillary bed for transport through the portal circulation to the liver. Lipids enter the lymphatic channels, which eventually rejoin the venous circulation at the thoracic duct in the neck.
