Villi and microvilli of small intestine

Category B - full version without watermark 720x576 (check terms and conditions at www.teledesign.de) The version with watermark is for free to embed. Description: The inside of the small intestine is so rough, because it is covered with many up to 1.5 millimeter long protrusions, the villi. By this means, the surface of the intestinal wall is already increased by about 25 times. But that's not all! Each villus has again countless tiny protuberances. This results in a contact area of no less than about 125 square meters within the small intestine. This corresponds to a square of more than eleven times eleven meters.