Cervical Part of the Sympathetic Trunk

• Both sympathetic trunks (left and right) join to create ganglion impar and they both go from the base of the skull to the base of coccyx.
• The cervical part of Sympathetic trunk is located in front of the transverse processes of cervical vertebrae and neck of the 1st rib behind the carotid sheaths and in front of prevertebral fascia. Location is 1 on either side of cervical part of the vertebral column.

As the internal carotid nerve accompanying the internal carotid artery, every trunk is constant upwards into the cranial cavity. It becomes constant with the thoracic part of the sympathetic chain in the neck of the 1st rib, inferiorly.

The cervical part of sympathetic trunk does give gray rami communicantes to all the cervical spinal nerves but doesn’t get the preganglionic fibres via white rami communicantes from the cervical sections of the spinal cord. Every trunk gets preganglionic fibres from lateral horn cells of T1-T4 spinal sections.

Cervical Sympathetic Ganglia

There are just three cervical sympathetic ganglia: superior, middle and inferior. They’re created by the fusion of 8 archaic ganglia, corresponding to 8 cervical nerves. The features of these ganglia are as follows:

Plexus around Subclavian Artery

• Its spindle shaped and about 2.5 cm long.
• It is located just below the skull, in front of transverse processes of C2 and C3 vertebrae, behind the carotid sheath and in front of the prevertebral fascia.
• It’s created by the fusion of 4 archaic cervical ganglia.

Middle Cervical Ganglion

• It’s quite small and frequently absent.
• It is located in the lower part of the neck, in front of transverse process of C6 just above the inferior thyroid artery.
• It’s created by the fusion of the 5th and 6th archaic cervical ganglia.

Inferior Cervical Ganglion

• It’s created by the fusion of the 7th and 8th archaic cervical ganglia.
• It’s usually fused with the 1st thoracic ganglion to create the cervicothoracic ganglion; it’s also referred to as stellate ganglion due to its star shaped look.
• It is located between transverse process of C7 and the neck of the rib.

Branches

Every of the 3 ganglia supplies 3 common types of branches, viz.

• Gray rami communicantes to cervical nerves.
• A cardiac branch/nerve.
• A branch or branches to create a plexus around an artery.

Branches of Superior Ganglion

All these are as follows:

• Gray rami communicantes to ventral rami of upper 4 cervical nerves.
• Superior cardiac nerve.
• Carotid branches create sympathetic plexus around internal and external carotid arteries.

Along with the above mentioned branches, superior ganglion also supplies rise to a pharyngeal branch, which takes part in the formation of pharyngeal plexus of nerves.

Branches from Middle Ganglion

All these are as follows:

• Gray rami communicantes to ventral rami of C5 and C6 spinal nerves.
• Thyroid branches to create a plexus around the inferior thyroid artery.
• Middle cervical cardiac nerve.

Along with the above mentioned branches, the middle cervical ganglion also supplies rise to tracheal and esophageal branches.

Branches from Inferior Ganglion

All these are as follows:

• Gray rami communicantes to ventral rami of C7 and C8 spinal nerves.
• Inferior cervical cardiac nerve.
• Vertebral and subclavian branches, which create plexus around vertebral and subclavian arteries, respectively.
• Ansa subclavia is a nerve loop around subclavian artery attaching middle and inferior cervical ganglia.

Clinical Significance

Horner’s Syndrome

The head and neck region is supplied by the sympathetic fibres, which originate in the upper thoracic spinal sections. These preganglionic fibres go through stellate ganglion to relay in the superior cervical sympathetic ganglion. The postganglionic fibres originate from cells of the ganglion and supply the structures in the head and neck.

An injury to cervical sympathetic trunk generates a clinical illness named Horner’s syndrome.

Characteristic features

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• Partial ptosis (partial drooping of upper eyelid), because of paralysis of smooth part of levator palpebrae superioris muscle (Muller’s muscle).
• Miosis, i.e., constriction of the pupil, because of paralysis of dilator pupillae.
• Anhydrosis, i.e., loss of perspiration on that side of face, because of psuedomotor and vasoconstrictor denervation.
• Increased temperature and redness.
• Enophthalmos, i.e., deep-set eyeball, not verified by ophthalmometry.
• Loss of ciliospinalreflex, i.e., pinching the skin of the back of neck doesn’t create dilation of the pupil, which in healthy man happens.