Lymphoid follicles similar to lymph nodes or the tonsils, located especially in the lower small intestine. They contain white blood cells, defend against invading bacteria and try to prevent inadequately digested food particles from crossing the gut wall and entering the blood. They are one of the organs of the immune system which also includes the lymph nodes, spleen, thymus, tonsils and the appendix.

	Lymphatic Congestion The Condition "...The secondary lymphoid organs include lymph nodes, spleen, appendix, tonsils, adenoids and Peyer's patches (lymphoid tissue present in the small and large intestines)..."

Last updated: May 10, 2007