Final answer:
The central pillar of bone within the cochlea of the inner ear is called the modiolus. It supports the structure of the cochlea and contains blood vessels and nerves that supply the sensory cells responsible for hearing. It also connects the cochlea to the brain.
Step-by-step explanation:
The central pillar of bone within the cochlea of the inner ear is called the modiolus. The modiolus is a central core that supports the structure of the cochlea and contains blood vessels and nerves that supply the sensory cells responsible for hearing. It also serves as a pathway for the transmission of signals from the cochlea to the brain.