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Variants and anomalies of the autonomic (autonomous) nervous system
Last reviewed: 04.07.2025
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The superior cervical ganglion of the sympathetic trunk is variable in shape and size. Rarely it is divided into three independent nodes (intermediate nodes) connected by internodal branches.
The superior cervical cardiac nerve may originate not from the superior cervical ganglion, but from the sympathetic trunk. Often, the superior cervical cardiac nerve is connected to the branches of the recurrent laryngeal nerve and the branches of the inferior cervical ganglion of the sympathetic trunk. The cervical part of the sympathetic trunk sometimes bifurcates.
The middle cervical ganglion is often connected by a connecting branch with the phrenic nerve of its side. The cervicothoracic (stellate) ganglion is sometimes doubled, rarely tripled, and occasionally has a connecting branch with the phrenic nerve. The external carotid plexus can give off branches to the pterygopalatine ganglion.
The presence of an additional superior or inferior ciliary ganglion is noted. The communicating branch to the ciliary ganglion originates directly from the trigeminal ganglion, or from the initial part of the frontal nerve, or (very rarely) from the lacrimal nerve.
The number of thoracic nodes of the sympathetic trunk varies from 5 to 13. From the first thoracic node, a connecting branch often departs to the lower cervical cardiac nerve.
The large thoracic splanchnic nerve sometimes originates from the second and third thoracic sympathetic nodes. The aortic thoracic plexus is often associated with the posterior pulmonary plexus. Rarely, the sympathetic trunk is interrupted at the level between the last lumbar and the first sacral vertebrae. The number of lumbar nodes in the sympathetic trunk is individual - from 1 to 7, sacral - from 2 to 6 (usually 4 nodes).