8 Functions of Small and Large Intestine - Small Intestine vs Large Intestine

Small intestine: It is the longest part of alimentary canal which measures between 4.5 to 7 m in length. The term small intestine is used because this part of the alimentary canal has narrowest diameter. Small intestine lies coiled in the abdomen. Small intestine has 3 parts: Duodenum, jejunum and ileum.

Functions of Small Intestine:

1. Small intestine is the major seat of absorption of digested food. For this, it has villi for increasing its absorptive surface by 10 times.

2. Digestion of all digestible components of food is completed.

3. It produces a number of hormones for controlling the secretary and absorptive activity of different parts. The important hormones are secretin, cholecystokinin, villikinin, enterogasterone, motlin, enterocrinini and duocrinin. 

See also: Difference between Small and Large Intestine

Large Intestine: It is the hindermost part of alimentary canal which opens to the outside through the anus. The larger intestine is called large because it has a wider diameter(4-6 cm) as compared to small intestine (3.5-4.5 cm). The length of large intestine is about 1.5 m. It has 4 regions: caecum, colon, rectum and anal canal.

Functions of Large Intestine:

1. Absorption of water, so as to convert the liquefied indigestible matter into faecal matter.

2. Toxic metals and other toxins are secreted into the faecal matter in the region of large intestine.

3. It stores faecal matter temporarily.

4. It harbours symbiotic bacteria. The bacteria produce vitamins K, thiamine, riboflavin and B12.

5. Its lining layer has mucous glands for lubrication of the solidified faecal matter.