Image Based Question – 74215

The peripheral processes of spinal ganglion end at:

A. A

B. B

C. C

D. D

Correct Answer » C Explanation

Ans: C. C

(Ref. Ganong 25/e p201, 24/e p201-202)

• The peripheral processes of spiral ganglia ends at inner hair cells (marked as C in the given image).

• Cell bodies of sensory neurons around bases of hair cells are located in spiral ganglion within modiolus.
• Modiolus – Bony core around which cochlea is wound.
• 90% to 95% of sensory neurons innervate inner hair cells.
• Only 5-10% innervates more numerous outer hair cells.