Drawing of the vagus nerve and its innervation pathways. Secrets of the vagus nerve

X. N. VAGUS

N. vagus, vagus nerve(Fig. 334, 335), which developed from the 4th and subsequent visceral arches, is so called because of the vastness of its distribution.

It is the longest of the head nerves. With its branches, the vagus nerve supplies the respiratory organs, a significant part of the digestive tract (up to the colon sigmoideum), and also gives branches to the heart, which receives fibers from it that slow the heartbeat. N. vagus contains three kinds of fibers:

1. Afferent (sensory) fibers, coming from the receptors of the named viscera and vessels, as well as from some part of the dura mater and the external auditory meatus with the auricle to the sensitive nucleus, nucleus tractus solitarii (for nuclei n. vagus, see p. 501).

2. Efferent (motor) fibers for the striated muscles of the pharynx, soft palate and larynx, and afferent (proprioceptive) fibers emanating from the receptors of these muscles. These muscles receive fibers from the motor nucleus (nucleus ambiguus).

3. Efferent (parasympathetic) fibers, coming from the vegetative nucleus Cnucleus dorsalis n. vagi). They go to the striated muscles of the heart (slow down the heartbeat) and to the smooth muscles of the vessels (dilute the blood vessels). In addition, the composition of the cardiac branches of the vagus nerve includes the so-called n. depressor, which serves as a sensitive nerve for the heart itself and the initial part of the aorta and is in charge of the reflex regulation of blood pressure. Parasympathetic fibers also innervate the trachea and lungs (narrow the bronchi), the esophagus, stomach and intestines to the colon sigmoideum (increase peristalsis), the glands and glands of the abdominal cavity embedded in the named organs - the liver, pancreas (secretory fibers), kidneys.

Parasympathetic part of the vagus nerve is very large, as a result of which it is predominantly an autonomic nerve, which is very important for the vital functions of the body. According to B. A. Dolgo-Saburov, the vagus nerve is a complex system consisting not only of nerve conductors of heterogeneous origin, but also containing intrastem nerve nodules.

Fibers of all kinds, connected with the three main nuclei of the vagus nerve, exit the medulla oblongata in its sulcus lateralis posterior, below the glossopharyngeal nerve, with 10-15 roots, which form a thick nerve trunk that leaves the cranial cavity together with the glossopharyngeal and accessory nerves through the foramen jugulare. In the jugular foramen, the sensitive part of the nerve forms a small knot, ganglion superius, and at the exit from the hole, another spindle-shaped ganglion thickening, ganglion inferius. Both nodes contain false unipolar cells, the peripheral processes of which are part of the sensory branches going to the named nodes from the receptors of the viscera and blood vessels (ganglion inferius) and the external auditory meatus (ganglion superius), and the central ones are grouped into a single bundle, which ends in sensitive nucleus, nucleus tractus solitarii.

Upon exiting the cranial cavity, the trunk of the vagus nerve descends to the neck behind the vessels in the groove, first between v. jugularis interna and a. carotis interna, and below - between the same vein and a. carotis communis, and it lies in the same vagina with the named vessels. Further, the vagus nerve penetrates through the upper opening of the chest into the chest cavity, where its right trunk is located in front of a. subclavia, and the left one on the anterior side of the aortic arch. Going down, both vagus nerves bypass the root of the lung behind on both sides and accompany the esophagus, forming plexuses on its walls, with the left nerve running along the front side, and the right along the back. Together with the esophagus, both vagus nerves penetrate through the hiatus esophageus of the diaphragm into the abdominal cavity, where they form plexuses on the walls of the stomach. The trunks of the vagus nerves in the uterine period are located symmetrically on the sides of the esophagus. After turning the stomach from left to right, the left vagus moves forward, and the right back, as a result of which the left vagus branches on the anterior surface, and the right vagus on the back. From n. vagus leaves the following branches:

A. At the head(between the origin of the nerve and the ganglion inferius):

1. Ramus meningeus - to the hard shell of the posterior cranial fossa.

2. Ramus auricularis - to the back wall of the external auditory canal and part of the skin of the auricle. This is the only cutaneous branch of the head nerves that is not related to n. trigeminus.

B. In the neck:

1. Rami pharyngei together with branches of n. glossopharyngeus and tr. sympathies form a plexus, plexus pharyngeus. From the pharyngeal branches of the vagus nerve, the constrictors of the pharynx, the muscles of the palatine arches and the soft palate are supplied (with the exception of m. tensor veli palatini). The pharyngeal plexus also gives sensitive fibers to the pharyngeal mucosa.

2. N. laryngeus superior supplies sensory fibers to the mucous membrane of the larynx above the glottis, part of the root of the tongue and epiglottis, and motor fibers - part of the muscles of the larynx (see p. 306) and the lower constrictor of the pharynx.

3. Rami cardiaci superiores often come out of n. laryngeus superior, enter the cardiac plexus. n passes through the branches. depressor.

B. In the chest:

1. N. laryngeus recurrens, recurrent laryngeal nerve, departs in the place where n. vagus lies in front of the aortic arch (left) or subclavian artery (right). On the right side, this nerve bends around from below and behind a. subclavia, and on the left also below and behind the aortic arch and then rises upward in the groove between the esophagus and trachea, giving them numerous branches, rami esophagei et rami tracheales. The end of the nerve, called n. laryngeus inferior, innervates part of the muscles of the larynx (see p. 306), its mucous membrane below the vocal cords, the mucous membrane of the root of the tongue near the epiglottis, as well as the trachea, pharynx and esophagus, thyroid and thymus glands, lymph nodes of the neck, heart and mediastinum .

2. Ramus cardiacus inferior originates from n. laryngeus recurrens and thoracic part n. vagus and goes to the cardiac plexus.

3. Rami bronchiales et tracheales, together with the branches of the sympathetic trunk, form a plexus, plexus pulmonalis, on the walls of the bronchi. Due to the branches of this plexus, the smooth muscles and glands of the trachea and bronchi are innervated, and in addition, it also contains sensory fibers for the trachea, bronchi and lungs.

4. Rami esophagei go to the wall of the esophagus.

G. In the abdominal part:

The plexuses of the vagus nerves, which run along the esophagus, continue to the stomach, forming pronounced trunks, triinci vagales (anterior and posterior). Each truncus vagalis is a complex of nerve conductors not only of the parasympathetic, but also of the sympathetic and afferent animal nervous systems and contains fibers from both vagus nerves.

The continuation of the left vagus nerve, descending from the anterior side of the esophagus to the anterior wall of the stomach, forms a plexus, plexus gastricus anterior, located mainly along the lesser curvature from which the rami gastrici anteriores, mixed with sympathetic branches, depart to the wall of the stomach (to the muscles, glands and mucous membrane) . Some branches go through the lesser omentum to the liver. Right n. vagus on the back wall of the stomach in the region of the lesser curvature also forms a plexus, plexus gastricus posterior, giving rami gastrici posteriores; in addition, most of its fibers in the form of rami celiaci go along the path a. gastrica sinistra to ganglion celiacum, and from here along the branches of vessels, along with sympathetic plexuses, to the liver, spleen, pancreas, kidneys, small and large intestines to colon sigmoideum. In cases of unilateral or partial damage to the X nerve, the disturbances mainly concern its animal functions. Disorders of visceral innervation can be relatively unsharply expressed. This is explained, firstly, by the fact that there are overlap zones in the innervation of the viscera, and secondly, by the fact that in the trunk of the vagus nerve on the periphery there are nerve cells - autonomic neurons that play a role in the automatic regulation of the functions of the viscera.

It often happens that a person leading a healthy lifestyle suddenly discovers unpleasant symptoms: a stomachache, a heartache... And this despite the fact that he does not drink, does not smoke, plays sports. The cause of anxiety may be the vagus nerve. Where it is located, what it is, how it functions and what problems it can create with well-being - let's try to figure it out!

What is the vagus nerve?

Medicine has 12 pairs of nerves emanating from the base of the skull. Each of them has its own functions and transmits signals to certain organs. The tenth pair has been called the vagus nerve, because it carries signals from the brain to almost all vital organs. The vagus nerve starts at the base of the skull and runs through the neck, chest, and abdomen.

First of all, the vagus nerve regulates the functions of:

  • swallowing;
  • vomiting;
  • cough
  • work of the stomach;
  • breathing;
  • heartbeat.

If the work of the vagus nerve is impaired, even cardiac arrest and death are possible.

Causes of diseases

In diseases of the vagus nerve, symptoms and treatment are interrelated. And the main reasons for the development of pathology can be:

  • injuries that put pressure on the nerve;
  • surgical operations during which the nerve was damaged or pinched;
  • diabetes mellitus (elevated sugar levels negatively affect the functioning of the vagus nerve);
  • viral respiratory diseases;
  • chronic diseases (HIV infection, Parkinson's disease);
  • alcoholism.

Symptoms

Depending on which part of the vagus nerve is affected, the doctor determines the symptoms and treatment for each specific case:

  • head section (severe headaches and discomfort in the ear area);
  • cervical region (swallowing function is disturbed due to paralysis of the pharyngeal muscles, voice change, suffocation);
  • thoracic region (violation of the functions of the cardiovascular and respiratory systems, which is expressed in difficulty breathing, a feeling of lack of air, pain in the chest; weakening of the cough reflex and, as a result, pneumonia);
  • abdominal region (disorder of the stomach and intestines, pain in the peritoneum, gag reflex).

If the vagus nerve is damaged, the cardiovascular system is especially affected. This is expressed in the following states:

  • the pulse decreases;
  • pressure drops;
  • shortness of breath appears;
  • pain in the region of the heart is felt;
  • feeling short of breath;
  • it seems as if there is a lump in the throat.

With damage to the nucleus of the vagus nerve, the tone of the autonomic system increases or decreases. Vegetative disorders make themselves felt by the lethargy of the body, apathy in human behavior with increased tone and irritability, irascibility - with a reduced one.

Learn also about the causes of hiccups in newborns and what causes hiccups all day long.

Vagus nerve diseases

When the vagus nerve is pinched, the following groups of diseases develop:

  • angioneurosis (diseases of the autonomic system, in which the work of blood vessels is disrupted);
  • neurasthenia (a disorder of the autonomic system, in which excitability increases and exhaustion occurs).

Among these groups, the most common are:

  • migraines - headache attacks that are episodic in nature;
  • Meniere's disease - parts of the periphery of the nervous system and the brain are affected, resulting in dizziness, hearing loss;
  • Raynaud's disease - the nervous system is affected, as a result of which the limbs and parts of the face turn pale and become cold, emotional irritability appears.

Treatment

The vagus nerve is almost untreatable. In this regard, you should always be careful and consult a doctor at the first symptoms of a nervous breakdown.

Traditional medicine offers the following remedies as treatment:

  • hormonal drugs (prednisolone);
  • multivitamin complexes with B vitamins;
  • anticholinesterase drugs (drugs that inhibit the activity of an enzyme that transmits an excitation signal to the nervous system);
  • antihistamines.

In especially severe cases, the following may be used:

  • electrical stimulation;
  • surgical methods;
  • plasmapheresis (blood purification at the cellular level).

Traditional treatment should take place exclusively under the supervision of a physician. With incorrect or untimely therapy, death may occur due to the cessation of the work of some organs of the body.

ethnoscience

With lesions of the vagus nerve, traditional medicine is ineffective. It allows only to alleviate some symptoms, but in no case cures the disease. As a preventive measure and to enhance the effect of traditional medicine methods, some herbal infusions can be offered.

  • 1 st. l. dried thyme herb pour 50 ml of boiling water and leave for 15 minutes. Drink throughout the day, breaking the serving into 4 doses.
  • Mix mint with lemon balm, pour a glass of boiling water and leave for 20 minutes. Drink during the day for 2 doses.
  • 1 st. l. clover pour 200 ml of boiling water and leave for 20 minutes. Strain and drink in 2 divided doses.
    From medicinal herbs and fruits, you can make tinctures for the treatment of the vagus nerve:
  • 50 g of thyme pour 1.5 liters of white wine. Insist for a week in a dark place. Take 10 drops, adding them to milk 4 times a day.
  • 50 g belladonna root pour 0.5 liters of vodka. Leave for 7 days and take 15 drops 3 times a day.

It should be remembered that it is almost impossible to cure the vagus nerve. You need to pay attention to the health of the nervous system. If there is a suspicion of vagus nerve disease, only the doctor will determine the symptoms and treatment. Self-medication and untimely seeking medical help can lead to death.

Table of contents for the topic "Cranial Nerves.":
  1. Facial nerve (VII pair, 7th pair of cranial nerves), n. facialis (n. intermediofacialis).
  2. Branches of the facial nerve (n. facialis) in the facial canal. Greater stony nerve, n. petrosus major. Drum string, chorda tympani.
  3. The remaining branches of the facial nerve after exiting the stylomastoid foramen (foramen stylomastoideum). Intermediate nerve, n. intermediate.
  4. Vestibulocochlear nerve (VIII pair, 8 pair of cranial nerves), n. vestibulocochlearis. Parts of the prevernocochlear nerve.
  5. Glossopharyngeal nerve (IX pair, 9 pair of cranial nerves), n. glossopharyngeus. Nuclei of the glossopharyngeal nerve.
  6. Branches of the vagus nerve in the head and neck n. vagus.
  7. Branches of the vagus nerve in the thoracic and abdominal parts n. vagus. Recurrent laryngeal nerve, n. laryngeus recurrents.
  8. Accessory nerve (XI pair, 11 pair of cranial nerves), n. accessorius.
  9. Oculomotor nerve (III pair, 3rd pair, third pair of cranial nerves), n. oculomotorius.
  10. Block nerve (IV pair, 4 pair, fourth pair of cranial nerves), n. trochlearis.
  11. Abducens nerve (VI pair, 6 pair, sixth pair of cranial nerves), n. abducens.
  12. Olfactory nerves (I pair, 1 pair, first pair of cranial nerves), nn. olfactorii.
  13. Optic nerve (II pair, 2 pair, second pair of cranial nerves), n. opticus.

N. vagus, vagus nerve, which developed from the 4th and subsequent gill arches, is so called due to the vastness of its distribution. It is the longest of the cranial nerves. With its branches, the vagus nerve supplies the respiratory organs, a significant part of the digestive tract (before colon sigmoideum), and also gives branches to the heart, which receives fibers from it that slow the heartbeat. N.vagus contains three kinds of fibers:

1. Afferent (sensory) fibers, coming from the receptors of the named viscera and vessels, as well as from some part of the hard shell of the brain and the external auditory meatus with the auricle to sensitive nucleus (nucleus solitarius).

2. Efferent (motor) fibers for voluntary muscles of the pharynx, soft palate and larynx, and efferent (proprioceptive) fibers emanating from the receptors of these muscles. These muscles receive fibers from motor nucleus (nucleus ambiguus).

3. Efferent (parasympathetic) fibers coming from vegetative nucleus (nucleus dorsalis n. vagi). They go to the myocardium of the heart (slow down the heartbeat) and the muscular membrane of the vessels (dilute the vessels). In addition, the composition of the cardiac branches of the vagus nerve includes the so-called n. depressor, which serves as a sensitive nerve for the heart itself and the initial part of the aorta and is in charge of the reflex regulation of blood pressure. Parasympathetic fibers also innervate the trachea and lungs (narrow the bronchi), esophagus, stomach and intestines. to colon sigmoideum(increase peristalsis), incorporated in the named organs of the gland and gland of the abdominal cavity - the liver, pancreas (secretory fibers), kidneys.

Parasympathetic part of the vagus nerve is very large, as a result of which it is predominantly an autonomic nerve, important for the vital functions of the body. The vagus nerve is a complex system consisting not only of nerve conductors of heterogeneous origin, but also containing intrastem nerve nodules.


Fibers of all kinds associated with three main nuclei of the vagus nerve, exit the medulla oblongata in its sulcus lateralis posterior, below the lingual tract nerve, with 10-15 roots that form a thick nerve trunk that leaves the cranial cavity together with the lingual tract and accessory nerves through the foramen jugulare. In the jugular foramen, the sensitive part of the nerve forms a small knot - ganglion superius, and at the exit from the hole - another ganglionic thickening of a fusiform shape - ganglion inferius. Both nodes contain pseudo-unipolar cells, the peripheral processes of which are part of the sensitive branches that go to the named nodes or receptors of the viscera and vessels ( ganglion inferius) and external auditory meatus ( ganglion superius), and the central ones are grouped into a single bundle, which ends in sensitive nucleus, nucleus solitarius.

Upon exiting the cranial cavity trunk of the vagus nerve goes down to the neck behind the vessels in the groove, first between v. jugularis interna and a. carotis interna, and below - between the same vein and a. carotis communis, and it lies in the same vagina with the named vessels. Further, the vagus nerve penetrates through the upper aperture of the chest into the chest cavity, where its right trunk is located in front of a. subclavia, and the left one is on the anterior side of the aortic arch. Going down, both vagus nerves bypass the root of the lung behind on both sides and accompany the esophagus, forming plexuses on its walls, with the left nerve running along the front side, and the right one along the back. Together with the esophagus, both vagus nerves penetrate through the hiatus esophageus of the diaphragm into the abdominal cavity, where they form plexuses on the walls of the stomach. Trunks of the vagus nerves in the uterine period, they are located symmetrically on the sides of the esophagus. After turning the stomach from left to right, the left vagus moves forward, and the right back, as a result of which it branches on the anterior surface left vagus, and on the back - right.

The vagus nerve (n.vagus) is the tenth pair of cranial nerves and is classified as mixed. It is divided into 4 sections according to its topography. The vagus nerve is very long and runs from the skull to the middle of the gastrointestinal tract, which is why it has such an interesting name.

Topography

The vagus nerve has a rather complex topographic anatomy. This is due to its length and the fact that the location of the right and left nerves are somewhat different from each other.

Both of these nerves begin in the same way. They are formed from a dozen fibers and come out on both sides to the base of the skull from the medulla oblongata. Then they go down through the hole in the skull. The first large node, the ganglion superius, is also located here. The second is below and is called the ganglion inferius.

After both nerve trunks have reached the upper aperture of the chest, they begin to "behave" differently. The left vagus nerve is located in front of the aortic arch, and the right one is located near the subclavian artery.

Then they go around both bronchi from behind and approach the esophagus.

It passes down through the diaphragm to the upper floor of the abdominal cavity. In the epigastric region, they are divided into many smaller branches that transmit impulses to the diaphragm, solar plexus and organs of the upper floor of the abdominal cavity.

The vagus nerve consists of the following fibers:

  • sensitive fibres. Carry impulses from the organ to the brain. Fibers from the vessels of the respiratory organs, the esophagus and stomach, the heart muscle, and the external auditory canal are suitable for the sensitive nucleus of n.vagus;
  • motor fibres. They transmit impulses in the opposite direction. From the motor nucleus, the fibers reach the muscles of the pharynx, soft palate, and larynx;
  • Parasympathetic nerve fibers. They affect the autonomic function of the heart, control the muscular membrane of the vessels. They can also narrow the lumen of the bronchi, increase intestinal motility and affect all organs that are innervated by the vagus nerve.

Functions

The vagus nerve is divided into four sections according to its location. They are different in length and in each of them smaller branches depart from the large nerve trunk, which innervate nearby organs and tissues.

The shortest head section. From this area depart fibers that innervate part of the hard shell of the brain (one of the causes of migraine), the inner ear, as well as two connecting branches that lead to the eleventh and twelfth pairs of cranial nerves.


The branches of the cervical region are responsible for the work of the muscles of the pharynx and larynx. If the vagus nerve is damaged in this section, the patient loses his voice, dysphagia appears. Also from this area depart small nerves, which are part of the cardiac and esophageal plexus.

The thoracic region ends at the level of the diaphragm. Two separate plexuses depart from it, which are responsible for the work of the esophagus and lungs. As well as two types of branches - cardiac and bronchial.

The vagus nerve ends in the abdominal region. Here it is divided into the anterior and posterior trunk, which innervate the stomach, pancreas, liver, and solar plexus.

The activity of n.vagus is increased mainly at night. This is due to the fact that he is responsible for the work of the parasympathetic division of the autonomic nervous system.

The vagus nerve slows down the heartbeat, reduces the contraction of the nasty muscles of the bronchi. At the same time, the secretion of the stomach and pancreas increases. The greatest activity of this part of the nervous system is manifested at night.

Also, the vagus nerve is responsible for the occurrence of coughing and vomiting, which are protective reflexes. We also owe the appearance of hiccups to pathological impulses that pass along the branches of the vagus nerve to the diaphragm.

Treatment of diseases is aimed at eliminating the symptoms that appear when there is a violation of the transmission of impulses along individual branches of the n.vagus.

Diseases

The vagus nerve, like any part of the nervous system, is subject to various damages. The clinical picture of the disease largely depends on the location of the lesion.

If the lesion is located inside the cranium, then most often it is compression by tumor neoplasms, the consequences of a traumatic brain injury, multiple sclerosis, ALS, or infections that are tropic to the nervous tissue.

The most common diseases that affect the peripheral part of the vagus nerve include neurasthenia, Raynaud's or Meniere's disease, nerve paralysis or paresis.

Vascular diseases are associated with the pathological work of the vagus nerve.

Symptoms of a malfunction of the vagus nerve depend on the depth, extent and location of the lesion. First of all, the work of the vocal cords is disrupted. This is due to damage in the cervical region. The voice becomes quiet, hoarse, may disappear completely. If both nerves are affected, suffocation is possible.

Swallowing problems are also a common symptom. Water or liquid food can enter the nasopharynx.

The work of the heart is disrupted. The heartbeat slows down or accelerates, its rhythm becomes uneven (arrhythmia). These symptoms prevail at night.

In case of serious damage to the n.vagus, its paralysis may occur, which leads to death.

Research methods

With symptoms that indicate damage to the 10th pair of cranial nerves, you should contact a neurologist.

The doctor first of all determines the sonority of the voice. This is a simple research method that does not require cost and effort. It is necessary to pay attention to the sound of the voice, its timbre and clarity of speech. A certain nasality may occur due to paresis of the soft palate. The timbre of the voice becomes lower due to the fact that the vocal cords cannot close tightly enough. For the same reason, the patient is not able to cough on purpose.

When examining the oral cavity, the doctor draws attention to the fact that the soft palate is relaxed and sags slightly downward. If you ask the patient to pronounce vowel sounds,
then the tongue will deviate to the side of the lesion.

As with any pathology of the nervous system, there will be a weakening of some reflexes. With this lesion, the pharyngeal and palatine reflexes will not be fully determined.

For differential diagnosis, instrumental research methods are used: computed and magnetic resonance imaging, radiography of the skull and chest organs.

Therapy Methods

Treatment of pathology of the vagus nerve should take place exclusively in a neurological hospital. This is due to the fact that it innervates vital organs (heart, lungs).

The most important stage of treatment is the elimination of the cause that caused the disease. Therefore, it is necessary to pay attention to differential diagnosis. If the disease has an infectious etiology, then the main drug of therapy is antiviral or bactericidal drugs.

The main medicines that are used to treat many diseases are steroid drugs. These include prednisolone, dexamethasone. The course of therapy is long and requires constant correction.

Symptomatic treatment is also prescribed. For example, with a decrease in gastric secretion and intestinal motility, prozerin is used.

Nervus vagus (X)

Vagus nerve, p. vagus , is a mixed nerve. Its sensory fibers end in the nucleus of the solitary pathway, the motor fibers start from the double nucleus (both nuclei are common with the glossopharyngeal nerve), and the autonomic fibers from the posterior nucleus of the vagus nerve. The vagus nerve innervates a vast territory. The fibers emerging from the autonomic nucleus make up the majority vagus nerve and provide parasympathetic innervation of the organs of the neck, chest and abdominal cavities.The fibers of the vagus nerve carry impulses that slow down the rhythm of the heartbeat, dilate blood vessels (reflexively regulate blood pressure in the vessels), narrow the bronchi, increase peristalsis and relax the intestinal sphincters, cause increased secretion of the glands of the gastrointestinal tract.

The vagus nerve emerges from the medulla oblongata in the posterior lateral groove with several roots, which, when combined, form a single trunk heading towards the jugular foramen. In the hole itself and at the exit from it, the nerve has two thickenings: the upper and lower nodes, ganglion supe- rius et ganglion inferius. These nodes are formed by the bodies of sensitive neurons. The peripheral processes of the neurons of these nodes go to the internal organs, the hard shell of the brain, the skin of the external auditory canal. In the jugular foramen, the internal branch of the accessory nerve approaches the trunk of the vagus nerve and connects with it.

After leaving the jugular foramen, the nerve goes down, located on the prevertebral plate of the cervical fascia behind and between the internal jugular vein and the internal carotid artery. The vagus nerve enters the chest cavity through the superior thoracic inlet. The right nerve is located between the subclavian artery at the back and the subclavian vein at the front. The left nerve goes between the common carotid and subclavian arteries, continuing to the anterior surface of the aortic arch (Fig. 178). Further, the right and left nerves are located behind the roots of the lungs. Then the right vagus nerve passes to the posterior, and the left - to the anterior surface of the esophagus, dividing into several branches that connect with each other. This is how the esophageal plexus is formed, from which the anterior and posterior vagus trunks are formed. The latter, together with the esophagus, pass into the abdominal cavity and there they give up their final branches.

Topographically, the vagus nerve can be divided into 4 sections: head, cervical, thoracic and abdominal.

Head office vagus nerve is located between the beginning of the nerve and the upper node. The following branches depart from this department:

1 meningeal branch, G.meningeus, departs from the upper node and goes to the hard shell of the brain in the region of the posterior cranial fossa, including the walls of the transverse and occipital sinuses.

2 ear branch, G.auricularis, starts from the lower part of the upper node, penetrates into the jugular fossa, where it enters the mastoid canal of the temporal bone. Coming out of the latter through the tympanic-mastoid fissure, the ear branch innervates the skin of the posterior wall of the external auditory canal and the skin of the outer surface of the auricle.

To cervical region the vagus nerve refers to that part of it that is located between the lower node and the outlet of the recurrent laryngeal nerve. Branches of the cervical vagus nerve:

1 pharyngeal branches, rr. pharyngei [ pharingedlis], go to the wall of the pharynx, where, connecting with the branches of the glossopharyngeal nerve and the sympathetic trunk, they form pharyngeal plexus,ple­ xus pharyngeus [ pharyngedlis]. The pharyngeal branches innervate the mucous membrane of the pharynx, the constrictor muscles, the muscles of the soft palate, with the exception of the muscle that strains the palatine curtain.

2 Superior cervical cardiac branches, rr. cardiaci cervicles superiores, in the amount of 1-3 depart from the vagus nerve, descending along the common carotid artery, and together with the branches of the sympathetic trunk enter the cardiac plexus.

3 Superior laryngeal nerve, P.laryngeus [ laryngea- lis] superior, departs from the lower node of the vagus nerve, goes forward along the lateral surface of the pharynx and at the level of the hyoid bone is divided into external and internal branches. Outer branch, Mr.externus, innervates the cricothyroid muscle of the larynx. Inner branch, Mr.internus, accompanies the superior laryngeal artery and, together with the latter, pierces the thyroid-hyoid membrane. Its terminal branches innervate the mucous membrane of the larynx above the glottis and part of the mucous membrane of the root of the tongue.

4 recurrent laryngeal nerve, P.laryngeus [ la- ringealis] recurrences, has a different origin on the right and left. The left recurrent laryngeal nerve begins at the level of the aortic arch and, having rounded it from below in the anteroposterior direction, rises vertically upwards in the groove between the esophagus and trachea. The right recurrent laryngeal nerve departs from the vagus nerve at the level of the right subclavian artery, bends around it from below and also in the posterior direction and rises up the lateral surface of the trachea. terminal branch of the recurrent laryngeal nerve inferior laryngeal nerve, p.laryngealis infe­ rior, innervates the mucous membrane of the larynx below the glottis and all the muscles of the larynx, except for the cricothyroid. Also depart from the recurrent laryngeal nerve tracheal branches,rr. trachedles, esophageal branches,rr. esophagei [ oesophagealis] and loweruieuHbieheart branches,rr. cardiaci cervicles infe- priores, that go to the heart plexus. Also departs from the lower laryngeal nerve connecting branch(with the internal laryngeal branch of the superior laryngeal nerve), G.communicants (cum r. laryngeo interno).

Thoracic- this is the section of the vagus nerve from the level of the origin of the recurrent nerves to the level of the esophageal opening of the diaphragm. Branches of the thoracic vagus nerve:

1 Thoracic cardiac branches, rr. cardiaci thordcici, are sent to the heart plexuses.

2 Bronchial "branches, / t. bronchidles, go to the root of the lung, where, together with the sympathetic nerves, they form pulmonary plexus,plexus pulmondlis, which surrounds the bronchi and with them enters the lung.

3 Esophageal plexus, plexus esophageus [ oeso­ phagealis] , is formed by the branches of the right and left vagus nerves (trunks), which are connected to each other on the surface of the esophagus. Branches extend from the plexus to the wall of the esophagus.

Abdominal The vagus nerve is represented by the anterior and posterior trunks that emerge from the esophageal plexus.

1 Front wandering trunk, truncus vagdlis anterior, passes from the anterior surface of the esophagus to the anterior surface of the stomach near its lesser curvature. From this wandering trunk depart anterior gastric branches, gg.gdstrici anteriores, as well as hepatic branches,hepdtici, running between the sheets of the lesser omentum to the liver.

2 Rear wandering trunk, truncus vagdlis pos­ interior, from the esophagus passes to the back wall of the stomach, goes along its lesser curvature, gives posterior gastric branchesrr. gdstrici posteriores, as well as celiac branches,rr. coeliaci. The celiac branches go down and back and reach the celiac plexus along the left gastric artery. The fibers of the vagus nerves, along with the sympathetic fibers of the celiac plexus, go to the liver, spleen, pancreas, kidney, small intestine and large intestine to the descending colon.