How does your small intestine absorb nutrients from food?

The small intestine absorbs nutrients through its inner lining, which is covered in tiny finger-like projections called villi, and even smaller projections called microvilli, collectively forming the brush border. These structures dramatically increase the surface area available for absorption. As digested food passes through, nutrients cross the intestinal wall through several mechanisms. Simple sugars and amino acids are absorbed via active transport and facilitated diffusion into the bloodstream through capillaries in the villi. Fatty acids and glycerol are reassembled into triglycerides and packaged into structures called chylomicrons, which enter the lymphatic system through lacteals. Vitamins, minerals, and water are also absorbed along the way, with different nutrients being taken up in different sections of the small intestine.