Clinical Case

An elderly patient complains about a ringing sound in his ears. Evaluation of the external ear canal and tympanic membrane revealed no abnormalities, neither did careful inspection of the nose, nasopharynx, and upper respiratory tract. The patient says he must often ask people to repeat something in a conversation. Both his father and grandfather had to use hearing aids in their later years. Which epithelium lines the membranous labyrinth? How does the utricle differ from the crista? What is unique about the stria vascularis? What does membrane of Reissner consist of? Which cells do you find in the organ of Corti? What is formed by the pillar cells? What is the basilar membrane and where is it found?

Microscopy

A very low magnification of a plane section in the longitudinal axis of the cochlear which shows the two-and-a-half turns of the cochlear, therefore, five separate cross-sections of the cochlear can be seen. Fig Coch-001

A high magnification of a cross-section through the cochlear demonstrating the different structures of the tube. Fig Coch-002

A very high magnification of the organ of Corti demonstrating the different structures. Fig Coch-003

A high magnification of the spiral ganglion in the modiolus of the inner ear. Fig Coch-004

Semicircular canal

Slide 119 (H & E)

A very high magnification of the structure of a crista ampularis in one of the ampullae of the semicircular canals. Fig Crista-001

Membranous Labyrinth

Slide 120 (H & E)

A very high magnification of the structure of the macula in the utricle or saccule of the membranous labyrinth. Fig Makula-001

Tympanic Membrane

Slide 116 (H & E)

A low magnification of the tympanic membrane demonstrating the structure and attachment to the skull. Fig Trom-001

A very high magnification of the tympanic membrane demonstrating the structure and layers. Fig Trom-002