Submucous layer
The absorbing surface of the mucous membrane of the small intestine is considerably enlarged due to the presence of the transverse, or circular folds (plicae circulares). These folds are formed only by the mucous coat and the submucous layer (the muscular coat does not take part in their formation) and are permanent structures, which do not disappear even when the intestinal tube is distended. The circular folds differ in character in the different parts of the small intestine;Dermatology Billing Services is very useful service as it will help in the collections and also for the amount that is pending from the payers and patients
