Sympathetic trunk

The sympathetic trunks consist of 20-25 vegetative ganglia of the first order and are located on the front-side surfaces of the ridge, from the base of the skull to the coccyx, where they join, forming one unpaired ganglion . At the level of C ₈ -L _2, white connecting branches (preganglionic fibers) are suitable for the nodes from the intermediate medial nuclei of the lateral horns of the spinal cord. Also, gray connecting branches (postganglionic fibers), which are axons of the neurons of these ganglia and transit (without switching) axons of the intermediolateral nuclei of the lateral horns of the spinal cord, heading to the 2nd order ganglia (prevertebral), and which are preganglionic, depart from the ganglia. Each ganglion gives the gray connective branches to certain spinal nerves (a postganglionic fiber from the sympathetic trunk approaches each spinal nerve).

Cervical

It consists of three nodes, which the preganglionic fibers from C ₈ -Th ₇ reach the ascending interstitial branches of the sympathetic trunk.

Upper Cervical Ganglion (ganglion cervicale superius)

Located in front of the transverse processes of C ₂ -C ₃ . It is the largest among the ganglia of the trunk (2.5 cm × 0.5 cm).

Gives postganglionic fibers that form the following nerves:

• The internal carotid nerve (n.caroticus internus), which accompanies the internal carotid artery and branches the deep stony nerve (n.petrosus profundus) to the pterygopalatine ganglion, the carotid-nerve drum, and the optic plexus, which leaves the sympathetic branch to the ciliary ganglion.
• External carotid nerves (nn. Carotici externi), which form the external carotid plexus.
• Common carotid plexus.
• Jugular nerve (n. Jugularis).
• Laryngeal pharyngeal nerves.
• The upper cervical cardiac nerve (n. Cardiacus cervicalis superior), of which the left goes to the superficial cardiac plexus, and the right to the deep.
• Gray connecting branches to the I-IV spinal nerves.

Middle cervical ganglion (ganglion cervicale medius)

Located at the level of the transverse process of C ₆ .

Gives:

• Middle cervical cardiac nerve (n. Cardiacus cervicalis medius), which is directed to the deep cardiac plexus.
• Gray connective branches to the V-VI spinal nerves.

Lower cervical ganglion (ganglion cervicale inferior)

It is located at the level of the head of the first rib, behind the subclavian artery.

Gives:

• The subclavian loop (two inter-nodal branches to the middle cervical node that encircle the subclavian artery from two sides).
• The lower cervical cardiac nerve (n. Cardiacus cervicalis inferior), which is directed to the deep cardiac plexus.
• The spinal nerve, which forms the spinal plexus around the spinal artery.
• Gray connecting branches to the VII-VIII spinal nerves.

Thoracic

Consists of 10-12 spindle-shaped nodes located in front of the ribs.

From it originate:

• Thoracic cardiac nerves (nn. Cardiaci thoracici) from the II-V thoracic nodes, which go to the deep heart plexus.
• Pulmonary and esophageal nerves from II-V thoracic nodes.
• Nerves to the thoracic aorta.
• Large internal nerve (n. Splanchnicus major) from preganglionic fibers transiently passing through the V-IX thoracic nodes.
• Small internal nerve (n. Splanchnicus minor) from preganglionic fibers transiently passing through the X-XI thoracic nodes.
• The lowest internal nerve (n. Splanchnicus imus) from the XII chest node; not permanent.

Lumbar

Consists of 3-5 lumbar nodes. The nodes of the right and left trunks are interconnected by transverse branches.

Each node gives back the lumbar internal nerves (nn. Splanchnici lumbales), which transit (are preganglionic).

Sacrococcygeal section

Both trunks form 4 paired and 1 unpaired node located midway from the sacral openings. The right and left nodes are interconnected by transverse branches.

From the nodes depart the sacral internal nerves (nn. Splanchnici sacrales), which transit (are preganglionic).

The sympathetic trunk node is an accumulation of pericarions of multipolar neurons with predominantly non-myelin nerve fibers (type C) surrounded by a connective tissue capsule with septa.

Preganglionic fibers approach the pericarions of the site and form synapses, in which the AX acts as a mediator (acts on n-cholinergic receptors ).

Part of the fibers passes through the nodes in transit (in particular, all internal nerves). These fibers switch to postganglionic in the 2nd order ganglia, which are part of the nerve plexuses (celiac plexus, renal plexus, etc.).

Postganglionic fibers are fibers that are actually directed into target tissues and, forming numerous synapses, have an adrenergic effect (acting on α ₁ -, ά ₂ -, β ₁ - or β ₂ -adrenoreceptors).

For the sympathetic innervation of the craniofacial region, the upper cervical knot is responsible, which gives out postganglionic fibers, which, as part of the periarterial plexuses, reach the corresponding parasympathetic nodes of the head (like radix sympathica), transit, and reach the corresponding organs:

• n caroticus internus → plexus caroticus internus → n.petrosus profundus → pterygopalatine ganglion (g. pterigopalatini) → nasal mucosa, palate, pharynx, lacrimal gland.
• n caroticus internus → plexus caroticus internus → plexus ophthalmicus → ciliary node (g. ciliare) → pupil dilator.
• nn. carotici externi → plexus caroticus externus → plexus facialis → submandibular and sublingual nodes → submandibular and sublingual glands.
• nn. carotici externi → plexus caroticus externus → plexus meningeus medius → auricle (g. oticum) → parotid gland.

Also, dendrites of sensitive pseudo-unipolar neurons that are located in the spinal ganglia and are responsible for visceral sensitivity transit through the nodes of the sympathetic trunk.

• E. Mtui, G. Grüner, P. Dockery. Fitzgerald Clinical Neuroanatomy and Neurology = Fitzgerald's Clinical Neuroanatomy and Neuroscience / Translated from English. under the editorship of Yu. A. Shcherbuk and A. Yu. Shcherbuk. - Moscow: Publisher Panfilova, 2018 .-- 400 p. - ISBN 978-5-91839-091-7 .
• S.T. Chornokulsky. Anatomy of Sudin and Nerve Tuluba (Angioneurology). - Book Plus, 2016 .-- S. 119.
• Romodanov A.P., Mosiychuk N.M., Kholopchenko E.I. Atlas of topical diagnosis of diseases of the nervous system. - 2nd ed .. - Kiev: Vishcha school, 1987. - 231 p.

• SYMPATHIC DEPARTMENT OF THE VEGETATIVE NERVOUS SYSTEM (neopr.) .