Absorption of lipids
Absorption of lipids is quite different from the absorption of monosaccharides and amino acids. Figure shows the process. The free fatty acids, monoglycerides and lysolecithins leave the miscelles and pass through the membrane of the microvilli to enter the epithelial cell. The miscelles may also be transported intact into the epithelipl cells.
Figure: Fatty acids and monoglycerides from the miscelles within the small intestine are absorbed by the epithelial cells and re-synthesised into triglycerides. These are then coated by protein to form chylomicrons which enter the lacteals of the small intestine
In either event, these products are used to re-synthesise triglycerides and phospholipids within the epithelial cells. Triglycerides, phospholipids and cholesterol combine with protein inside the epithelial cells to form small particles called chylomicrons that are collected by the lacteals in the intestinal villi. Absorbed lipids thus reach the venous blood through the lymphatic system.