| Tympanic membrane - Anterior nasal mucosal changes 2o to chronic nasopharyngeal obstruction - large adenoids
Adenoids are one of two masses of lymphatic tissue situated on the posterior wall of the nasopharynx behind the posterior nares. During childhood these masses often swell and block the passage of air from the nasal cavity into the pharynx, preventing the child from breathing through the nose. Also called pharyngeal tonsils.
Tympanic membrane is a thin, semitransparent membrane, nearly oval in shape, that stretches across the ear canal and separates the tympanum (middle ear) from the external acoustic meatus (outer ear); called also eardrum. It is composed of fibrous tissue, covered with skin on the outside and mucous membrane on the inside. It is constructed so that it can vibrate freely with audible sound waves that travel inward from outside. The handle of the malleus of the middle ear is attached to the center of the membrane and receives the vibrations it collects, transmitting them to the other ossicles of the middle ear (the incus and stapes), which in turn transmit the vibrations to the fluid of the inner ear. |
