Instruction: pick the one best answer. This is also useful on the USMLE step 1. 1. What is another term for lymphatic nodules? a. Lymph follicles b. White pulp c. Peyer's patches d. Lymph node e. Diffuse lymphatic tissue Answer: a The localized concentrations of lymphocytes that are seen in the respiratory tract, genitourinary tract, and gastrointestinal tract are lymph follicles. They are also called lymphatic nodules. The lymphatic tissue in the spleen is called white pulp. The large aggregates of lymphatic tissue in the ileum are called Peyer's patches. A lymph node is an encapsulated lymphatic organ. The random distribution of lymphocytes seen in the lamina propria of the respiratory tract, genitourinary tract, and gastrointestinal tract is called diffuse lymphatic tissue. Difuse lymphatic tissue in not encapsulated. 2. Which layer of the gastrointestinal tract contains the gut associated lymphatic tissue? a. Mucosa b. Sub mucosa c. Muscularis externa d. Serosa e. Adventiti