Question

All cranial nerves are related to parasympathetic nerve fibres except

• A. Oculomotor
• B. Facial
• C. Accessory spinal
• D. Vagus

Answer 1

The correct option is C Accessory spinal

Nerve fibres of the parasympathetic nervous system arise from the central nervous system.

Specific nerves include several cranial nerves, specifically the oculomotor nerve, facial nerve, glossopharyngeal nerve, and vagus nerve.

Because of its location, the parasympathetic system is commonly referred to as having craniosacral outflow.

The spinal accessory nerve provides motor innervation from the central nervous system to two muscles of the neck: the sternocleidomastoid muscle and the trapezius muscle.

The fibres that form the spinal accessory nerve are formed by lower motor neurons located in the upper segments of the spinal cord.

This cluster of neurons called the spinal accessory nucleus is located in the posterolateral aspect of the anterior horn of the spinal cord.

This is in contrast to most other motor neurons, whose cell bodies are found in the spinal cord's anterior horn.

Thus, the option C is correct.