Eustachian Tube-Auditory Tube

The Eustachian tube 1 connects the nasal part of the pharynx and the middle ear. It is about 35–40 mm long. There are a bony part (pars ossea) 2 and a cartilaginous part (pars fibrocartilaginea ) 3 with different wall components. In the medium part of the cochlea, the human hyaline tub e cartilage has the form of a hook . The lamina membranacea (basal plate) 4 covers the tube opening which has an oval shape in this segment. The part of the tub e that is close d by the hook-shape d tub e cartilage ( stapes) and the basal plate takes the role of a pressure compensating tub e 5 . The epithelium of the mucous membrane is a multilayered ciliated epithelium with goblet cells. The lamina propria 6 of the tubular mucous membrane contains seromucous glands. It  also contains lymphocytes. Cross-section of the pars fibrocartilaginea tubae

of the guinea pig.

1 Eustachian tube

2 Bone

3 St apes, hyaline tube cartilage (ossicle)

4 Basal plate (closes the oval window), lamina membranacea

5 Pressure compensation tube with parietal multilayered ciliated epithelium, which contains goblet cells

6 Lamina propria with lymphocytes

Stain: azan; preparation; magnification: × 10

References

Kuehnel, W.(2003). Color Atlas of Cytology, Histology, and Microscopic Anatomy. 4^th edition . Institute of Anatomy Universitätzu Luebeck Luebeck, Germany . Thieme Stuttgart · New York .