Variants and anomalies of the autonomic nervous system
Last reviewed: 19.10.2021
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
The upper cervical node of the sympathetic trunk is variable in shape and size. Rarely, it is divided into three separate nodes (intermediate nodes) connected by interstitial branches.
The upper cervical cardiac nerve can begin not from the upper cervical node, but from the sympathetic trunk. Often the upper cervical cardiac nerve is connected to the branches of the recurrent laryngeal nerve and the branches of the lower cervical node of the sympathetic trunk. The neck part of the sympathetic trunk sometimes doubles.
The middle cervical node is often connected by a connective branch with the diaphragmatic nerve of its side. The cervico-thoracic (stellate) node sometimes doubles, rarely triples, occasionally has a connecting branch with the diaphragmatic nerve. The external carotid plexus can give branches to the winged nodule.
There is an additional upper or lower ciliary node. The connecting branch to the ciliary node originates directly from the trigeminal node, or from the initial part of the frontal nerve, or (very rarely) from the tear nerve.
The number of thoracic nodes of the sympathetic trunk varies from 5 to 13. From the first thoracic node the connecting branch often leaves the lower cervical cardiac nerve.
The large thoracic inner nerve sometimes originates from the second and third thoracic sympathetic nodules. The aortic thoracic plexus is often associated with the posterior pulmonary plexus. Rarely sympathetic trunk is interrupted at the level between the last lumbar and I sacral vertebrae. The number of lumbar nodes in the sympathetic trunk is individually from 1 to 7, sacral - from 2 to 6 (more often 4 nodes).