The glossopharyngeal nerve exits the skull through. IX pair - glossopharyngeal nerves

Neuralgia of the glossopharyngeal nerve is a disease characterized by a unilateral lesion of a non-inflammatory nature of the IX pair of cranial nerves. Its symptoms are similar to the manifestations of trigeminal neuralgia, and therefore there is a high probability of errors in the diagnosis. However, this pathology develops much less frequently than the last: 1 person per 200 thousand of the population falls ill with it, about 70-100 nerve lesions occur per 1 case of glossopharyngeal nerve neuralgia. Persons of mature and advanced age suffer from it, mainly men.

From our article, you will learn about why this disease occurs, what are its clinical manifestations, as well as the principles of diagnosis and treatment of glossopharyngeal neuralgia. But first, in order for the reader to understand why certain symptoms occur, we will briefly review the anatomy and functions of the IX pair of cranial nerves.

Anatomy and function of the nerve

As mentioned above, the term "glossopharyngeal nerve" (in Latin - nervus glossopharyngeus) refers to the IX pair of cranial nerves. There are two of them, left and right. Each nerve consists of motor, sensory and parasympathetic fibers, which originate in the nuclei of the medulla oblongata.

Its motor fibers provide movement of the stylo-pharyngeal muscle, which raises the pharynx.
Sensitive fibers extend into the area of the mucous membrane of the tonsils, pharynx, soft palate, tympanic cavity, auditory tube and tongue and provide sensitivity to these areas. Its gustatory fibers, being a kind of sensitive fibers, are responsible for the taste sensations of the posterior third of the tongue and epiglottis.
Together, the sensory and motor fibers of the glossopharyngeal nerve form the reflex arcs of the pharyngeal and palatine reflexes.
Parasympathetic autonomic fibers of this nerve regulate the functions of the parotid gland (responsible for salivation).

It is important to know that the glossopharyngeal nerve passes in close proximity to the vagus nerve, in connection with this, in many cases, their combined lesion is determined.

Etiology (causes) of neuralgia of the glossopharyngeal nerve

Depending on the causative factor, two forms of this pathology are distinguished: primary (or idiopathic, since its cause cannot be reliably determined) and secondary (otherwise, symptomatic).

In most cases, glossopharyngeal neuralgia occurs in the following situations:

lesions of the posterior cranial fossa (this is where the medulla oblongata is located) of an infectious nature - arachnoiditis, and others;
diseases of the endocrine system (with diabetes mellitus and so on);
in case of irritation or compression of the nerve directly in any part of it, more often in the medulla oblongata (with tumors - meningioma, hemangioblastoma, cancer in the nasopharynx and others, hemorrhages in the brain tissue, aneurysm of the carotid artery, hypertrophy of the styloid process and in a number of others situations);
in case of malignant neoplasms of the pharynx or larynx.

Also, risk factors for the development of this disease are acute viral (in particular, influenza), acute and chronic bacterial (tonsillitis, pharyngitis, otitis media, sinusitis, and others) infections and atherosclerosis.

Clinical manifestations

This pathology proceeds in the form of acute attacks of pain, which originates in the root of the tongue or one of the tonsils, and then spreads to the soft palate, pharynx and ear structures. In some cases, pain can radiate to the eye area, the angle of the lower jaw, and even to the neck. The pain is always one-sided.

Such attacks last for 1-3 minutes, provoke their movements of the tongue (during meals, loud conversation), irritation of the tonsil or the root of the tongue.

Patients are often forced to sleep exclusively on their healthy side, since in the supine position on the side of the lesion, saliva flows, and the patient is forced to swallow it in his sleep, and this provokes night attacks of neuralgia.

In addition to pain, a person is worried about dry mouth, and at the end of the attack, the release of a large amount of saliva (hypersalivation), which, however, is less on the side of the lesion than on the healthy side. In addition, the saliva secreted by the affected gland is characterized by increased viscosity.

In some patients, during a pain attack, the following symptoms may also occur:

darkening in the eyes;
lowering blood pressure;
loss of consciousness.

Most likely, such manifestations of the disease are associated with irritation of one of the branches of the glossopharyngeal nerve, which leads to inhibition of the vasomotor center in the brain, and, consequently, to a drop in pressure.

Neuralgia occurs with alternating periods of exacerbations and remissions, and the duration of the latter in some cases is up to 12 months or more. However, over time, attacks occur more often, remissions become shorter, and the pain syndrome also becomes more intense. In some cases, the pain is so severe that the patient groans or screams, opens his mouth wide and actively rubs his neck at the angle of the lower jaw (the pharynx is located under the soft tissues of this area, which, in fact, hurts).

Patients with experience often complain of pain not of a periodic, but of a permanent nature, which become stronger when chewing, swallowing, talking. Also, they may have a violation (decrease) of sensitivity in areas innervated by the glossopharyngeal nerve: in the posterior third of the tongue, tonsil, pharynx, soft palate and ear, taste disturbance in the region of the root of the tongue, and a decrease in the amount of saliva. With symptomatic neuralgia, sensitivity disorders progress over time.

The consequence of violations of sensitivity in some cases are difficulties in chewing food and swallowing it.

Diagnostic principles

The primary diagnosis of neuralgia of the glossopharyngeal nerve is based on the doctor's collection of patient complaints, anamnesis data of his life and current disease. Everything matters: localization, the nature of the pain, when it occurs, how long the attack lasts and how it ends, how the patient feels in the period between attacks, other symptoms that disturb the patient (they may indicate a pathology - a potential cause of neuralgia), concomitant neurological diseases. , endocrine, infectious or other nature.

Then the doctor will conduct an objective examination of the patient, during which he will not reveal any significant changes in his condition. Unless pain can be detected when probing (palpation) of soft tissues above the angle of the lower jaw and in certain areas of the external auditory canal. Often, in such patients, the pharyngeal and palatine reflexes are reduced, the mobility of the soft palate is impaired, sensitivity disorders of the posterior third of the tongue are determined (the patient feels all tastes are bitter). All changes are not bilateral, but are found only on one side.

To establish the causes of secondary neuralgia, the doctor will refer the patient for additional examination, which will include some of these methods:

echoencephalography;
computer or magnetic resonance imaging of the brain;
consultation of related specialists (in particular, an oculist, with a mandatory examination of the fundus - ophthalmoscopy).

Differential Diagnosis

Some diseases occur with symptoms similar to those of glossopharyngeal neuralgia. In each case of a patient’s treatment with such signs, the doctor conducts a thorough differential diagnosis, because the nature of these pathologies is different, which means that the treatment has its own characteristics. So, pain attacks in the face are accompanied by such diseases:

trigeminal neuralgia (much more common than others);
ganglionitis (inflammation of the nerve ganglion) of the pterygopalatine node;
neuralgia of the ear node;
different nature of glossalgia (pain in the language area);
Oppenheim's syndrome;
neoplasms in the pharynx;
pharyngeal abscess.

Treatment tactics

As a rule, neuralgia of the glossopharyngeal nerve is treated conservatively, combining medication and physiotherapy for patients. Sometimes it is not possible to do without surgery.

Medical treatment

The leading goal of treatment in this situation is the elimination, or at least a significant relief of the pain that torments the patient. For this apply:

local anesthesia preparations (dikain, lidocaine) on the root of the tongue;
injectable local anesthetics (novocaine) - when topical agents do not have the desired effect; the injection is carried out directly into the root of the tongue;
non-narcotic analgesics (non-steroidal anti-inflammatory drugs) for oral administration or injection: ibuprofen, diclofenac and others.

The patient may also be prescribed:

group B vitamins (milgamma, neurobion and others) in the form of tablets and injections;
(finlepsin, difenin, carbamazepine, and so on) in tablets;
(in particular, chlorpromazine) for injection;
multivitamin complexes (Complivit and others);
drugs that stimulate the body's defenses (ATP, FiBS, ginseng preparations and others).

Physiotherapy

Physiotherapy techniques play an important role in the complex treatment of neuralgia of the glossopharyngeal nerve. They are carried out in order to:

reduce the intensity of pain attacks and their frequency;
improve blood flow in the affected area;
improve tissue nutrition in areas innervated by this nerve.

The patient is prescribed:

fluctuating currents to the upper sympathetic nodes (more precisely, to the area of their projection); the first electrode is placed 2 cm back from the angle of the lower jaw, the second - 2 cm above this anatomical formation; apply current with force until the patient feels moderate vibration; the duration of such exposure is usually from 5 to 8 minutes; procedures are carried out every day in a course of 8-10 sessions; the course of treatment is repeated 2-3 times in 2-3 weeks;
sinusoidal modulated currents on the projection area of the cervical sympathetic nodes (an indifferent electrode is placed on the back of the patient's head, and bifurcated electrodes are placed on the sternocleidomastoid muscles; the session lasts 8-10 minutes, the procedures are carried out 1 time per day, with a course of up to 10 exposures, which is repeated three times with an interval of 2 -3 weeks);
ultrasound therapy or ultraphonophoresis of painkillers (in particular, analgin, anesthesin) drugs or aminophylline; affect the occipital region, on both sides of the spine; the session lasts 10 minutes, they are carried out 1 time in 1-2 days with a course of 10 procedures;
drug electrophoresis of gangleron paravertebral on the cervical and upper thoracic vertebrae; the duration of the session is from 10 to 15 minutes, they are repeated daily, in a course of 10-15 exposures;
magnetotherapy with an alternating magnetic field; use the apparatus "Pole-1", act through a rectangular inductor on the vertebrae of the cervical and upper thoracic spine; session duration - 15-25 minutes, they are carried out once a day with a course of 10 to 20 procedures;
decimeter wave therapy (they act through the rectangular emitter of the Volna-2 device on the collar area of the patient; the air gap is 3-4 cm; the procedure lasts up to 10 minutes, they are repeated 1 time in 1-2 days with a course of 12-15 sessions);
laser puncture (they act on the biological points of the IX pair of cranial nerves, the exposure is up to 5 minutes per 1 point, the procedures are carried out every day with a course of 10 to 15 sessions);
therapeutic massage of the cervical-collar zone (performed daily, the course of treatment includes 10-12 procedures).

Surgery

In some situations, in particular, with hypertrophy of the styloid process, one cannot do without surgical intervention in the amount of resection of a part of this anatomical formation. The purpose of the operation is to eliminate compression of the nerve from the outside or irritation by its surrounding tissues.

Conclusion

Neuralgia of the glossopharyngeal nerve, although it happens quite rarely, is capable of delivering real torment to a person suffering from it. The disease can be idiopathic (primary) and symptomatic (secondary). It is manifested by bouts of pain in the zones of innervation of the IX pair of cranial nerves, pre-syncope. It proceeds with alternating exacerbation and remission, but over time, attacks occur more and more often, pain becomes more intense, and remissions become shorter and shorter. It is important to correctly diagnose this pathology, since in some cases it is a manifestation of serious diseases that require urgent treatment.

Treatment of neuralgia itself may include the patient taking medications, physiotherapy, or surgery (fortunately, it is needed relatively rarely).

The prognosis for recovery from this pathology is usually favorable. Nevertheless, its treatment is long, stubborn: it lasts up to 2-3 years and even longer.

Channel One, the program “Live Healthy” with Elena Malysheva, the heading “About Medicine” on the topic “Neuralgia of the glossopharyngeal nerve”:

Neuralgia is a pain syndrome at the site of nerve passage. Depending on the location of the nerve ending, neuralgia also has different names. So, for example, in the presence of pain, which is characterized by periodic "shoots" in the back of the head and symptoms of migraine, a disease such as occipital neuralgia should be suspected.

A distinctive characteristic of neuralgia from neuritis is the absence of an inflammatory reaction. Among neuritis, the nerve endings that pass on the face and hands, for example, and trigeminal with classic symptoms, most often suffer.

Symptoms of neuralgia of the glossopharyngeal nerve are largely due to its structure, since this nerve has sensory, motor and parasympathetic fibers. The former are responsible for the perception of the soft palate, pharynx, tonsils, taste qualities of the proximal part of the tongue and epiglottis. As for the motor bundle, it controls the process of swallowing in the form of a pharyngeal reflex, and the work of the stylo-pharyngeal muscle. In turn, parasympathetic influence is observed in the regulation of the process of salivation.

Symptoms of neuralgia of the glossopharyngeal nerve are in many ways similar to neuralgia of the facial nerve. They are characterized by paroxysmal pains on one side of the root of the tongue, oropharynx and soft palate, especially during the use of irritating solid food (hot or cold), as well as during communication, coughing or yawning. The center of neuralgia, where signals about nerve damage are received, is located in the brain and spinal cord.

The prevalence of the disease is quite low, the number of cases is increasing due to the male population. In most cases, neuralgia begins to bother after 40 years.

Causes of neuralgia of the glossopharyngeal nerve

Neuralgia can manifest itself as an independent disease or as symptoms or complications of another pathology. Causal factors include:

Taking into account the causes of the disease, the treatment of glossopharyngeal neuralgia also has its own characteristics. Sometimes you can do with conservative methods, but some cases require surgical intervention, without which recovery will not occur.

Clinical symptoms of neuralgia

The disease can manifest itself acutely with an increase in pain. A characteristic feature of pain is a tendency to and paroxysmal flow. The pain starts from the root of the tongue or in the tonsils. Further it extends to the palate, oropharynx and ear. In addition, pain can be observed in the corner of the lower jaw, eye or neck area.

Each attack is rather short and lasts approximately 2-3 minutes. The pain syndrome affects only one side. In addition to pain, a person feels dryness in the oral cavity, which is replaced by increased secretion of saliva after an attack.

When probing, unpleasant pain is observed in the region of the angle of the lower jaw, as well as in some parts of the external part of the auditory canal. This is especially pronounced during the attack. Sometimes the pharyngeal reflex may be inhibited and the mobility of the soft palate may decrease, which makes it impossible to swallow saliva, water or food. With regard to taste sensitivity, there is a perception of all food with a bitter aftertaste.

The course of the disease can take place with remissions and exacerbations. Symptoms of neuralgia of the glossopharyngeal nerve can be constantly disturbing in the form of a burning and supporting character near the root of the tongue or increase in intensity under the influence of any provoking factor, such as coughing or a normal meal. In addition, the affected side of the face may acquire a hyperemic hue, and the cough that often occurs is the result of a sensation in the throat of a foreign body.

In addition to local clinical manifestations, there are also general symptoms of glossopharyngeal neuralgia. Among them, it is necessary to focus on a decrease in systemic blood pressure, impaired conduction of a nerve impulse through the heart muscle with the onset of arrhythmia and other rhythm changes, as well as weakness in the muscles of the limbs and frequent loss of consciousness.

Exacerbation of the disease often occurs during periods of low air temperatures (autumn, winter), which is replaced by remissions. Thus, the neuralgia of the glossopharyngeal nerve is characterized by seasonality.

An attack of a painful attack can be provoked by exposure to certain structures of the oral cavity. Irritating them, there is an increase in the intensity of the pain syndrome. These areas are located on the palatine tonsils, arches and root of the tongue. During the period of remission, increased salivation may be observed.

Differential diagnosis of neuralgia of the glossopharyngeal nerve

Symptoms of glossopharyngeal neuralgia are for the most part similar to clinical manifestations of ganglionitis of the nodes of this nerve. The only evidence of ganglionitis is the presence of herpetic vesicles in the pharynx and pharynx.

In addition, do not forget about neuralgia of the facial nerve, which can also be manifested by pain on one side of the face, short attacks and impaired swallowing. The difference is the location of trigger points on the face in the area of the lips, and in the case of neuralgia of the glossopharyngeal nerve, these zones are localized at the root of the tongue.

After analyzing the clinical picture and anamnesis of the disease, additional instrumental diagnostic methods are used to more accurately determine the cause of the disease:

x-ray study. It can be used to detect hypertrophy of the styloid process or ossification of the stylohyoid ligament;
computer diagnostics of the brain allows you to detect pathology in bone structures;
magnetic resonance imaging provides visualization of pathological processes in soft tissues;
electroneuromyography is necessary to register violations of the conduction of nerve impulses.

Therapeutic measures for neuralgia of the glossopharyngeal nerve

Treatment of glossopharyngeal neuralgia consists in reducing the intensity or even eliminating the pain syndrome. For this purpose, a solution of dicaine or other anesthetics applied to the root of the tongue is used. This manipulation ensures the absence of pain for 6-7 hours.

With inefficiency or a shorter pain-free period, it is recommended to use novocaine injection. For one injection, 2 to 5 ml of a 1-2% solution may be required. The injection site is located on the root of the tongue. In addition, it is allowed to use novocaine or with the help of trichlorethyl blockades at the site of carotid branching.

In addition to injection methods to combat pain, non-narcotic analgesics are widely used for oral administration.

Of the physiotherapeutic methods, diadynamic and sinusoidal modulated currents are recommended. The point of their application is the area behind the jaw, tonsil and oropharynx. The course of galvanization is carried out using an anode located at the root of the tongue, and a cathode behind the jaw.

General therapeutic measures include the use of B vitamins, antipsychotics (chlorpromazine) for intramuscular administration, as well as antiepileptic drugs (difenin, finlepsin and carbomazepine - for oral administration.

To increase the immune defenses, vitamins, aloe extract, ginseng, ATP and many other restorative drugs should be used.

If the cause of neuralgia is an enlarged styloid process, then the treatment consists in surgical intervention, which involves its resection. In case of inefficiency, it is necessary to resort to radicotomy, the level of which is located on the posterior cranial fossa, or to tracotomy and chordotomy.

Surgical treatment is based on the release of the nerve from compression and irritating influence of surrounding tissues. For this, microscopic endoscopic equipment is used, which ensures a minimal risk of complications. With its help, the squeezing factor is removed near the exit from the brain stem.

Treatment of the disease takes a rather long period of time, which can drag on for several years, but when using an integrated approach, complete recovery occurs.

The glossopharyngeal nerve (n. glossopharyngeus) is part of the IX pair of cranial nerves. Consists of different types of fibers: parasympathetic, motor and sensory.

Anatomy of the glossopharyngeal nerve

The nerve leaves the medulla oblongata usually 4-6 roots behind the inferior olive near the tenth and eleventh nerves. Gathering into one single nerve, they leave the skull through the jugular foramen, at this point the tympanic nerve separates from the main trunk.

In the opening, the glossopharyngeal nerve thickens a little, forms the upper node, immediately after the exit - the lower node. The first sensitive neurons are located in them and impulses from them are sent to the nucleus, which is responsible for sensitivity.

Next, the nerve descends to the internal carotid artery, passes between it and the internal jugular vein, makes a bend in the shape of an arc, after which it gives one of its branches to the place where the carotid artery divides, namely to the carotid sinus. After separation of the sinus branch, it moves to the pharynx, where it begins to branch and gives off several branches:

Pharyngeal two or three small branches
Tonsil - conduct impulses from the soft palate, tonsils
Lingual - three or four, they provide taste sensations, general sensitivity from the back third of the tongue

The motor part of the nerve innervates the stylo-pharyngeal muscle.

Parasympathetic fibers: small stony nerve reaches the ear node, then postganglionic fibers pass into the parotid salivary gland, which they innervate.

In the screenshot below, we see 3 pairs of nuclei of the glossopharyngeal nerve. They are all marked with different colors.

The inferior salivary nucleus (highlighted in yellow) is parasympathetic.

Green marks the core of the single path. It is responsible for the sensation of taste in the back third of the tongue. Taste information is sent from the nucleus to the thalamus. The fact that this nucleus is responsible for taste sensitivity, scientists learned at the end of the 19th century.

For simplicity, we can say that the fibers of the ninth nerve connect to the middle part of the nucleus. Whereas the fibers of the seventh nerve occupy the upper third, and the tenth - the lower.

Double nucleus, marked in pink - motor. Also, the fibers of the tenth and eleventh nerves originate from it. Central motor neurons are located in the lower parts of the precentral gyrus.

Interesting fact: there is evidence that the fourth nucleus is determined - the spinal nucleus of the trigeminal nerve - and it is responsible for general sensitivity from areas such as the soft palate, throat, auditory tube and tympanic cavity. Usually it is not indicated, since very few axons go to it.

Functions of the glossopharyngeal nerve

Although it is mixed, one of the most important functions will be to provide taste recognition, to be more precise - salty and bitter, from the back third of the tongue. This is one of the first signs, which is very helpful if you suspect a malfunction of the ninth nerve.

The second serious task is the transmission of impulses of general sensitivity from zones where sensitive branches fit.

Vegetative fibers ensure adequate functioning of the secretory function of the parotid salivary gland.

A small portion of motor fibers provides innervation to the stylogharyngeal muscle, which raises the pharynx during swallowing.

Glossopharyngeal nerve lesions

Symptoms

One of the first symptoms is a loss of general sensitivity in the innervated zones, a change in the understanding of the position of the tongue in the oral cavity is possible, which interferes with the normal capture and chewing of food. The definition of the taste qualities of food, namely salty and bitter, also suffers (these taste detection zones are located in the area just in the last third of the tongue). It appears only if there has been a violation in the nerve itself or the core responsible for the perception of taste has suffered.

It should be said that a decrease in taste perception is also possible due to diseases of the tonsils, the presence of a dense coating on the tongue, so you need to pay attention to the condition of the tongue and oral cavity when we determine the taste. It's also important to be aware of a person's chronic illnesses and medications (especially antibiotics) they're taking, because that can also affect the sense of taste.

In the presence of a pathological process that irritates the IX cranial nerve, there is sometimes constant or paroxysmal soreness in the throat, back of the tongue, posterior pharyngeal wall, Eustachian tube, middle ear.

An interesting fact: there is a separate syndrome of neuralgia of the glossopharyngeal nerve or Sikaro-Rabino syndrome. It is characterized by acute paroxysmal soreness from the tonsil or at the root of the tongue, which radiates to the ear, neck, or lower jaw. These attacks can appear when swallowing, taking cold or hot food.

A slight dryness in the mouth may occur, but this is not a reliable and not permanent sign, because the weak function of one salivary gland can be replaced by the work of others.

Another sign of damage to the glossopharyngeal nerve is weakness when checking the palatine and pharyngeal reflex on the side of the lesion. Be sure to remember that the IX and X pairs are very closely connected, which means that when checking the above reflexes, revealing their weakness, you need to think not only about the glossopharyngeal nerve, but also remember about the vagus.

Test: alternately different types of solutions are dripped: sweet, salty, sour and bitter - on symmetrical sections of the surface of the tongue separately in each of its thirds. Substances are applied using a pipette or moistened filter paper. Fluid should not be allowed to spread over the mucous membrane. After each solution, rinse your mouth thoroughly for more accurate test results.

Treatment of the glossopharyngeal nerve

To treat a malfunction of this nerve, it is necessary to find out the root cause that causes the appearance of certain symptoms. Perhaps this is a kink and compression of the nerve root by a crowded inferior cerebellar or vertebral artery, the presence of inflammatory, tumor formations, as well as aneurysms in the skull where the glossopharyngeal nerve comes to the surface.

Glossopharyngeal nerve, n. glossopharyngeus (IX pair) mixed in nature.

It contains sensory, motor and parasympathetic secretory fibers.

Fibers of different nature are axons of different nuclei, and some nuclei are common with the vagus nerve.

The nuclei of the glossopharyngeal nerve lie in the posterior sections of the medulla oblongata. Isolate the sensitive nucleus of the solitary pathway, nucleus tractus solitarius; motor double core ,nucleus ambiguus; parasympathetic (secretory) lower salivary nucleus, nucleus salivatorius inferior.

On the surface of the rhomboid fossa, these nuclei are projected in the posterior part of the medulla oblongata: the motor nucleus - in the region of the triangle of the vagus nerve; sensitive core - outward from the border furrow; the vegetative nucleus - respectively, the border furrow, medial to the double nucleus.

The glossopharyngeal nerve appears on the lower surface of the brain with 4-6 roots behind the olive, below the VIII pair. It travels outward and forward and exits the skull through the anterior jugular foramen. In the region of the opening, the nerve thickens somewhat due to the upper node located here, the ganglion rostralis (superius).

Having exited through the jugular foramen, the nerve thickens again due to the lower node, the ganglion caudalis (inferius), which lies in a stony fossa on the lower surface of the temporal bone pyramid.

Sensitive (afferent) fibers are processes of the cells of the upper and lower nodes of the glossopharyngeal nerve, and the peripheral ones follow as part of the nerve to the organs, and the central ones form a single path, around which the nerve cells are assembled into the nucleus of a single path (sensitive). Part of the fibers passes to the upper part of the posterior nucleus of the vagus nerve.

Motor (efferent) fibers are axons of nerve cells of the somatic double nucleus, which lies in the back of the medulla oblongata. These fibers make up the nerve to the stylopharyngeal muscle.

Parasympathetic (secretory) fibers originate in the vegetative lower salivary nucleus, nucleus salivatorius caudalis (inferior), which lies somewhat anteriorly and medially to the somatic double nucleus.

From the base of the skull, the glossopharyngeal nerve goes down, goes between the internal carotid artery and the internal jugular vein, forming an arc, follows forward, slightly up and enters the thickness of the root of the tongue.

In its course, the glossopharyngeal nerve gives off a number of branches.

I. Branches starting from the bottom node:

Tympanic nerve, n. tympanicus, in its composition is afferent and parasympathetic. It departs from the lower node of the glossopharyngeal nerve, enters the tympanic cavity and goes along its medial wall. Here the tympanic nerve forms a small tympanic thickening (knot), intumescentia (ganglion) tympanica, and then splits into branches, which in the mucous membrane of the middle ear make up the tympanic plexus, plexus tympanicus.

The next section of the nerve, which is a continuation of the tympanic plexus, exits the tympanic cavity through a cleft canal of the small stony nerve called the small stony nerve, n. petrosus minor. The connecting branch from the large stony nerve approaches the latter. Leaving the cranial cavity through the sphenoid-stony fissure, the nerve approaches the ear node, where the parasympathetic fibers switch.

All three departments: the tympanic nerve, the tympanic plexus, and the small petrosal nerve, connect the lower node of the glossopharyngeal nerve with the ear node.
The tympanic nerve or tympanic plexus has connections with the facial nerve (with its branch - the greater petrosal nerve) and with the sympathetic plexus of the internal carotid artery through the carotid nerves, nn. caroticotympanici.

The tympanic nerve gives off the following branches:

1) pipe branch, r. tubarius, to the mucous membrane of the auditory tube;

2) connecting branch with the auricular branch of the vagus nerve, r. communicants(cum ramo auriculi n. vagi).

In addition, there are 2-3 thin tympanic branches to the mucous membrane covering the tympanic membrane from the side of the tympanic cavity, and to the cells of the mastoid process, as well as small branches to the vestibule window and the cochlear window.

II. Branches originating from the trunk of the glossopharyngeal nerve:

1 . pharyngeal branches, rr. pharyngei, - these are 3-4 nerves, start from the trunk of the glossopharyngeal nerve where the latter passes between the external and internal carotid arteries. The branches go to the lateral surface of the pharynx, where, connecting with the branches of the same name of the vagus nerve (branches from the sympathetic trunk also fit here), they form the pharyngeal plexus, plexus pharyngeus.

2 . sinus branch, r. sinus carotid, one or two thin branches, enter the wall of the carotid sinus and into the thickness of the carotid glomus.

3 . Branch of the stylo-pharyngeal muscle r. musculi stylopharyngei, goes to the corresponding muscle and enters into it with several branches.

4 . almond branches, rr. tonsillares, depart from the main trunk with 3-5 branches in the place where it passes near the tonsil. These branches are short, go up and reach the mucous membrane of the palatine arches and tonsils.

5 . lingual branches, rr. linguales, are terminal branches of the glossopharyngeal nerve. They pierce the thickness of the root of the tongue and are divided in it into thinner, interconnected branches. The terminal branches of these nerves, which carry both taste fibers and fibers of general sensitivity, end in the mucous membrane of the posterior third of the tongue, occupying the area from the anterior surface of the epiglottic cartilage to the trough papillae of the tongue, inclusive.

Before reaching the mucous membrane, these branches are connected along the midline of the tongue with the branches of the same name on the opposite side, as well as with the branches of the lingual nerve (from the trigeminal nerve).

Sensitive fibers of the glossopharyngeal nerve, ending in the mucous membrane of the posterior third of the tongue, conduct taste stimuli through the peripheral nodes of the glossopharyngeal nerve to the nucleus of the solitary tract.

Taste irritations of the fibers of the intermediate nerve (string drum) and the vagus nerve also come here. Further stimulation reaches the thalamus and is believed to reach the region of the hook.

ear node,ganglion oticum, located on the medial side of the mandibular nerve immediately after the exit of the latter from the foramen ovale. The preganglionic parasympathetic fibers approach the ear node as part of the small stony nerve (see p. 416).

4. Lingual nerve, n. lingualis, - the mixed nerve goes down between the external and internal pterygoid muscles, and then, bending in an arc, goes forward and down (Fig. 176). Passing along the inner surface of the lower jaw,

Rice. 176. Nerves of the head and neck; left view. (Muscles, vessels, lateral wall of the base of the skull and the left half of the lower jaw are removed.) 1 - gangl. trigeminale; 2 - n. glossopharyngeus; 3 - n. accessorius; 4 - n. vagus; 5 - gangl. cervicale superius; 6 - plexus cervicalis; 7-n. laryn "gealis inferior; 8 - ansa cervicalis; 9 - n. laryngealis superior; 10 - n. hypoglossus-11 - n. lingualis.

under the mucous membrane of the floor of the mouth, enters the lower part of the tongue. The nerve is formed by fibers that conduct general sensitivity (pain, touch, temperature) from the mucous membrane of the anterior two-thirds of the tongue (lingual branches,rr. lin- guales), mucous membrane of the lower part of the oral cavity and the anterior parts of the lower gum (hyoid nerve, p.sublingudlis) , palatoglossal arch and palatine tonsil (branches of the isthmuspharynx,rr. isthmi fducium).

Also depart from the lingual nerve nodal branches,rr. ganglio- nares, containing sensitive, as well as preganglionic parasympathetic fibers. Nodal branches are attached to submandibular node,ganglion submandibulare, and sublingualknot,ganglion sublinguale. Preganglionic parasympathetic fibers that run as part of the lingual nerve [see. "Parasympathetic part of the autonomic (vegetative) nervous system"], join the lingual nerve in the form connecting branch(with drum string)r. communicants (cum chorda tympani), which is a branch of the facial nerve. The drum string merges -

Xia with the lingual nerve in the place where it passes between the medial and lateral pterygoid muscles. In addition to pre-ganglionic parasympathetic fibers, taste fibers that go as part of the tympanic string join the lingual nerve.

5. Inferior alveolar nerve, P.alveolaris inferior, - mixed, the largest of all branches of the mandibular nerve, adjacent to the outer surface of the lateral pterygoid muscle, contains sensory and motor fibers. The nerve enters the mandibular canal through its opening and, having passed through the canal, exits it through the mental foramen as mental nerve, p.mentalis. At the point of entry of the lower alveolar nerve into the mandibular canal, a motor portion departs from it - the maxillary-hyoid nerve, which innervates the maxillo-hyoid muscle and the anterior belly of the digastric muscle. In the mandibular canal, branches depart from the inferior alveolar nerve, which, connecting with each other, form lower dental plexusplexus dentalis inferior. From this plexus come lower dentalbranches,rr. dentales inferiores, and lower gingival branchesrr. gingi- vales inferiores, for the innervation of the teeth of the lower jaw and gums. The terminal branch of the inferior alveolar nerve is the mental nerve, P.mentalis, ends in the skin of the chin and lower lip, giving to them chin and lower labialsbranches,rr. mentales et labiales inferiores, a also branches to the gums,rr. gingivales.

abducens nerve (VI)

Abducens nerve, p. abducens , formed by the axons of the motor cells of the nucleus of this nerve, which lies in the cover of the bridge. The nerve leaves the substance of the brain in the groove between the pons and the medulla oblongata, pierces the dura mater of the brain and passes in the cavernous sinus to the side of the internal carotid artery, and then through the superior orbital fissure enters the orbit. The abducens nerve innervates the lateral rectus muscle of the eye.

Review questions

Name the branches of the trigeminal nerve. Where (to what area of the head) does each of the branches go?

What nerves formed in the orbit from the first branch of the trigeminal nerve contain autonomic parasympathetic fibers? Where do these fibers come from and where do they go?

List the branches that originate from the infraorbital nerve. Which branches originate from the pterygopalatine node and where does each of these branches go?

What muscles are innervated by branches of the mandibular nerve? List the sensory branches of this nerve.

Where do the parasympathetic fibers go that join as part of the tympanic string to the lingual nerve?

facial nerve (VII)

Facial nerve, p. facialis (Fig. 177), unites two nerves of the facial nerve proper, P.facialis, formed by motor nerve fibers - processes of cells of the nucleus of the facial nerve, and the intermediate nerve, P.interme dius, containing sensitive taste and autonomic (parasympathetic) nerve fibers. Sensory fibers end on the cells of the nucleus of the solitary pathway, motor fibers start from the motor nucleus, and vegetative fibers from the superior salivary nucleus. The nuclei of the facial nerve lie within the pons of the brain.

Coming to the base of the brain at the posterior edge of the bridge, lateral from the olive, the facial nerve, together with the intermediate and vestibulocochlear nerves, enters the internal auditory meatus. In the thickness of the temporal bone, the facial nerve passes through the facial canal and exits the temporal bone through the stylomastoid foramen. In the place where there is a knee of the facial canal, the facial nerve forms a bend - knee,geniculum, and knee knot,ganglion geniculi. The knee node refers to the sensitive part of the facial (intermediate) nerve and is formed by the bodies of pseudo-unipolar neurons.

In the facial canal, the following branches depart from the facial nerve: 1. Large stony nerve, P.petrosus major, formed by preganglionic parasympathetic fibers, which are processes of cells of the superior salivary nucleus. This nerve originates from the facial in the region of the knee and exits to the anterior surface of the pyramid of the temporal bone through the cleft of the canal of the large stony nerve. Having passed along the sulcus of the same name, and then through the torn hole, the large stony nerve enters the pterygoid canal and, together with the sympathetic nerve, from the internal carotid plexus [glulateral petrosal nerve, n.petrosus profundus (BNA)] is called nerve of the pterygoid canal, n.canalis pterygoidei, and as part of the latter, it approaches the pterygopalatine ganglion (see "Trigeminal nerve").

2. Drum string, chorda tympani, It is formed by preganglionic parasympathetic fibers coming from the superior salivary nucleus, and sensitive (gustatory) fibers, which are peripheral processes of pseudo-unipolar cells of the knee node. The fibers originate on taste buds located in the mucosa of the anterior two-thirds of the tongue and soft palate. The tympanic string departs from the facial nerve before it exits the stylomastoid foramen, passes through the tympanic cavity without giving off branches there, and leaves it through the tympanic fissure. The tympanic string then travels forward and downward and joins the lingual nerve.

3. Stapes nerve, P.stapedius, departs from the facial

Rice. 177. Superficial nerves of the head and neck.

1-rr. temporales; 2 - n. supraorbitalis; 3-rr. zygomatici; 4 - n. infraor-bitalis; 5-r. buccalis; 6 - n. facialis; 7 - n. mentalis; 8-r. marginalis mandibulae; 9-r. colli; 10-n. transverse colli; 11-nn. supraclaviculares; 12-n. accessorius; 13 - n. auricularis magnus; 14 - n. occipitalis minor; 15 - n. occipitalis major; 16 - n. auriculotemporalis.

th nerve and innervates the stapedius muscle. After exiting the stylomastoid foramen, the facial nerve gives motor branches to the posterior belly of the supracranial muscle, to the posterior auricular muscle - the posterior auricular nerve, P.auricularis post rior, and to the posterior belly of the digastric muscle - digastricbranch,r. digastricus, to stylohyoid muscle - awl-hyoid branch, d.stylohyoideus. Then the facial nerve enters the parotid salivary gland and in its thickness is divided into a number of branches that connect with each other and form such a

parotid plexus at once, plexus parotideus [ intra- parotideus]. This plexus consists only of motor fibers. Branches of the parotid plexus:

1) temporal branches,rr. temporales, go up to the temporal region and innervate the ear muscle, the frontal belly of the supracranial muscle and the circular muscle of the eye;

zygomatic branches,rr. zygomdtici, go anteriorly and upward, innervate the circular muscle of the eye and the large zygomatic muscle;

buccal branches,rr. buccales, they go forward along the surface of the chewing muscle and innervate the large and small zygomatic muscles, the muscle that lifts the upper lip, and the muscle that raises the angle of the mouth, the cheek muscle, the circular muscle of the mouth, the nasal muscle, the muscles of laughter;

marginal branch of the lower jaw,r. margindlis mandibulae [ mandibuldris], goes down and forward along the body of the lower jaw, innervates the muscles that lower the lower lip and corner of the mouth, as well as the chin muscle;

neck branch,r. witholli, goes behind the angle of the lower jaw down the neck to the subcutaneous muscle of the neck, connects with the transverse nerve of the neck from the cervical plexus.

Review questions

Name the branches of the facial nerve. Which of these branches extend from the main trunk of the nerve in the thickness of the pyramid of the temporal bone?

What fibers make up the greater petrosal nerve? Where does this nerve originate, where does it go?

What impulses does the drum string carry? Where does it start and where does it go?

What motor branches originate from the facial nerve? What is the name of each of them and what muscles innervates?

Vestibulocochlear nerve(VIII)

Vestibulocochlear nerve, n. vestibulocochlearis , formed

sensitive nerve fibers coming from the organ of hearing and balance. On the anterior surface of the brain, the vestibulocochlear nerve emerges behind the pons, lateral to the facial nerve root. Then the nerve enters the internal auditory canal and is divided into the vestibular and cochlear parts, respectively, by the presence of the vestibular and cochlear nodes (see "Inner ear").

The bodies of the nerve cells that make up front part,pars I neruus] vestibuldris, vestibulocochlear nerve, lie in vestibular node,ganglion vestibulare, which is located at the bottom of the internal auditory canal. The peripheral processes of these cells form anterior, posterior and lateral ampulla-nye nerves, pp.ampulldres anterior, posterior et later alis, as well as elliptical-saccular-ampullar nerve, p.utriculoampullaris, and spherical saccular nerve, p.saccularis, which finish-414

are receptors in the membranous labyrinth of the inner ear. The central processes of the cells of the vestibular node are sent to the nuclei of the same name, which lie in the region of the vestibular field of the rhomboid fossa, forming the vestibular part of the vestibulocochlear nerve.

cochlear part,pars (nervus) cochlearis, vestibulocochlear nerve is formed by the central processes of neurons cochlear node(spiral knot of the cochlea), ganglion cochleare (ganglion spirale cochleae), lying in the spiral canal of the cochlea. The peripheral processes of the cells of this node end in the spiral organ of the cochlear duct, and the central processes reach the cochlear nuclei that lie in the pons operculum and project into the vestibular field of the rhomboid fossa [see Fig. "The vestibulocochlear organ (the organ of hearing and balance)"].

Glossopharyngeal nerve (IX)

glossopharyngeal nerve, P.glossopharyngeus, is a mixed nerve and is formed by sensory, motor and secretory (parasympathetic) fibers (see Fig. 176). Sensitive nerve fibers end on the cells of the nucleus of the solitary pathway, motor fibers start from the double nucleus, and vegetative fibers from the lower salivary nucleus.

The glossopharyngeal nerve leaves the medulla oblongata 4-5 roots behind the olive next to the roots of the vagus and accessory nerves and, together with these nerves, goes to the jugular foramen. In the jugular foramen, the nerve thickens, forms a small sensitive top node,ganglion superius, and at the exit from this hole in the area of the stony fossa there is a larger bottom node,gangli on inferius. These nodes contain the cell bodies of sensory neurons. The central processes of the cells of these nodes are sent to the medulla oblongata to the sensitive nucleus of the glossopharyngeal nerve (the nucleus of the solitary pathway), and the peripheral processes as part of its branches follow the mucous membrane of the posterior third of the tongue, to the mucous membrane of the pharynx, middle ear, to the carotid sinus and glomerulus. After leaving the jugular foramen, the nerve passes behind the internal carotid artery, and then passes to its lateral surface, located between this artery and the internal jugular vein. Further, arcuately curving, the nerve goes down and forward between the stylo-pharyngeal and stylo-lingual muscles and penetrates the root of the tongue, where it divides into terminal lingualbranches,rr. linguales. The latter go to the mucous membrane of the posterior third of the back of the tongue.

The following lateral branches depart from the glossopharyngeal nerve:

1. Tympanic nerve, P.tympdicus, exits the lower node of the glossopharyngeal nerve and goes to the tympanic canaliculus of the temporal bone through the lower opening of this canaliculus. Entering through the tubule and tympanic cavity, the nerve divides into

branches that form in the mucous membrane tympanic plexus,plexus tympanicus. Also suitable for the tympanic plexus carotid-tympanic nerves, pp.caroticotympanici, from the sympathetic plexus on the internal carotid artery. From the tympanic plexus to the mucous membrane of the tympanic cavity and the auditory tube departs sensitive pipe branch,r. tubaris [ tubdrlus]. The terminal branch of the tympanic nerve is the small stony nerve, P.petrosis minor, containing preganglionic parasympathetic fibers, exits the tympanic cavity to the anterior surface of the temporal bone pyramid through the cleft of the small stony nerve, passes along the sulcus of the same name, then exits the cranial cavity through the torn opening and enters the ear node.

2. Sinus branch, r . sinus carotici, goes down to the bifurcation of the common carotid artery, where it innervates the carotid sinus and carotid glomerulus.

pharyngeal branches, rr. pharyngei [ pharyngeales] , go to the lateral wall of the pharynx, where, together with the branches of the vagus nerve and the branches of the sympathetic trunk, they form the pharyngeal plexus.

Branch of shilogl o precise muscle, r . muscuii style- pharyngei, motor, goes forward and innervates the stylo-pharyngeal muscle.

almond branches, rr. tonsillares, separated from the glossopharyngeal nerve before entering the root of the tongue and sent to the mucous membrane of the palatine arches and palatine tonsils.

Connecting branch (with auricular branch of the vagus nerve), r . comm" iimcans (cum ramo auriculari nervous vagi), joins the ear branch of the vagus nerve.

Nervus vagus (X)

Vagus nerve, p. vagus , is a mixed nerve. Its sensory fibers end in the nucleus of the solitary tract, the motor fibers start from the double nucleus (both nuclei are common with the glossopharyngeal nerve), and the autonomic fibers start from the posterior nucleus of the vagus nerve. The vagus nerve innervates a wide area. The fibers emerging from the autonomic nucleus make up most of the vagus nerve and provide parasympathetic innervation to the organs of the neck, thoracic and abdominal cavities. Impulses flow along the fibers of the vagus nerve, which slow down the rhythm of the heartbeat, dilate the vessels (reflexively regulate blood pressure in the vessels), narrow the bronchi, increase peristalsis and relax the intestinal sphincters, and 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, connected

Rice. 178. The relationship of the vagus nerves with the esophagus, aortic arch and its branches.

1-n. vagus dexter; 2, 11-n. vagus sinister; 3-a. carotis communis sinistra; 4-a. subclavia sinistra; 5 - arcus aortae; 6 - n. la-ryngealis recurrens sinister; 7-lig. arteriosum; 8 - truncus pulmonalis; 9 - bronchus principalis sinister; 10 - pars thoracica aortae; 12 - plexus oesophagealis; 13 - diaphragma; 14 - bronchus principalis dexter; 15-v. azygos; 16-v. cava superior; 17 - truncus brachiocephalicus; 18-a. subclavia dextra; 19 - trachea; 20-a. carotis communis dextra; 21-n. laryngealis recurrens dexter.

rising, they 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

a broken nerve and an upper knot. The following branches depart from this department:

1. Meningeal branch, r. 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. U w n I branch, r auricularis. starts from the bottom

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.

The cervical part of the vagus nerve includes 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:

pharyngeal branches, rr. pharyngei [ pharyngealis], 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.

superior cervical cardiac branches, rr. cardiaci cervicales superidres, in the amount of 1-3 they depart from the vagus nerve, descending along the common carotid artery, and together with the branches of the sympathetic trunk enter the cardiac plexus.

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 sublingual bone is divided into external and internal branches. Onhand branch,r. externus, innervates the cricothyroid muscle of the larynx. inner branch,r. 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.

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 upward 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. From the

portal laryngeal nerve also depart tracheal branches,rr. trachedles, esophageal branches,rr. esophagei [ oesophagealis] and inferior cervical cardiac branches,rr. cardiaci cervicles infe- priors, that go to the heart plexus. Also departs from the lower laryngeal nerve connecting branch(with internal laryngeal branch of the superior laryngeal nerve), r . 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:

thoracic branches, rr. cardiaci thoracici, are sent to the heart plexuses.

bronchial branches, rr. bronchiales, go to the root of the lung, where, together with the sympathetic nerves, they form pulmonaryplexus,plexus pulmondlis, which surrounds the bronchi and enters with them in lung.

esophageal plexus, plexus esophageus [ oeso phagealis] , formed by branches of the right and left vagus nerves (trunks) that connect 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.

Anterior wandering trunk, truncus vagalis 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 branchesrr. gastrici anteriores, as well as hepatic branches,r. hepdtici, running between the sheets of the lesser omentum to the liver.

Rear wandering trunk, truncus vagalis 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 1st celiac plexus along the left gastric artery. Fibers of the vagus nerves along with. sympathetic fibers of the celiac plexus go to the liver, spleen, pancreas, kidney, small intestine and large intestine to the descending colon.

Accessory nerve (XI)

Accessory nerve, p. accessorius , is a motor nerve that innervates the sternocleidomastoid and trapezius muscles. It has two cores. One nucleus lies within the medulla oblongata, and the other - in the spinal cord. The nerve begins with several cranial and spinal roots. skull roots, radices craniales, emerge from the posterior lateral groove of the medulla oblongata, spinal roots, radices spindles, from the same groove in the cervical part of the spinal cord and rise up. Educational

the collapsed trunk of the accessory nerve goes to the jugular foramen, where it is divided into two branches: internal and external. inner branch,r. internus, formed by fibers of both cranial and spinal roots, joins the trunk of the vagus nerve. outer branch,r. externus, exits the jugular foramen, goes first between the internal carotid artery and the internal jugular vein, and then, going under the posterior belly of the digastric muscle, goes to the sternocleidomastoid muscle. Having given it part of the branches, the external branch appears at the posterior edge of this muscle and then follows to the trapezius muscle, which it also innervates.

Hypoglossal nerve (XII)

Hypoglossal nerve, p. hypoglossus , - also motor, innervates the muscles of the tongue. Nerve fibers exit from the motor nucleus of the hypoglossal nerve, which is located in the medulla oblongata. The nerve emerges from the medulla oblongata in numerous roots in the groove between the pyramid and the olive. The trunk of the hypoglossal nerve goes forward and laterally into the canal of the same name and passes through it. After leaving the canal, the hypoglossal nerve goes down and anteriorly, bending around the vagus nerve and the internal carotid artery from the lateral side. After passing between the internal carotid artery and the internal jugular vein, the hypoglossal nerve goes under the posterior belly of the digastric muscle and under the stylohyoid muscle and leaves in submandibular triangle. Having formed an arc with its bulge downward, the hypoglossal nerve follows forward and up to the language, in the thickness of which it breaks up into lingual branches,rr. pp-guales, innervating muscles of the tongue.

A descending branch departs from the hypoglossal nerve, containing motor fibers that have joined from the first spinal nerve. This branch connects with the branches of the cervical plexus, as a result of which anterior to the common carotid artery is formed neck loop,ansa cervicalis (loop of the hypoglossal nerve).