Review Article

Transitional Nerve: A New and Original Classification of a Peripheral Nerve Supported by the Nature of the Accessory Nerve (CN XI)

Figure 1

Cranial root of accessory exits from the caudal region of the nucleus ambiguus. The spinal root of the accessory originates within cervical spinal cord and ascends through the foramen magnum. Cranial nerves IX (not pictured), X, and both roots of the accessory exit the jugular foramen. Cranial accessory joins vagus at or beyond the jugular foramen prior to innervating musculature of the palate, pharynx, and larynx. The cranial root of the accessory nerve can be seen passing in close proximity to the spinal accessory and vagus nerves. Purely empirical observations could easily lead to misinterpretation of the cranial root of the accessory nerve. View of cadaver dissection demonstrating the extent of the spinal accessory nerve located within the cervical region of the spinal cord. Also highlighted is the laryngopalatopharngeal (currently cranial accessory) nerve.
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