Cell bodies of lower motor neurons supplying the sternocleidomastoid and trapezius through the spinal part of the accessory nerve are located in:

• A Nucleus ambiguus of the medulla
• B Spinal trigeminal nucleus
• C Anterior horn cells of the upper five cervical segments of the spinal cord ✓
• D Lateral horn cells of T1 and T2 segments

Explanation

The spinal accessory nerve takes origin from a column of anterior horn cells in the upper five cervical spinal segments. These fibres ascend alongside the spinal cord, enter the skull through the foramen magnum, briefly join the cranial root, and then leave through the jugular foramen. The nucleus ambiguus gives rise to the cranial accessory fibres distributed through the vagus, not to the SCM and trapezius supply.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.