1a: Organs of the GI System

A System of the Body

We can think of the human body as consisting of several different systems that work together to keep us alive and functioning. Merriam-Webster defines a body system as “a group of body organs or structures that together perform one or more vital functions.” Obviously, the systems are not independent of one another, they must work together to make a healthy, fully-functioning body--still, they are a logical way for both scientists and doctors to organize their study of the body, its function, and its diseases.

One of the systems of the body is the gastrointestinal system (called the GI system for short; also called the digestive system or alimentary system). The vital functions of the GI system are to nourish and replenish the body by extracting energy, nutrients and water from our food and drink, and making these available for use by other systems of the body. An additional function is the elimination of digestive waste products by means of defecation.

What does a healthy GI system do?

According to Wikipedia, the Gastrointestinal System "converts food into small, nutritional, non-toxic molecules for distribution by the [circulatory system] to all tissues of the body, and excretes the unused residue."

The main structures of the GI system are those that make up the gastrointestinal tract (also called alimentary canal), the pathway that food passes through, from the mouth to the anus. In addition, there are several accessory organs that help the system perform its functions, for instance by creating and storing digestive liquids such as bile.

On the pages that follow, we will learn the names of the principal organs in this system.

When things go wrong

As an interpreter, you may encounter patients with gastrointestinal issues in a primary care setting such as a general medicine, adult medicine or pediatric clinic; or in a specialty clinic or hospital inpatient setting. The sub-specialty of medicine that deals with diseases of the GI system is called gastroenterology, and the doctor in this sub-specialty is a gastroenterologist. This course will mention, but will not emphasize, other disciplines that also relate to the GI system.