FIGURE 11.

A diagram from Nagaishi's text book on the functional anatomy of the lung showing a secondary lymphoid organ (i.e., a lymph node) that has a capsule and afferent and efferent lymphatics, as well as tertiary lymphoid organs that are located beneath the epithelium of airways and endothelium of lymphatic vessels. The cellular content of the tertiary lymphoid organs is similar to that observed in lymph nodes, and they are capable of forming germinal centers and may be involved in local immunoregulation. [From Nagaishi (74).]