nervous tissue. One part of them performs sensitive functions, the other – motor functions, the third combines both. They have afferent and efferent fibers (or only one of these types), responsible for receiving or transmitting information, respectively.

The first two nerves have significant differences from the rest from the 10, since they are essentially a continuation of the brain, formed through the protrusion of the brain vesicles. In addition, they do not have nodes (nuclei) that are present in the other 10. The nuclei of the cranial nerves, like other ganglia of the central nervous system, are concentrations of neurons that perform specific functions.

10 pairs, with the exception of the first two, are not formed from two types of roots (anterior and posterior), as happens with spinal roots, but represent only one root - anterior (in III, IV, VI, XI, XII) or posterior (in V, from VII to X).

The common term for this type of nerve is “cranial nerves,” although Russian-language sources prefer to use “cranial nerves.” This is not an error, but it is preferable to use the first term - in accordance with the international anatomical classification.

All cranial nerves are formed in the fetus already in the second month. At the 4th month of prenatal development, myelination of the vestibular nerve begins - the coating of fibers with myelin. Motor fibers go through this stage earlier than sensory fibers. The state of nerves in the postnatal period is characterized by the fact that, as a result, the first two pairs are the most developed, the rest continue to become more complex. Final myelination occurs around the age of one and a half years.

Classification

Before proceeding to a detailed examination of each individual pair (anatomy and functioning), it is most convenient to familiarize yourself with them using brief characteristics.

Table 1: Characteristics of 12 pairs

Numbering	Name	Functions
I	Olfactory	Sensitivity to odors
II	Visual	Transmission of visual stimuli to the brain
III	Oculomotor	Eye movements, pupillary response to light exposure
IV	Block	Moving the eyes downwards, outwards
V	Trigeminal	Facial, oral, pharyngeal sensitivity; activity of the muscles responsible for the act of chewing
VI	Abductor	Moving the eyes outward
VII	Facial	Movement of muscles (facial muscles, stapedius); activity of the salivary gland, sensitivity of the anterior part of the tongue
VIII	Auditory	Transmission of sound signals and impulses from inner ear
IX	Glossopharyngeal	Movement of the levator pharyngeal muscle; activity of paired salivary glands, sensitivity of the throat, middle ear cavity and auditory tube
X	Wandering	Motor processes in the muscles of the throat and some parts of the esophagus; providing sensitivity in the lower part of the throat, partially in the ear canal and eardrums, the dura mater of the brain; activity smooth muscles(gastrointestinal tract, lungs) and cardiac
XI	Additional	Abduction of the head in various directions, shrugging of the shoulders and adduction of the shoulder blades to the spine
XII	Sublingual	Movements and movements of the tongue, acts of swallowing and chewing

Nerves with sensory fibers

The olfactory begins in the nerve cells of the nasal mucous membranes, then passes through the cribriform plate into the cranial cavity to the olfactory bulb and rushes into the olfactory tract, which, in turn, forms a triangle. At the level of this triangle and tract, in the olfactory tubercle, the nerve ends.

Retinal ganglion cells give rise to the optic nerve. Having entered the cranial cavity, it forms a decussation and, as it passes further, it begins to bear the name “optic tract,” which ends in the lateral geniculate body. The central part originates from it visual pathway, going to the occipital lobe.

Auditory (also known as vestibulocochlear) consists of two. The cochlear root, formed from the cells of the spiral ganglion (belonging to the plate of the bony cochlea), is responsible for the transmission of auditory impulses. The vestibule, coming from the vestibular ganglion, carries impulses from the vestibular labyrinth. Both roots articulate into one in the internal auditory canal and are directed inward in the middle of the pons and medulla oblongata(the VII pair is located slightly lower). The fibers of the vestibule - a significant part of them - pass into the posterior longitudinal and vestibulospinal fascicles and the cerebellum. The fibers of the cochlea extend to the lower tubercles of the quadrigeminal and the medial geniculate body. The central one starts here auditory pathway, ending in the temporal gyrus.

There is another sensory nerve that has received the number zero. At first it was called “accessory olfactory”, but was later renamed terminal due to the presence of a terminal plate nearby. Scientists have yet to reliably establish the functions of this pair.

Motor

The oculomotor, starting in the nuclei of the midbrain (below the aqueduct), appears on the brain base in the region of the peduncle. Before heading into the orbit, it forms a branched system. Its upper section consists of two branches going to the muscles - the superior rectus and the one that raises the eyelid. The lower part is represented by three branches, two of which innervate the rectus muscles - the median and inferior muscles, respectively, and the third goes to the inferior oblique muscle.

The nuclei lying in front of the aqueduct at the same level as the lower tubercles of the quadruple create the beginning of the trochlear nerve, which appears on the surface in the roof area of ​​the fourth ventricle, forms a cross and stretches to the superior oblique muscle located in the orbit.

From the nuclei located in the tegmentum of the bridge, fibers pass that form the abducens nerve. It has an exit where the middle is located between the pyramid of the medulla oblongata and the bridge, after which it rushes into the orbit to the lateral rectus muscle.

The two components form the 11th accessory nerve. The upper one begins in the medulla oblongata - its cerebral nucleus, the lower one - in the spinal cord (its upper part), and more specifically, the accessory nucleus, which is localized in the anterior horns. The roots of the lower part, passing through the foramen magnum, are directed into the cranial cavity and connect with the upper part of the nerve, creating a single trunk. Coming out of the skull, it divides into two branches. The fibers of the upper one grow into the fibers of the 10th nerve, and the lower one goes to the sternocleidomastoid and trapezius muscles.

Core hypoglossal nerve is located in the rhomboid fossa (its lower zone), and the roots pass to the surface of the medulla oblongata in the middle of the olive and pyramid, after which they are combined into a single whole. The nerve emerges from the cranial cavity, then goes to the muscles of the tongue, where it produces 5 terminal branches.

Mixed fiber nerves

The anatomy of this group is complex due to its branched structure, which allows it to innervate many sections and organs.

Trigeminal

The area between the middle cerebellar peduncle and the pons is its exit point. The nucleus of the temporal bone forms the nerves: orbital, maxillary and mandibular. They have sensory fibers, and motor fibers are added to the latter. The orbital is located in the orbit (upper zone) and branches into the nasociliary, lacrimal and frontal. The maxillary has access to the surface of the face after it penetrates through the infraorbital space.

The mandibular bifurcates into an anterior (motor) and posterior (sensitive) part. They provide a nerve network:

• the anterior is divided into the masticatory, deep temporal, lateral pterygoid and buccal nerves;
• posterior - into the median pterygoid, auriculotemporal, inferior alveolar, mental and lingual, each of which is again divided into small branches(their number in total is 15 pieces).

The mandibular division of the trigeminal nerve communicates with the auricular, submandibular and sublingual nuclei.

The name of this nerve is known more than the other 11 pairs: Many people are familiar, at least by hearsay, about

24

28

Optic nerve (p. ophthalmicus) is the first branch of the trigeminal nerve (Fig. 2.6.1, 2.6.2, 2.7.1). In the area of ​​the cavernous sinus, the nerve is divided into 3 branches: frontal, nasociliary and lacrimal. These branches penetrate into the eye sockets

Rice. 2.7.1. Nerves of the orbit (view from above):

1 - abducens nerve; 2 - trochlear nerve; 3 - oculomotor nerve; 4 - internal carotid artery and nerve plexus; 5 - optic nerve; 6 - optic nerve; 7 - common tendon ring; 8 - trochlear nerve; 9 - nasociliary nerve; 10 - subtrochlear nerve; // - superior oblique muscle; 12 - internal rectus muscle; 13 - supratrochlear nerve; 14 - supraorbital nerve; /5 - levator of the upper eyelid; 16 - superior rectus muscle; 17 - lacrimal gland; 18 - lacrimal nerve; 19 - external rectus muscle; 20 - frontal nerve; 21 - maxillary nerve; 22 - meningeal (meningeal) branch of the maxillary nerve; 23 - mandibular nerve; 24 - lesser petrosal nerve;

25 - meningeal (meningeal) branch of the mandibular nerve;

26 - greater petrosal nerve; 27 - trigeminal (lunar)
ganglion; 28 - meningeal branch of the optic nerve

Chapter 2. ORBITS AND AUXILIARY APPARATUS OF THE EYE

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15

16

tsu separately through the top orbital fissure. In the cavernous sinus, the ophthalmic nerve gives off branches to the oculomotor nerve (p. oculomoto-rius), bloc (p. trochlearls) and the outlet (p. abducens). The optic nerve is joined in the cavernous sinus by sympathetic branches emanating from the carotid plexus.

Lacrimal nerve (n. lacrimalis) enters the orbit through the superior orbital fissure immediately above the ring of zinc. Uniting with the lacrimal artery, the lacrimal nerve is directed anteriorly, located above and temporally from the external rectus muscle of the eye, and then penetrates the lacrimal gland from its posterior surface. Here it forms the upper and lower branches. The first innervates the lacrimal gland, conjunctiva and the outer part of the upper eyelid. Before entering the gland, the lacrimal nerve receives a branch from the zygomaticotemporal nerve (p. zygomaticotemporalis), containing parasympathetic fibers.

Frontal nerve (p. frontalis) penetrates the orbit through the superior orbital fissure above the ring of zinn and is directed anteriorly along the periosteum of the upper wall of the orbit. Not far from the anterior edge of the orbit, it divides into the supratrochlear and supraorbital nerves (Fig. 2.7.1). The supraorbital nerve continues forward and leaves the orbit along with the supraorbital artery through the foramen of the same name.

The frontal nerve provides sensory innervation upper eyelid, forehead skin, scalp and frontal sinus.

The supratrochlear nerve also runs anteriorly and leaves the orbit through the supratrochlear notch, located slightly above the supraorbital nerve. The frontal nerve innervates the skin of the forehead, conjunctiva and upper eyelid.

Nasociliary nerve (n. nasociliaris) penetrates into the orbit through the superior orbital fissure, located in the ring of Zinn (Fig. 2.7.2). Only this branch of the trigeminal nerve provides sensitive innervation to the eyeball.

Immediately after entering the orbit, the nasociliary nerve lies above the optic nerve along with the ophthalmic artery. Moreover, it is located between the superior oblique and internal rectus muscles. Subsequently, the nerve runs along the ophthalmic artery from its inner side.

Several branches are separated from the nasociliary nerve. The first branch is the sensory root of the ciliary ganglion (ganglion ciliare), which lies one centimeter anterior to the optic canal. In the place where the nasociliary nerve is located with inside optic nerve, its branches form long ciliary nerves (pp. ciliares longi). There are usually two of them. Long ciliary (ciliary) nerves pierce the sclera and are directed anteriorly in the subchoroidal space, innervating the iris, ciliary

Rice. 2.7.2. Nerves of the orbit (view from above; levator upper eyelid, superior rectus and superior oblique muscles partially removed):

/ - abducens nerve; 2 - oculomotor nerve; 3 - trochlear nerve (cut); 4- internal carotid plexus; 5- nasociliary nerve; 6 - superior branch of the oculomotor nerve (cut); 7- posterior ethmoidal nerve; 8 - optic nerve; 9 - anterior ethmoidal nerve; 10 - subtrochlear nerve; //-branches of the superior orbital nerve (cut); 12 - supratrochlear nerve; 13 - long ciliary nerves; 14 - short ciliary nerves; 15 - lacrimal nerve; 16 - ciliary ganglion; 17 - parasympathetic root from the oculomotor nerve; 18 - sympathetic root of the internal carotid plexus; 19 - sensitive root coming from the nasociliary nerve; 20 - branches to the inferior and internal rectus muscles; 21 - abducens nerve; 22 - inferior branch of the oculomotor nerve; 23 - lacrimal nerve; 24 - frontal nerve; 25 - optic nerve

body and cornea. They also carry sympathetic fibers to the dilator iris.

Branches of the posterior ethmoidal nerve (p. ethmo-idalis posterior) separated from the nasociliary nerve (p. nasocilliaris), pass medially and enter the posterior ethmoidal foramina (foramen ethmoidalis posterior)(Fig. 2.7.2). The two terminal branches of the nasociliary nerve are none other than the anterior ethmoidal nerve (n. ethmoidalis anterior) and subtrochlear nerve (n. infratrochlearis).

The anterior ethmoidal nerve enters through the anterior ethmoidal foramina and innervates the anterior part of the ethmoid bone. It then penetrates the anterior cranial fossa and then, as the external nasal nerve, travels down through the roof of the nose, innervating a small area of ​​the nose.

The subtrochlear nerve goes forward, leaves the orbit and innervates the internal

Nerves of the orbit

Part of the conjunctiva, skin, lacrimal sac and lacrimal canaliculi.

Ciliary ganglion (Ganglion ciliary). This ganglion belongs to the autonomic nervous system (Fig. 2.7.3, see color on; 2.7.4). It is here that the parasympathetic fibers are interrupted, coming from the Yakubovich-Edinger-Westfall nucleus as part of the oculomotor nerve to the smooth muscles of the eye.

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Rice. 2.7.4. Ciliary ganglion and distribution of branches of the oculomotor nerve:

/ - oculomotor nerve; 2 - superior branch of the oculomotor nerve; 3 -branch to the levator of the upper eyelid; 4 -branch to the superior rectus muscle; 5 - short ciliary nerves; b - nerve going to the sphincter and dilator; 7 - branch to the internal rectus muscle; 8 - branch to the inferior rectus muscle; 9 - branch to the inferior oblique muscle; 10 - sympathetic root; // - sensitive root; 12 - ciliary ganglion; 13 - motor root

The ciliary ganglion varies in shape and size. Its length is about 1.5 mm. It is located outside the optic nerve approximately 1 ur from the optic opening and 1.5 cm behind the eyeball. This place is located just between the external rectus muscle of the eye and the optic nerve.

The ciliary ganglion has three dorsal roots: a sensory root coming from the nasociliary nerve, a motor root from the branches of the oculomotor nerve, and a sympathetic root from the sympathetic plexus.

The motor root innervates the inferior oblique muscle and, as stated above, carries parasympathetic fibers. These paraganglionic fibers are the only fibers that are interrupted in the ganglion. Other fibers (sensory and sympathetic) pass through it without interruption. All motor cell nuclei in the ciliary ganglion thus give rise to postganglionic parasympathetic fibers.

Warwick found that 3% of postganglionic parasympathetic fibers are directed to the iris, and 94% to the ciliary body. Thus, the majority of parasympathetic fibers control accommodation and only 3% provide pupil constriction.

The sensitive root of the nasociliary nerve sends afferent fibers to the cornea and iris, as well as to the ciliary body.

The sympathetic root comes from the plexus located around the internal carotid artery and sends sympathetic fibers towards the vessels of the eye.

The sensory root coming from the nasociliary nerve is sometimes a real anatomical formation.

Sympathetic innervation can be provided either by a branch of the nerve trunk emanating from the nasociliary nerve or from the sympathetic plexus of the ophthalmic artery.

From the anterior end of the ciliary ganglion, 3-6 branches of short ciliary nerves originate, piercing the sclera around the optic nerve. Along the course of these nerves in eyeball parasympathetic fibers penetrate to the muscles that dilate and constrict the pupil (dilator and sphincter of the iris) (Fig. 2.7.3, see color on).

Maxillary nerve (n. maxillaris) is the second branch of the trigeminal nerve. Two branches of this nerve enter the orbit through the infraorbital fissure. The final branch The maxillary nerve is the infraorbital nerve. It lies in the infraorbital groove, goes into the infraorbital canal and leaves the orbit.

The infraorbital nerve provides sensory fibers to the skin of the cheek and the surface of the nose.

Second branch maxillary nerve is the zygomatic nerve (n. zygomaticus). After entering the orbit, it divides into the zygomaticofacial nerve, which lies on the lateral orbital wall, and the zygomaticotemporal nerve, which runs upward along the orbital wall. Here the zygomaticotemporal nerve connects with the lacrimal nerve and supplies parasympathetic fibers to the lacrimal gland.

N. centripetal) N. formed by sensory nerve fibers and conducting nervous excitement from receptors to nerve centers.

Large medical dictionary. 2000 .

See what a “sensory nerve” is in other dictionaries:

The nerve along which to the central nervous system afferent information arrives from peripheral parts of the body. Various sensory nerves transmit information to the brain about temperature, pain, touch, food taste, etc. For comparison:... ... Medical terms

SENSITIVE NERVE, SENSORY NERVE- (sensory nerve) a nerve through which afferent information from peripheral parts of the body enters the central nervous system. Various sensory nerves transmit information to the brain about temperature, pain, touch, taste of food, etc.... ... Explanatory dictionary of medicine

SENSITIVE, sensitive, sensitive; sensitive, sensitive, sensitive. 1. Capable of vividly feeling, perceiving, having developed feelings, impressionable. “He was kind and sensitive, but cold and somewhat arrogant... Ushakov's Explanatory Dictionary

The nerve through which impulses arrive from the central nervous system, ensuring the active activity of the muscles and glands located in the human body. For comparison: The nerve is sensitive. Source: Medical Dictionary... Medical terms

MOTOR NERVE- (motor nerve) a nerve through which impulses arrive from the central nervous system, ensuring the active activity of the muscles and glands located in the human body. For comparison: The nerve is sensitive... Explanatory dictionary of medicine

- (n. afferens) see Sensory nerve... Large medical dictionary

- (n. centripetalis) see Sensory nerve... Large medical dictionary

The eighth cranial sensory nerve (VIII), which carries impulses from the vestibular apparatus and the organ of Corti of the inner ear from the inner ear to the brain. This nerve has two parts: the vestibular nerve and... Medical terms

VESTICOCHELLAR NERVE, AUDITORY NERVE- (auditory nerve) the eighth cranial sensory nerve (VIII), through which impulses from the vestibular apparatus and the organ of Corti of the inner ear arrive from the inner ear to the brain. This nerve has two parts: the nerve of the vestibule... ... Explanatory dictionary of medicine

The fifth (largest) mixed cranial nerve (V), which along its course is divided into three branches: the ophthalmic (sensitive), maxillary (sensitive) and mandibular (mixed) nerves. Motor fibers innervate... ... Medical terms

Cranial nerves(cranial nerves, lat. nervi craniales) - twelve pairs of nerves extending from. They are designated by Roman numerals in the order in which they are located, each of them has its own name.

In Russian-language sources, the term cranial nerves is often used. According to the latest anatomical terminology adopted in Sao Paulo in 1997, the term is designated as lat. Nervi craniales(cranial nerves). In the 6th edition of Sinelnikov’s atlas of human anatomy, monographs dedicated to human anatomy, the term is unified under the international anatomical classification. At the same time, the frequency of use of the combination “cranial nerves” is evidenced by the first phrase of the corresponding article in the Great Soviet Encyclopedia:

Cranial nerves, more correctly cranial

List of nerves

• I pair - (lat. nervus olfactorius)
• II pair - optic nerve (lat. nervus opticus)
• III pair - oculomotor nerve (lat. nervus oculomotorius)
• IV pair - trochlear nerve (lat. nervus trochlearis)
• V pair - trigeminal nerve (lat. nervus trigeminus)
• VI pair - abducens nerve (lat. nervus abducens)
• VII pair - facial nerve (lat. nervus facialis)
• VIII pair - vestibulocochlear nerve (lat. nervus vestibulocochlearis)
• IX pair - glossopharyngeal nerve (lat. nervus glossopharyngeus)
• X pair - vagus nerve (lat. nervus vagus)
• XI pair - accessory nerve (lat. nervus accessorius)
• XII pair - hypoglossal nerve (lat. nervus hypoglossus)

Mnemonic rules

Onegin Knew Where Tatyana Was, He Loved to Listen to the Language of his Infinitely Dear Friend.

Onegin Knew Where Tatyana Was, He Was Flying Like a Bullet, His Tongue Lolling Out to His Waist.

To remember a pair of cranial nerves on Latin: About Oryasina, the Donkey sharpens the axe, and the Fakir, having kicked out the Guests, wants to howl like a Shark.

Smell, look, move your eyes, remove the trigeminal block, face, tongue and throat. Don't fornicate in vain. Add under tongues.

I smelled, I saw, I moved my eye, and the trigeminal block abducted. Face and hearing, and glossopharynx, wandering, walked with an additional gait, finding all the nerves under the tongue.

Development of cranial nerves in embryogenesis

Olfactory and optic nerves develop from protrusions of the anterior medullary bladder and consist of axons of neurons that are located in the mucous membrane of the nasal cavity (organ) or in the retina of the eye. The remaining sensory nerves are formed by the eviction of young nerve cells from the developing brain, the processes of which form sensory nerves or sensory (afferent) fibers of mixed nerves. Motor cranial nerves are formed from motor (efferent) nerve fibers, which are processes of cells of the motor nuclei located in the brain stem. The formation of cranial nerves in phylogenesis is associated with the development of visceral arches and their derivatives, and the reduction of somites in the head region.

Where cranial nerves exit the brain

It is impossible to say about the first (olfactory) nerve that it “comes out” of the brain, since it carries only afferent (sensitive) information. The olfactory nerve is the processes of the olfactory cells of the nasal mucosa, collected in olfactory filaments. The olfactory filaments reach the olfactory bulb through the openings of the cribriform plate of the ethmoid bone.

It is also impossible to say about the second (optic) nerve that it “comes out” of the brain, for the same reason. It originates from the optic nerve head, located at the posterior pole of the eye. The optic nerve passes into the cranial cavity through the optic canal formed by the lesser wing of the sphenoid bone. In the cranial cavity, the optic nerves of both eyes form a chiasm, and only part of the fibers intersect. Further, the fiber paths are called the “optic tract”.

The third (oculomotor) nerve exits from the ventral (“facial”) side of the trunk next to the interpeduncular fossa (fossa interpeduncularis).

The IV (trochlear) nerve is the only one emerging from the dorsal (“dorsal”) side of the trunk, from the upper edge, bending, exiting to the ventral side from under the cerebral peduncles.

The V (trigeminal) nerve exits the ventral side of the pons.

Nerves VI through VIII also exit on the ventral side of the brain stem between and the pons, from the edges to the center in a row, with VII and VIII lying close to each other at the “angle” of the medulla oblongata, and VI (abducens) at the level of the anterolateral sulcus.

Nerves IX to XII emerge from the medulla oblongata on the ventral side. The XI (accessory) nerve stands somewhat apart - it combines, in addition to the head part, some roots. Nerves IX to XI emerge from the lateral surface of the medulla, from bottom to top in a row.

The XII (hypoglossal) nerve emerges from the anterolateral groove (lat. sulcus ventrolateralis).

Cranial nerve nuclei

core	nerve	kernel type	what innervates	which provides
The magnocellular nucleus of the oculomotor nerve (paired)	III pair	motor	muscle levator superior eyelid, upper, lower and medial muscle eyes, inferior oblique muscle of the eye	eye movement, raising the upper eyelid
Small cell nucleus of the oculomotor nerve (syn. Yakubovich nucleus), paired	III pair	parasympathetic	muscle constrictor pupil (lat. m.sphincter pupillae)	constriction of the pupil
Small cell unpaired nucleus of the oculomotor nerve (syn. nucleus of Perlia)	III pair	parasympathetic	ciliary muscle (lat. m.ciliaris)	lens accommodation
Trochlear nerve nucleus	IV pair	motor	superior oblique muscle (lat. m.obliquus superior)	moving the eye outward and downward
The nucleus of the spinal tract of the trigeminal nerve (lat. nucleus tractus spinalis n.trigemini)	V pair	sensitive	face	superficial (pain and tactile) sensitivity
Nucleus of deep sensitivity of the trigeminal nerve (lat. nucleus sensorius principalis n.trigemini)	V pair	sensitive	face	deep () sensitivity
Motor nucleus of the trigeminal nerve (lat. nucleus motorius (masticatorius) n.trigemini)	V pair	motor	masticatory muscles (masseter, temporalis, lateral and medial pterygoid, mylohyoid muscles, anterior belly of the digastric muscle and muscle that tightens the soft palate)	chewing
The nucleus of the abducens nerve (lat. nucleus abducentis)	VI pair	motor	lateral rectus muscle (lat. m.rectus lateralis)	abduction of the eyeball outwards
The nucleus of the facial nerve (lat. nucleus n.facialis)	VII pair	motor	facial muscles	facial expressions
Nucleus of the solitary tract (lat. nucleus tractus solitarii)	VII and IX pairs	sensitive	language ( )	taste
Superior salivary nucleus (lat. nucleus salivatorius superior)	VII pair	parasympathetic	lacrimal gland, submandibular and sublingual salivary glands	tearing, salivation
Anterior and posterior cochlear nuclei (lat. nuclei cochleares anterior et posterior)	VIII pair	sensitive	(auditory receptors)	hearing
Vestibular nuclei (superior, lateral, medial and inferior) (lat. nuclei vestibulares)	VIII pair	sensitive	inner ear (vestibular receptors)	vestibular apparatus
Double core (lat. nucleus ambiguus)	IX, X and XI pairs	motor	muscles of the soft palate, pharynx and larynx	chewing, voice,
Inferior salivary nucleus (lat. nucleus salivatorius inferior)	IX pair	parasympathetic	parotid gland	salivation
Sensitive nucleus of the glossopharyngeal and vagus nerves (lat. nucleus alae cinereae)	IX and X pairs	sensitive	oral cavity, middle and inner ear	overall sensitivity of these areas
Posterior core vagus nerve(lat. nucleus dorsalis n.vagi)	X pair	parasympathetic	heart muscle, smooth muscles of the lungs, bronchi, stomach and intestines	heart rate, secretion of endocrine glands of the gastrointestinal tract, bronchial smooth muscle tone
The nucleus of the accessory nerve (lat. nucleus n.accessorii)	XI pair	motor	trapezoid and sternocleidomastoid (lat. m.sternocleidomastoideus)	turning the head, lifting the shoulder, scapula and acromial part of the clavicle upward (“shrug”), pulling the shoulder girdle back and bringing the scapula to the spine
Hypoglossal nerve nucleus (lat. nucleus n.hypoglossi)	XII pair	motor	muscles of the tongue and orbicularis oris	tongue movement, swallowing, sucking, licking, etc.

Functions of cranial nerves

Olfactory nerve (olfactory nerves) (lat. nervi olfactorii) is the first of the cranial nerves responsible for olfactory sensitivity.

Optic nerve(lat. Nervus opticus) - the second pair of cranial nerves through which visual stimuli perceived by the sensitive cells of the retina are transmitted to the brain.

Oculomotor nerve(lat. nervus oculomotorius) - III pair of cranial nerves, responsible for the movement of the eyeball, raising the eyelid, and the reaction of the pupils to light.

Trochlear nerve lat. nervus trochlearis- IV pair of cranial nerves, which innervates the superior oblique muscle (lat. m.obliquus superior), which turns the eyeball outward and downward.

V (trigeminal) nerve is mixed. Its three branches (ramus ophthalmicus - V1, ramus maxillaris - V2, ramus mandibularis - V3) through the Gasserian ganglion (ganglion trigeminale) carry information from the upper, middle and lower thirds of the face, respectively. Each branch carries information from the muscles, skin and pain receptors of each third of the face. In the Gaserian ganglion, information is sorted by type, and information from the muscles of the entire face goes to the sensitive nucleus of the trigeminal nerve, located mostly in (partially enters the pons); cutaneous information from the entire face goes to the “main nucleus” (nucleus pontinus nervi trigemini), located in the pons; and pain sensitivity is in the nucleus spinalis nervi trigemini, coming from the bridge through the medulla oblongata to the spinal cord.

The trigeminal nerve also belongs to the motor nucleus (lat. nucleus motorius nervi trigemini), located in the bridge and responsible for the innervation of the masticatory muscles.

Abducens nerve(lat. nervus abducens) - VI pair of cranial nerves, which innervates the lateral rectus muscle (lat. m. rectus lateralis) is responsible for abduction of the eyeball.

Facial nerve(lat. nervus facialis), the seventh (VII) of the twelve cranial nerves, exits the brain between the pons and the medulla oblongata. The facial nerve innervates the facial muscles. Also included in the facial nerve is the intermediate nerve, which is responsible for the innervation of the lacrimal gland, the stapedius muscle and the taste sensitivity of the two anterior third tongues.

vestibulocochlear nerve(lat. nervus vestibulocochlearis) - a nerve of special sensitivity responsible for the transmission of auditory impulses and impulses emanating from the vestibular part of the inner ear.

Glossopharyngeal nerve(lat. nervus glossopharyngeus) - IX pair of cranial nerves. Is mixed. Provides:

• motor innervation of the stylopharyngeal muscle (lat. m. stylohyoideus), elevating the pharynx
• innervation of the parotid gland (lat. glandula parotis) providing its secretory function
• general sensitivity of the pharynx, tonsils, soft palate, Eustachian tube, tympanic cavity
• taste sensitivity of the posterior third of the tongue.

Nervus vagus(lat. n.vagus) - X pair of cranial nerves. Is mixed. Provides:

• motor innervation of the muscles of the soft palate, pharynx, larynx, as well as striated muscles of the esophagus
• parasympathetic innervation of smooth muscles of the lungs, esophagus, stomach and intestines (up to the splenic flexure colon), as well as the muscles of the heart. Also affects the secretion of the glands of the stomach and pancreas
• sensitive innervation of the mucous membrane of the lower part of the pharynx and larynx, the skin behind the ear and part of the external auditory canal, the eardrum and the dura mater of the posterior cranial fossa.

Accessory nerve(lat. nervus accessorius) - XI pair of cranial nerves. Contains motor nerve fibers that innervate the muscles responsible for turning the head, raising the shoulder and adducting the scapula to the spine.

Hypoglossal nerve(lat. nervus hypoglossus) - XII pair of cranial nerves. Responsible for the movement of the tongue.

The nervous system (NS) ensures the vital functions of the body due to its ability to respond to external and internal stimuli. The NS is divided into central and peripheral. Departments of the National Assembly differ in the functions they perform. The functions of the somatic nervous system can be controlled by consciousness, meanwhile, the functions of the autonomic nervous system are not controlled by our consciousness - it regulates vital processes in the body. Nerves consist of nerve fibers parallel to each other. According to their functions, the fibers of the nervous system are divided into motor, sensory and autonomic nerves.

Motor nerves transmit excitation from the central nervous system to the striated muscles. Thanks to them, we can tense our muscles, breathe, etc.

Along sensory nerves, impulses travel from peripheral receptors to the central nervous system. Thanks to sensitive fibers, we feel pain, cold and heat, determine the mass and shape of objects.

They form the autonomic or autonomic nervous system, which coordinates the activity of smooth muscles, various glands and the heart. The autonomic nervous system is divided into two sections: sympathetic and parasympathetic, which regulate activity differently internal organs. For example, with increased functioning of the parasympathetic nervous system, diarrhea appears. If the sympathetic nervous system dominates, then reverse processes occur.

Basic motor and sensory nerve fibers

The peripheral nervous system includes the cranial and spinal nerves, as well as the nerves of the autonomic nervous system.

Cranial nerves

Humans have 12 pairs of cranial nerves. They consist of motor or sensory fibers, or can be mixed, i.e. consist of both. Cranial nerves arise from the brain stem or medulla oblongata and innervate the tissues of the head and neck. Let's name them all:

• Olfactory (from Latin n. olfactorius).
• Visual (n. opticus).
• Oculomotor (n. oculomotorius).
• Block (n. trochlearis).
• Trigeminal (n. trigeminus).
• Facial (n. facialis).
• vestibulocochlearis (n. vestibulocochlearis).
• Abductor (n. abducens).
• Glossopharyngeus (n. glossopharyngeus).
• Vagus (n. vagus).
• Accessory (n. accesorius).
• Sublingual (n. hypoglossus).

Spinal nerves

From spinal cord 31 pairs of spinal nerves arise:

• Cervical (8 pairs) - roots extend from the cervical part of the spinal cord.
• Thoracic (12 pairs) - from the thoracic part of the spinal cord.
• Lumbar (5 pairs) - from the lumbar part of the spinal cord.
• Sacral (5 pairs) - from the sacral part.
• Coccygeal (1 pair) - from the end part.

The spinal nerves innervate the muscles of the trunk, as well as the muscles of the lower and upper extremities.