Question

All of the following are correct with respect to the intestine of humans except

• A. colon is divided into - ascending, descending, transverse and sigmoid
• B. duodenum is C-shaped structure
• C. taenae & haustra is present all along the length of intestine
• D. highly developed villi are restricted to small intestine

Answer 1

The correct option is C taenae & haustra is present all along the length of intestine

The longest part of the alimentary canal is the small intestine. It is called the small intestine since it is small in diameter. The small intestine is divided into three parts. The C- shaped structure of the small intestine is called duodenum. The duodenum opens into the jejunum, which is the middle part of the small intestine. Ileum is the longest part of the small intestine. The jejunum opens into the ileum and ileum further opens into the large intestine. Both ileum and jejunum are coiled. But comparatively ileum is more coiled than jejunum.
The part of the intestine with the larger diameter is called the large intestine. Thus, the diameter of the large intestine is larger than that of the small intestine. The large intestine is 1.5 metres long and is divided into three parts- caecum, colon and rectum.
Caecum is a pouch-like structure which is about 6 cm. The vermiform appendix (commonly called the appendix) is an outgrowth of the caecum. The caecum leads into the colon which is divided into 4 regions- ascending colon, transverse colon, descending colon and sigmoid colon . Ascending colon is the shortest part of the colon. The colon has three longitudinal bands called taeniae coli and small pouches called haustra (singular haustrum). These haustra give the colon a segmented appearance. The sigmoid colon opens into rectum. The rectum comprises the last 20 cm of the digestive tract and terminates into the 2 cm long anal canal. The opening of the anal canal is called anus.