Question

In the wall of alimentary canal, what is the correct sequence of layers, starting from the outside to the inside?

• A. Serosa, longitudinal muscle, mucosa, sub-mucosa
• B. Mucosa, serosa, long muscle
• C. Serosa, longitudinal muscle, circular muscles, sub-mucosa, mucosa
• D. Serosa, long muscles, sub-mucosa, mucosa

Answer 1

Answer: (C)

The alimentary canal walls have four basic tunics or layers. The outermost one is the serosa which is a thin membranous covering. Inner to serosa is the muscle layer of outer longitudinal muscles and the inner layer of circular muscles.

Then there is submucosa which is then followed by the innermost layer of mucosa. The mucosa is the epithelial membrane lining the lumen of the alimentary canal.

So, the correct answer is (C).