Question

Why is small intestine longer than large

Answer 1

The small intestine is important to digestion, which takes several hours. The partially digested food has to move slowly and make lots of contact with the walls of the intestine, so a long tube with small diameter slows things down and insures proper digestion. Once digestion is complete, all that is needed is storage of the indigestible waste that is left and some reabsorption of water. The shorter but wider large intestine serves the storage function in a space-efficient manner. Each intestine is the right size and shape for the function it serves.

Answer 2

Herbivores eating grass need a longer small intestine to allow the cellulose to be digested. Whereas Meat is easier to digest, hence carnivores like tiger have shorter small intestine.