Which are the parts of large intestine; explain their structure briefly?

Which are the parts of large intestine; explain their structure briefly?

The large intestine is shorter than the small intestine and it is called large because it has a wide lumen. It is arranged around the small intestine in the form of a question mark. The large intestine is about 5 feet long and has the following parts Caecum, Colon, Rectum and Anus.

The caecum is a blind dilated sac into which is connected the ileum. The mucous membrane at the point of connection of the ileum and Caecum is so arranged that it allows the contents of the ileum to pass into the caecum but prevents their return into the ileum. The caecum has a short slender worm like projection called the vermiform appendix.

The appendix is usually about 9 cms long. It is lined with mucous membrane and contains lymphoid tissue in its walls. In human beings the appendix has no specific function to perform and is regarded as a vestigial organ having been con­tinued as an organ which was present in the ancestors of human beings.