Painting of Small intestine:The small intestine in an adult human measures about 7 meters in length and is approximately 2.5-3 cm in diameter. Although the small intestine is much longer than the large intestine (typically 4-5 times longer), it gets its name from its comparatively smaller diameter. Although a simple tube the length and diameter of the small intestine would have a surface area of only about 0.5m2, the surface complexity of the inner lining of the small intestine increase its surface area by a factor of 500 to approximately 250m2, or roughly the size of a tennis court. The small intestine is divided into three structural parts: 1)Duodenum 26 cm (9.8 in) in length 2)·Jejunum 2.5 m (8.2 ft) 3)Ileum 3.5 m (11.5 ft)