What are the 4 layers of the gi tract?

The walls of the alementary canal, which is from the esophagus to the large intestine, comprise of 4 layers. The are: Mucosa, Submucosa, Muscularis Externa, and the serosa. The Mucosa is the innermost, while the serosa is the outermost. The Muscularis externa is the muscle layer, and typically made up of inner circular layer and outer longitudinal layer or smooth muscle cells. The submucosa is soft connective tissue containing blodd vessels, nerve endings from the intrinsic nerve plexus, and lymph nodules as well as lymph vessels.