Abstract
The Interscalar septum (ISS) between the apical and middle turns was dissected out of the human cochlea and morphologically studied. The ISS is a thin bony plate, in which run the radiating arterioles to the middle turn and the venules from the lower spiral ligament of the apical turn. The radiating arterioles are located within the fairly large perivascular space. Melanocytes with irregular or granular shapes adhere to the wall of the radiating arterioles. These cells also adhere to the wall of the perivascular space without touching the arteriole wall. Strands, which are possibly remnants of atrophied blood vessels are observed within the space. An avascular channel is also observed. Indian ink injected into the modiolus reaches the upper spiral ligament via the perivascular space of the radiating arteriole. It is possible that cerebrospinal fluid reaches the cochlear lateral wall through the same space to participate in formation of the perilymph.
