Abstract
New information concerning the morphology and cell biological aspects of the tubotympanum related to its normal physiology and pathophysiology are reviewed. The tensor veli palatini muscle appears to have two separate insertions, and the possible role of autonomic innervation to the tubotympanum is discussed. Several defense mechanisms are provided in the tubotympanum, such as the mucociliary system, lymphatic system, immune system, and secretory system. The secretory products in the tubotympanum are diverse and complex and serve various important biologic functions. When dysfunction of these elements occurs, the tubotympanum may be subject to otitis media with effusion.