The interscalar septum is a thin bony plate that separates each turn of the cochlea .
It radiates from the modiolus laterally to the spiral ligament . Vessels (venules, arterioles and capillaries) run within the septum through bony canals .
Partial absence of the interscalar septum is a relatively common developmental anomaly that does not interfere with normal cochlear function .
Absence of the interscalar septum is associated with cochlear incomplete partition.