Introduction 
A.		Digestion refers to the mechanical and chemical breakdown of foods so that nutrients can be absorbed by cells.d.	The outer layer, or serosa, is composed of the visceral peritoneum that protects underlying tissues and secretes serous fluid to keep the canal from sticking to other tissues in the abdominal cavity.(The lumen is the space inside the intestine)
b.	The next layer is the submucosa, which is made up of loose connective tissue housing blood lymph vessels and nerves; it nourishes the surrounding layers of the canal.a. 	The inner layer is the mucosa, 	which is lined with epithelium attached to connective tissue; it protects tissues of the canal and carries on secretion and absorption.The wall of the alimentary canal consists of the same four layers throughout its length, with only slight variations according to the functions of specific sections of the canal.C.	Movements of the Tube 
		1.2.3.