1. DIGESTION The structure of the small intestine

2. The structure of the small intestine The ileum is well adapted for absorption It is very long – about 6m in adults The internal lining is greatly folded giving a much greater surface area. On the folds are numerous finger-like projections called villi The epithelial cell have microscopic projections called microvilli

3. The structure of the small intestine

4. Simple sugars, amino acids, salts and vitamins that have been absorbed pass out of the epithelial cells into a blood capillary inside the villus Blood travels from here to the liver via the hepatic portal vein The products of lipid digestion, the triglycerides, enter the lacteal in the villus

5. The structure of the small intestine

6. You need to learn the details of the structures of the small intestine wall as shown in your hand-out!