Figure 2.

SR‐PCI, 3D reconstruction, and section near the fundus of a right human IAC. The vestibulo‐cochlear complex has separated into the auditory (red) and vestibular (green) nerve branches. There is a small connection between the nerves. In this region, the SiN supplying the posterior ampule is seen. The vestibular nerve divides into the SVN and IVN. The arachnoid membranes forming the medial and superior wall of the cistern are seen. Some vessels run in the membrane at the roof. There are several pillars between the nerves and the wall of the IAC. Upper inset shows X‐ray section at the corresponding level. The lateral wall of the cistern has merged with the IAC bony surface (arrows). Lower inset shows histological H&E‐stained celloidin section of the FN with attached arachnoid (arrow). Histological section was kindly provided by Dr. Charles Liebermann, Massachusetts Eye and Ear Infirmary, Boston, MA, USA.