Accessory nerve

Accessory Nerve

File:Accessory nerve.png

The accessory nerve, also known as the eleventh cranial nerve (CN XI).

The Accessory Nerve (also known as the eleventh cranial nerve or CN XI) is a nerve in the human anatomy that has both a cranial and a spinal part. It supplies the sternocleidomastoid and trapezius muscles, which are responsible for many movements of the head and shoulders.

Structure

The accessory nerve is unique among the cranial nerves in that it is composed of a cranial and a spinal part. The cranial part, also known as the "accessory part of the accessory nerve," arises from neurons in the medulla oblongata. The spinal part arises from neurons in the upper part of the spinal cord.

The accessory nerve and its branches.

Function

The accessory nerve provides motor innervation to the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle tilts and rotates the head, while the trapezius muscle has several actions on the scapula, including shoulder elevation, adduction, and upward rotation.

Clinical significance

Damage to the accessory nerve can result in a condition known as accessory nerve disorder, which can cause weakness in the shoulder and difficulty in lifting objects. It can also cause a drooping shoulder and difficulty turning the head.

See also

• Cranial nerves
• Nervous system
• Neuroanatomy

References

‎

---

Translate: - East Asian 中文, 日本, 한국어, South Asian हिन्दी, தமிழ், తెలుగు, Urdu, ಕನ್ನಡ, Southeast Asian Indonesian, Vietnamese, Thai, မြန်မာဘာသာ, বাংলা
European español, Deutsch, français, Greek, português do Brasil, polski, română, русский, Nederlands, norsk, svenska, suomi, Italian
Middle Eastern & African عربى, Turkish, Persian, Hebrew, Afrikaans, isiZulu, Kiswahili,
Other Bulgarian, Hungarian, Czech, Swedish, മലയാളം, मराठी, ਪੰਜਾਬੀ, ગુજરાતી, Portuguese, Ukrainian