Lacteals facilitate the transportation of digested fats from the villi of the small intestines, according to the University of the Western Cape's Department of Biodiversity and Conservation Biology. Each of the villi is linked to a lymphatic vessel called a lacteal. Lacteals form a component of the lymphatic system, which is designed to absorb and transport material that is too large to enter the blood system directly.
According to The Human Gastrointestinal Tract, fatty acids and monoglycerides are processed into fats as they penetrate cells of the villi. The synthesis produces tiny droplets of fats that are removed from the villi via exocytosis into the lacteals. Lacteals are a little larger than blood capillaries in diameter and are closed on one end, as described by the University of the Western Cape's Department of Biodiversity and Conservation Biology.
As the National Center for Biotechnology Information explains, lacteals account for the transportation of almost all dietary fats that are carried in in the form of chylomicrons from the gut to the blood system via the lymphatic system. That role of the lymphatic system makes it possible for postprandial fats to be present for the storage and conversion into energy in the entire body before the lipids enter the liver. However, the mechanism behind the regulation of lipid uptake into lacteals is not clearly understood.