Fig. 2

Subgross photomicrograph of a normal canine ear. An intact tympanic membrane (arrows) separates the external acoustic meatus (e) from the tympanic cavity (t). The tympanic cavity, a sagittal section of the cochlea (c), utriculus (u), and sacculus (sa) and vestibulocochlear nerve (vcn). The facial nerve (fa), the stapedius muscle (s), the facial canal foramen (arrowhead), semicircular canals (sc), endolymphatic sac (es) and manubrium (m) of the malleus are depicted in this image. The trigeminal nerve (tn) is present rostral to the cochlea. Note that the plane of section is different between Figs. 2 and 3. This section was collected from a 5-year-old German shepherd with heartworm. Haematoxylin and eosin stain, bar: 4 mm