Nerves of the Neck

• The presentation is on the nerves of the neck, presented by Dr. Ramya Rathan, Asst Professor-Anatomy, on March 1, 2025.

Learning Objectives

• List the nerves of the neck and their branches.
• Describe the beginning, end, and course of the neck nerves.
• Explain the related structures to the neck nerves.

Nerves in the Neck

• Facial nerve
• Spinal accessory nerve
• Glossopharyngeal nerve
• Pharyngeal branch of the vagus nerve
• Vagus nerve
• Hypoglossal nerve
• Internal and external laryngeal nerves

Glossopharyngeal Nerve

• Cranial nerve IX is a mixed nerve.
• It exits the cranium through the jugular foramen in the posterior cranial fossa.
• It descends down between the Internal jugular vein and Internal carotid artery.
• This nerve is located between the internal and external carotid arteries.

Branches

• Carotid branch supplies the carotid sinus and carotid body
• Pharyngeal branches
• Lingual branches
• The branch of glossopharyngeal nerve to the carotid sinus (Hering's nerve) is a small nerve in the neck that innervates the carotid sinus and the carotid body.
• It runs downwards, anterior to the internal carotid artery.

Vagus Nerve

• Cranial nerve X is a mixed nerve.
• It exists from the cranium through the Jugular foramen in the posterior cranial fossa.
• The nerve descends down within the carotid sheath between the internal jugular vein laterally, and the internal and common carotid artery medially.
• It lies in relation to the carotid triangle in the neck and enters the thorax.

Branches and Distribution

• Pharyngeal branches
• Superior laryngeal nerve.
• Branches to the carotid body and sinus, along with the glossopharyngeal nerve.
• Cardiac branches
• Right recurrent laryngeal nerve

Accessory Nerve

• Cranial nerve XI is a motor nerve
• Consists of cranial and spinal roots (spinal-accessory nerve).
• It exits through the Jugular foramen.
• At the exit, the cranial root is separated from the spinal root
• The cranial root unites with the vagus nerve, and is distributed through the pharyngeal, recurrent laryngeal, and cardiac branches of the vagus nerve.
• The spinal root enters the neck across the carotid triangle and reaches the posterior triangle of the neck.
• It distributes to the sternocleidomastoid and trapezius muscles.

Hypoglossal Nerve

• This is a motor nerve
• It exists through the hypoglossal canal in the posterior cranial fossa.
• It lies deep to the Internal carotid, Internal jugular vein, 9th, 10th and 11th cranial nerves.
• The location is in the carotid and digastric triangle; related to the submandibular gland, its duct, and ganglion.

Branches and distribution

• Descending branch with C1, supplies the thyrohyoid and geniohyoid to form a loop with C2 and C3 (ansa cervicalis)
• It also supplies all muscles of the tongue except the palatoglossus.

Sympathetic Chain

• Lies posterior to the carotid sheath.
• Has three ganglia: superior cervical, middle cervical, and inferior cervical ganglia.

Clinical Anatomy

• Glossopharyngeal nerve lesion leads to cardiac arrest/syncope
• Vagus nerve-recurrent laryngeal nerve may be injured by thyroid surgery/ compression by tumor and has impact on larynx
• Accessory nerve- irritation can cause spasm of trapezius and sternocleidomastoid muscle (torticollis)
• Hypoglossal nerve – Unilateral lesion – causes the tip of the tongue to tilt to the paralyzed side when protruded.