The picture contains four parts:

1. A cross section of small intestine indicating the circular fold in the inner walls of the small intestine.
2. An enlarged picture of the folds in the small intestine where the presence of villi is indicated.
3. An enlarged picture of an individual villus. The parts labeled in the picture are:
   1. Capillaries
   2. Lymph vessel
   3. Vein
   4. Artery
   5. Epithelial cells
4. An enlarged picture of the epithelial cells indicates the presence of microvilli.