Question
Biology Question on Parts of the digestive system
In the wall of alimentary canal, what is the actual sequence from outer to inner:
A
serosa, longitudinal muscle, mucosa/ submucosa
B
mucosa, serosa, long muscle
C
serosa, long muscle, circular, submucosa, mucosa
D
serosa/ long muscle, submucosa, mucosa
Answer
serosa, long muscle, circular, submucosa, mucosa
Explanation
Solution
The wall of alimentary canal is made up of four basic layers. 1st of all there is serosa which is a thin membranous covering around oesophagus. Then there is muscle layer-outer layer of longitudinal muscles and inner layer of circular muscles. Last there is submucosa which contains a few oesophageal glands. Then comes mucosa which have several layers of flattened cells.