The tube that runs through the entire body from mouth to anus is called the.... - alimentary canal What are the four functions of the digestive system? - Ingestion Digestion Absorption Elimination This layer of the alimentary canal is the most superficial lined with epithelium, a lamina propria and muscular layer. - mucosa This layer consists of exocrine glands, blood vessels and nerve endings - submucosa This layer consists of a circular and longitudinal layer of smooth muscle. -...