Gut-associated lymphoid tissue

The digestive tract's immune system is often referred to as gut-associated lymphoid tissue (GALT) and works to protect the body from invasion. GALT is an example of mucosa-associated lymphoid tissue.

Function
The digestive tract is an important component of the body's immune system. In fact, the intestine possesses the largest mass of lymphoid tissue in the human body. The GALT is made up of several types of lymphoid tissue that store immune cells, such as T and B lymphocytes, that carry out attacks and defend against pathogens.

New research indicates that GALT may continue to be a major site of HIV activity, even if drug treatment has reduced HIV count in the peripheral blood.

Components
Lymphoid tissue in the gut comprises the following:
 * Tonsils (Waldeyer's ring)
 * Adenoids (Pharyngeal tonsils)
 * Peyer's patches
 * Lymphoid aggregates in the appendix and large intestine
 * Lymphoid tissue accumulating with age in the stomach
 * Small lymphoid aggregates in the esophagus
 * Diffusely distributed lymphoid cells and plasma cells in the lamina propria of the gut