 Dear students, in this topic we shall discuss the features of absorptive epithelium of small intestine. Absorption is a phenomena through which the digested nutrients present in the lumen of the elementary canal are absorbed into the blood to be transported and to reach the tissues and cells of the body. Most of the absorption occurs by crossing the epithelial lining of the elium part of small intestine. The epithelial lining of the small intestine and specially of the elium part is specialized for absorptive functions. This epithelial lining has increased surface area for absorption and has a rich supply of transport system. These two features make it a specialized surface for absorption of products of digestion. First we shall discuss the adaptations of small intestine to increase the surface area for absorption. The surface area for absorption is increased by the evolution and development of certain anatomical features. For example, intestinal folds, will lie, epithelial cells on will lie and micro will lie. We shall discuss these features one by one. The intestinal folds, if we see the luminal wall of small intestine it has numerous circular folds. These folds provide increased surface for the placement of will lie which substantially increase the surface area for absorption. Will lie are finger-like projections which are present in thousands numbers on the circular folds. Her will less is a small structure whose length is about 1 mm and due to their presence, the surface of the intestine becomes velvety. If we open the intestine and see the surface, it appears velvety. That is because of the presence of will lie on it. Each will has a covering of epithelial cells. These epithelial cells form the actual absorptive surface of small intestine. The substances absorbed are actually absorbed in epithelial cells. The micro will lie many thousand closely packed cylindrical processes are present on the epical surface of each epithelial cell. Epithelial cell membrane is not smooth. In fact, one side of it which is the luminal side where the epithelial cell faces the intestinal lumen, on that surface, micro will lie are present in thousands. Each micro will is about 0.5 to 1.5 micrometer long and is about 0.1 micrometer wide. These structures increase the absorptive surface of every epithelial cell thousands of times. Dear students, these micro will lie have such a large number of them that when they take side by side, the appearance of intestinal epithelium becomes like a brush. This is why a special term is used for intestinal lining, that is brush border. That is because of the presence of micro will lie. Micro will lie increase the total capacity for nutrient absorption. Dear students, now we shall discuss the supply of transport system to the will lie and to the small intestine. A willis has a network of lymphatic vessels inside it. These blood vessels consist of arterioles, capillaries and venules. They have a whole network in the center of a willis. In addition, a willis also has a network of lymphatic vessels. The biggest of these lymphatic vessels is a central lactile which is supplied to the lower will lie. Nutrients which are taken up by the epithelial cells are transferred to blood and lymph vessels inside the will lie. Central lactile can take up comparatively larger particles as compared to the blood circulatory capillaries. Dear students, overall the intestinal epithelium which has intestinal folds, will lie and micro will lie, they collectively increase the surface area more than 500 times. Total area for absorption of the small intestine in humans is about 200 to 300 meter squares. If we look at the cylindrical area of the small intestine, that is only 0.4 meter squares. This is a substantial increase which makes about 500 times.