Spiral modiolar artery

The spiral modiolar artery is the principal arterial blood supply of the cochlea. It is a branch of the common cochlear artery (itself a branch of the labyrinthine artery, which typically arises from the anterior inferior cerebellar artery or, less commonly, directly from the basilar artery). The spiral modiolar artery courses through the modiolus the central bony axis of the cochlea and spirals along its length from base to apex.

Anatomical course and distribution:

The spiral modiolar artery travels within the modiolus and gives off radiating arterioles that supply the following cochlear structures:

• Stria vascularis the highly vascularized epithelium on the lateral wall of the scala media responsible for generating the endocochlear potential and maintaining endolymph ionic composition.

• Spiral ligament the lateral wall connective tissue structure that supports the stria vascularis.

• Spiral ganglion the collection of cell bodies of the primary auditory neurons located within the modiolus.

• Organ of Corti the sensory neuroepithelium resting on the basilar membrane, containing inner and outer hair cells.

• Basilar membrane and surrounding structures of the cochlear duct.