Online College Courses for Credit

Layers of the Alimentary Canal

Layers of the Alimentary Canal

Author: Nathan Lampson

This lesson will describe the structure, including the four layers, of the digestive tract.

See More
Fast, Free College Credit

Developing Effective Teams

Let's Ride
*No strings attached. This college course is 100% free and is worth 1 semester credit.

29 Sophia partners guarantee credit transfer.

312 Institutions have accepted or given pre-approval for credit transfer.

* The American Council on Education's College Credit Recommendation Service (ACE Credit®) has evaluated and recommended college credit for 27 of Sophia’s online courses. Many different colleges and universities consider ACE CREDIT recommendations in determining the applicability to their course and degree programs.

Terms to Know
Digestive Tract

Technically is called the alimentary canal, the digestive tract consists of the organs that perform the main functions of the digestive system: ingestion, digestion, absorption, and excretion. The organs of the digestive tract are the: mouth, esophagus, stomach, small intestine, colon (large intestine), rectum and anus.


The name used to describe the hollow part of a hollow/tubular organ.


The mucous membranes of the alimentary canal, this is the layer of tissue of the alimentary canal that is in direct contact with its lumen.


The outermost layer of tissue of the alimentary canal that produces and secretes a watery secretion to reduce friction while digestive organs are moving.

Smooth Muscle

The tissue layer of the alimentary canal that controls its muscular movements, also called the muscularis.


Sphincters are muscles that control the openings between organs; sphincters control what enters and exits various organs.


The layer of tissue just below the mucosa, the submucosa contains glands that secrete onto the mucosa and well as capillaries and lymph vessels.