How many pairs of nerves move away from the spinal cord? their anatomy

Pair of spinal cord nerves: functions

Answering the question about how many pairs of nerves move away from the spinal cord, 8 cervical, 12 thoracic, 5 in the lumbar region, 5 sacral and one outgoing from the coccyx.

Depending on which of the nerve fibers is irritated, the reaction of muscles, skin or vessels and glands is manifested.

These paired barrels are metamerically located. Each carries out the innervation of a specific part of the body.

From their functionality depends the work of all organs, vessels and glands, as well as the sensitivity of the skin and motor activity, which is normal in a person.

Features of the structure

A detailed description of 31 pairs of spinal nerves contains a table in which:

• the name of the plexus;
• Segment number involved in the plexus;
• the name of the nerves that make up the plexus;
• site of innervation.

The pairs of nerves of the spinal cord begin with the anterior and posterior roots. All of them contain sensitive and motor threads. Afferent (or bringing) belong to the posterior root, and efferent (relative) to the anterior.

The processes of the cells that are in the lateral horns and come out in the number of the front roots are nothing more than sympathetic threads. They contain:

1. in the two upper lumbar;
2. in the eighth cervine;
3. in each thoracic.

As for parasympathetic threads, they are part of the second, third and fourth sacral vertebrae.

At the exit from the hole between them, the nerve column formed by the fusion of the roots is divided into three branches (anterior, posterior and meningeal), while sympathetic forms also a white branch, which refers to connective.

From the spinal cord leaves 31 pairs of nerves, each of which is divided into components.

Specifically, the posterior part is divided into medial and lateral. They are responsible for the connection with the CNS of deep back muscles, the skin of the occipital region of the head. Segmental distribution of the foreground is preserved only in the chest region. Here they are called intercostal.

As for the other divisions, in them the anterior branches are connected in the form of loops and form plexuses:

• cervical,
• shoulder,
• lumbar,
• sacral.

The cervical plexus includes fibers of cutaneous and muscular, as well as diaphragmatic. The humerus is divided into the supraclavicular and subclavian parts, the musculocutaneous, ulnar, radial, median and axillary nerve. The lumbar plexus includes:

1. short and long;
2. lateral cutaneous;
3. femoral and obturator.

The sacral weave in the small pelvis forms strong large loops, from which the short and long threads belogo, related to the weave in the waist and sacrum, they carry innervation of the external genitalia, small pelvis, hands and feet.

Sacrum is formed, starting with the 5th lumbar for the 4th sacrum. They are controlled by the gluteus muscular tissues, and the largest branch is sciatic.

If it is difficult to remember and understand exactly how the spinal nerves function, you can record the data that are given in the table. For the supply of signals from the peripheral nervous system to the membranes of the spinal cord, the meningeal branches respond.

To each of the existing brain vasodilators, gray connecting branches that are guarantors of a full-fledged communication existing between the central nervous system, blood vessels and glands, organs and tissues of the whole organism.

Plexus of nerves

So, the number of pairs of spinal nerves in a person is 31. They provide communication with certain areas and zones of the human body.

Studying their distinctive features and characteristics, one should know that functional nuances depend on the place of their exit.

For example, if the front roots are damaged, mobility is impaired, and in the case of a trauma to the back, the sensitivity is reduced or lost.

Thinking about how many pairs of spinal nerves you know, you need to remember the existence of the spine. Neck - 8 vertebrae and as many double white veins, in the lower back and sacrum - five, coccyx - only 1.

A special place is occupied by 12 pairs of spinal nerves in the thoracic region. Their main function is to ensure a permanent connection with the central nervous system of the skin of the thorax of the muscles of the abdominal wall. The main difference is the absence of interlacing.

Speaking about how many pairs of spinal nerves there are, it is necessary to remember all vertebrae, of which the spine consists.

Through them, control is exercised over the trunk, arms and legs, glands of internal secretion, organs, vessels and even metabolism.

So, for example, the weave in the loin, formed by vasodilators and vasoconstrictors 1 to 4, is in the depth of the muscle tissue. They are located on the anterior and lateral surfaces of the vertebrae of this department.

Branches guarantee innervation of the external, anterior and inner surface of the thigh, control its mobility and sensitivity.

8 pairs of nerves of the cervical region, five lumbar and sacral, and one coccygeal form complex plexuses, especially connected to each other. In several joints, the vasodilator trunks seem to be exchanging fibers.

The plexus becomes the guarantor of that each group of threads will be provided with a set of fibers intended for innervation of certain organs and tissues, skin and vessels.

Denial of responsibility

The information in the articles is intended only for general reading and should not be used for self-diagnosis of health problems or for therapeutic purposes.

This article is not a substitute for medical advice from a doctor (neurologist, therapist).

Please consult your doctor first to know the exact cause of your health problem.

A source: http://osteohondrosy.net/pary-nervov-spinnogo-mozga-funkcii.html

Spinal nerves in the human body - the structure, functions and formation

The spinal cord consists of numerous plexuses that form the spinal nerves, which represent paired trunks.

Each pair corresponds to a certain part of the body, internal organs, performs its unique functions. A total of 31 pairs, which corresponds to the number of pairs of segments of the spinal cord.

It is important to understand what the human plexus is, what they are needed for, what functions will be performed in the body during their work.

What is spinal nerves?

In the spinal canal is the spinal cord, which represents the initial structure of the central nervous system. This important part of the body, flattened from the front, has a cylindrical shape.

Structurally it has front branches and back roots, which serve to transmit impulses to the cortex of the brain. The answer to the question of how many spinal nerves deviates from the spinal cord is simple-31 pairs.

This amount is the same for women, men, does not depend on the age of the patients.

The spinal nerve consists of a large number of cells - neurons, which provide the reflex, sympathetic and motor functions of the body.

Individual nerves are woven into bundles, which have an official name, move along afferent paths (ascending) and descending paths. Formed spinal plexus is found in three types: lumbosacral, brachial, cervical.

The nerves of the region of the spinal cord are short structures, since their length is, cm. Further, they branch out from all sides, forming the posterior and anterior shell branches.

Structurally, the posterior branches of the spinal nerves stretch between the transverse processes of the pair of the back region, promoting flexion and extension of the trunk. The median slit is located on the front surface.

Such constructive elements conditionally divide the brain into the right, left half, closely related to each other in functionality.

In each component, lateral furrows are distinguished in front and back. The first is a site with the exit of the posterior sensory roots of the spinal nerves, and the second provides a branch of the motor nerves.

The lateral sulci are considered conditional boundaries between the posterior, lateral, anterior cords. In the cavity of the spinal cord, the central canal is located - a gap filled with a special substance called the cerebrospinal fluid.

Number of spinal nerves

An adult has 31 pairs of spinal nerves, and such elements are characterized by their conditional classification.

This division is represented by 8 cervical, 5 lumbar, 12 thoracic, 5 sacral, 1 coccygeal plexus. The total number of nerves is 62 positions, they enter into the majority of internal organs, systems (parts of the body).

Without their presence, muscular activity is excluded, normal brain activity is also pathologically reduced.

Departments

Studying the constructive parts of the human spine, it is necessary to identify those important structures that are permeated with nerves by fibers, contain the spinal cord.

They are responsible for locomotor activity, sensitivity to provoking factors from outside.

These are the following parts of the spinal column:

1. If you study the neck area, the cervical plexus is formed by the anterior branches, localized between the deep muscular structures. The supply of nerve cells is observed in the nape of the neck, the ear canal, the clavicle, the muscle tissue of the neck, and the medulla. In this way, nerve impulses are transmitted to ensure mobility of the upper limbs. In the case of pathology, the first is the occipital region.
2. The cerebrospinal structures of the sacral and lumbar region are responsible for the mobility of the lower extremities, the formation and maintenance of muscle tone. At the same time, the pelvic area, all internal organs, is monitored. Especially sensitive ischium, coccygeal and femoral nerves, pinching of which leads to acute pain syndrome. If such unpleasant sensations are present, it means that the pathological process takes place in the body.
3. Nerves of the chest are present in an amount of 12 pairs, located in the intercostal space. The main task is to provide mobility of the thorax, the muscles of the thin walls of the peritoneum. In this area, spinal plexus is not formed, go directly to the muscles. The pathologies of the characteristic site are accompanied by painfulness, but with timely selected treatment, the pain syndrome will descend.

Internal content

The spinal roots have the main center - the spinal cord, whose shells are filled with liquor. It contains a gray and white substance.

Each structure performs its unique functions. For example, a white substance consists of neurons that form three pillars - a side, front and back.

Each element in the section takes the form of horns and performs its task.

Thus, the anterior horns contain motor nerves, the posterior horns consist of sensitive fibers, and the lateral ones have a direct connection with the gray matter of the spinal cord.

The gray matter is surrounded by white, forming the cords of the spinal cord from longitudinally located nerve fibers.

Functions

The main tasks of the nerves of the spinal cord are the conductor and reflex.

In the first case we are talking about the passage of nerve impulses to the cerebral cortex in order to further ensure a natural reaction to external and internal irritating factors, for example, pain, temperature, cold, irritation.

The reflex function performed by the nerve centers ensures the innervation of skeletal muscles, provides the work of all internal organs and systems. Given this classification, the nerves of the spinal cord are:

• sensitive - ensure the reaction of the body (skin) to the effect of external and internal stimuli, mainly through the skin;
• motor - take and control physical activity of muscles, maintain balance, ensure coordination of movements, tone of smooth muscles;
• mixed - this spinal plexus, formed from motor and sensitive fibers. The functions of such nodes are numerous, but depend on the localization of nerve endings.

Nerve fibers differ not only in their functionality, but also in the area of ​​action in the human body (innervation).

Such solid structures are located and spread throughout the body, and the inflammation of the nodes leads to irreversible effects on the body.

Habitual motor activity and sensitivity are not returned immediately, it is required to undergo conservative treatment.

How nerves are formed

Nerve endings have a standard structure, and their differences are explained by the functional features of the roots. Structurally distinguish the front branches and back roots.

In the first case we are talking about motor neurons formed by axons, which are responsible for the mobility of the limbs.

As for the posterior roots, it is the formation of the spinal nerve and its branches, which are connected in series with the posterior horns and sensitive nuclei of the spinal cord. Such anatomical structures quickly transmit nerve impulses.

A source: http://sovets.net/12003-spinnomozgovye-nervy.html

Structure of the spinal cord

The spinal cord in appearance is a long, cylindrical shape, flattened from front to back of the neck with a narrow cavity - the central canal.

The spinal cord is located in the spinal canal, formed by the lateral processes of the vertebrae. As a continuation of the brainstem, the spinal cord has its own specific structure.

It has the form of a white cord about the thickness, cm. In the cervical and lumbar regions there are thickenings associated with innervation of the upper and lower extremities.

The length of the spinal cord depends on the growth of a person and is 40-45 cm.

The front and back surfaces of the spinal cord have longitudinal grooves.

On the ventral surface of the spinal cord lies a deep anterior median gap, into which penetrates the densely enclosing spinal cord, the soft medulla.

On the dorsal surface there is a very narrow posterior central groove. These two furrows divide the spinal cord into the right and left halves.

The spinal cord is characterized by a segmental structure. Each segment, or segment, gives rise to one pair of nerves. Total segments 31. From each segment a pair of motor (front) and a pair of sensitive (posterior) nerve roots leave.

Thus, 8 pairs leave the cervical region, 12 from the thoracic, 12 from the lumbar, 5 from the sacral and 5 from the sacral spine, and 1 pair of spinal roots.

The motor and sensory roots on the way out of the spinal cord are connected together and sent to the intervertebral openings, where the sensory spine forms the spinal ganglion (node).

Formed from the junction of the anterior and posterior roots, the spinal stems, after leaving the intervertebral foramen, form plexus - cervical, humeral, lumbosacral, from which the peripheral nerves, innervating the skeletal musculature.

So, from the cervico-brachial plexus depart the ulnar, radial, median nerves, innervating the muscles of the hands. From the lumbosacral plexus depart the sciatic, femoral and other nerves, innervating the muscles of the legs.

As the nerves come out of the spine through certain intervertebral foramen, the roots are lengthened.

Therefore, the direction of the roots is not the same: in the cervical region they move almost horizontally, in the thoracic down the slanting downward, in the lumbosacral - straight down.

Below the second lumbar vertebra, the spinal cavity is filled with a bundle of roots that descend parallel to each other and create a so-called pony tail.

Both rootlets (anterior and posterior), adjacent to each other, are directed to the intervertebral foramen and, joining in the area of ​​the intervertebral foramina, form on each side mixed spinal nerves. The posterior root, at the point of its connection with the anterior one, has a thickening - the spinal node, where the bodies of the afferent neurons are located.

Outside, the brain is covered with three membranes that develop from the mesenchyme. A soft, or vascular, shell contains the branching of the blood vessels, which then enter the spinal cord. It has two layers: the inner, fused with the spinal cord, and the outer one.

The web is a thin connective tissue plate. Between the arachnoid and soft membranes is subarachnoid (lymphatic) space, filled with cerebrospinal fluid. A hard shell is a long, spacious bag that surrounds the spinal cord.

The rostral-hard shell of the spinal cord fuses with the edges of the large occipital orifice, and the caudal end at the level of the second sacral vertebra.

The hard shell is connected with the arachnoid in the region of the intervertebral openings on the spinal nodes, as well as at the attachment points of the dentate ligament.

Toothed ligament is a thin and strong paired plate that starts from the lateral surface with a soft the spinal cord, in the middle between the exit of the anterior and posterior roots and, laterally, divides into teeth. The teeth with their apexes reach both a cobweb and a hard shell. Toothed ligament, as well as the contents of the epidural, subdural and lymphatic spaces protect the spinal cord from damage.

The internal structure of the spinal cord can be studied in a transverse section. Considering such a cut, we will see that the spinal cord is also formed from gray and white substances. The gray matter on the cut is in the form of a Latin letter H or a butterfly.

In the center of the gray matter passes a spinal canal (ingrown in humans), which in the brain expands and forms the cerebral ventricles. The protrusions of gray matter are called horn of the spinal cord.

Front protuberances, broader and shorter, are called the anterior horns of the spinal cord, posterior, elongated, posterior horns, lateral protrusions form lateral horns.

The tip of the horn is formed by special small cells and fibers, often not coated with myelin, the so-called Rolando gelatinous substance. The belt zone adjoins it. On the periphery of the rear horn lies the marginal zone (the Lissauer zone).

The rear horn includes the rear sensitive roots, from the anterior horn the front motor roots exit, heading toward the muscles. In the lateral horns nuclei of the vegetative nervous system are laid.

Cervical spinal cord cut:

• Kr blood vessels, arteries and vein;
• CI - anterior median slit;
• I - front cable;
• II - lateral cord;
• III - back cord;
• B - a bundle of Burdach;
• Γ is the Gaull bundle; PC.
• - front roots;
• Z.K. - Back roots; M.O.
• - soft shell;
• K is the central channel;
• РI - the forward horn;
• PII - rear horn;
• СII - posterior median furrow;
• CIII - posterior intermediate groove

The gray matter of the spinal cord is surrounded by a white substance consisting of myelin fibers, which form special bundles, here called the pillars.

Distinguish conductors ascending, or centripetal (afferent), transmitting sensitive impulses from the periphery to the brain, and descending or centrifugal (efferent), conducting motor impulses from the cortex and other parts of the brain to the dorsal the brain. Centripetal pathway in the rear and side columns, centrifugal - in the front and side.

The function of gray matter is the transfer of sensitive impulses to the motor receptors of the spinal cord. Thus, the stimulation of the external environment from the endings of the skin sensitive receptors along the sensitive nerve is transferred to the intervertebral node, and then through the posterior spine to the posterior horn of the spinal cord.

Further transfer of sensitive impulses to the motor device (anterior horn) is carried out either directly or through the insertion neuron. As a result of the arrival of sensitive impulses, motor impulses appear that are directed along the motor roots and nerves to the muscles, which, when cutting, produce certain movements. Thus, at the level of the spinal cord a simple reflex arc is realized, which is one of the types of spinal automatisms.

Scheme of excitation from the skin through the spinal cord to the muscles (reflex arc):

1. 1 - posterior spine;
2. 2 - intervertebral node;
3. 3 - the body of the perceiving neuron;
4. 4 - front spine;
5. 5 - the body of the motor neuron

The second half of the reflex process refers to the so-called conductor activity of the spinal cord, which carries out further transmission sensitive impulses from the joints, ligaments, muscles in the subcortical formations and the cerebral cortex through a system of ascending (centripetal) ways. Thus, the higher section of the cortex receives signals about the state at the periphery.

In turn, the cerebral cortex gives reciprocal impulses directed toward the peripheral motor receptors and muscles through the system of descending (centrifugal) pathways, by regulating the expedient motor acts. A number of important vegetative centers are laid along the gray matter of the spinal cord.

So, in the upper cervical segments the centers regulating the activity of the diaphragm are laid, in the VIII segment the center is laid, which widens the pupil. In the lower part (lumbosacral), vegetative centers that regulate the activity of the bladder and rectum, as well as genital organs, are laid.

A source: http://biofile.ru/bio/21834.html

Spinal nerves

Anatomy Nervous system Peripheral nervous systemCervical nerves Thoracic nerves Lumbar nerves Sacral nerves The coccygeal nerve The posterior branches of the spinal nerves The anterior branches of the spinal nerves The lumbar, sacral and coccygeal nerves. 996. Spinal nerves, nn. spinales; front view (diagram). Fig. 995. Segment of the spinal cord (semimetric). Fig. 997. Projection of spinal roots and nerves on the vertebral column (diagram).

Spinal nerves, nn. spinales(Fig. 995, 996, 997), are paired (31 pairs), metamerally located nerve trunks:

1. Cervical nerves, nn. cervicales (CI-CVII), 8 pairs
2. Thoracic nerves, nn. thoracici (ThI-ThXII), 12 pairs
3. Lumbar nerves, nn. lumbales (LI-LV), 5 pairs
4. Sacral nerves, nn. sacrales (SI-SV), 5 pairs
5. The coccygeal nerve, n. coccygeus (CoI-CoII), 1 pair, rarely two.

The spinal nerve is mixed and is formed by the fusion of two roots belonging to it:

1) the posterior spine [sensitive], radix dorsalis [sensoria], and

2) anterior spine [locomotive], radix ventralis [motoria].

Each root is connected to the spinal cord by root threads, fila radicularia.

The posterior root in the region of the posterolateral groove is connected to the spinal cord by root roots of the posterior root, fila radicularia radicis dorsalis, and the anterior spine in the anterolateral fissure region with root roots of the anterior root, fila radicularia radicis ventralis.

The posterior roots are thicker, as each of them has a spinal node [sensory], ganglion spinale [sensorius]. The exception is the first cervical nerve, in which the anterior spine is larger than the posterior. Sometimes there is no node in the root of the coccygeal nerve.

The front roots of the nodes do not. In the place of formation of the spinal nerves, the anterior roots only adhere to the spinal nodes and connect to them with the help of connective tissue.

The connection of roots in the spinal nerve occurs laterally from the spinal node.

Spines of the spinal nerves pass first in the subarachnoid space and are surrounded directly by the soft medulla. Between the anterior and posterior roots in the subarachnoid space is a dentate ligament.

Near the intervertebral openings the roots are densely covered with all three medullary membranes, which coalesce with each other and continue into the connective tissue sheath of the spinal nerve (see Fig. Fig. 879, 954, 956).

Spines of the spinal nerves are sent from the spinal cord to the intervertebral foramen (see Fig. Fig. 879, 997):

1) the roots of the upper cervical nerves are located almost horizontally;

2) the roots of the lower cervical nerves and the two upper thoracic spines go from the spinal cord obliquely downwards, Before entering the intervertebral foramen, one vertebra below the site of the dorsal brain;

3) the roots of the next 10 thoracic nerves follow even more obliquely downwards and, before entering the intervertebral foramen, are approximately two vertebrae below their origin;

Separating from the horse's tail, the roots are directed to the outside and are connected in the spinal canal to the trunk of the spinal nerve, truncus n. spinalis.

Most spinal nodes lie in the intervertebral openings; the lower lumbar nodes are partially located in the vertebral canal; Sacral nodes, except the last, lie in the vertebral canal outside the dura mater.

The spinal nodule of the coccygeal nerve is located inside the cavity of the dura mater. Spines of spinal nerves and spinal nodes can be studied after opening the vertebral canal and removing arches of vertebrae and articular processes.

All trunks of the spinal nerves, with the exception of the first cervical, fifth sacral and coccygeal nerves, lie in the intervertebral holes, while the lower ones, taking part in the formation of the horse's tail, are also partially in the vertebral channel.

The first cervical spinal nerve (CI) passes between the occipital bone and the 1st cervical vertebra; eighth cervical spinal nerve (СVIII) is located between VII cervical vertebra and I thoracic vertebra; the fifth sacral and coccygeal nerves exit through the sacral crevice.

Fig. 1060. The course of fibers of the spinal nerves and their relationship to the sympathetic trunk (scheme).

The trunks of the spinal nerves are mixed, that is, carry sensitive and motor fibers. Each nerve upon exiting the spinal canal is almost immediately split into the anterior branch, r.ventralis [anterior], and the posterior branch, r. dorsalis [posterior], in each of which there are both motor and sensitive fibers (see Fig. Fig. 880, 955, 995, 1060). The trunk of the spinal nerve by means of connecting branches, rr.

communicantes, is associated with the corresponding node of the sympathetic trunk.

The connecting branches are two. One of them carries pre-spill (myelin) fibers from the cells of the lateral horns of the spinal cord.

It is white [these branches are from the eighth cervical (СVIII) to the second-third lumbar (LII-LIII) spinal nerve] and is called the white connecting branch, r. communicans albus.

Another connective branch carries the post-node (predominantly bezmielinovye) fibers from the nodes of the sympathetic trunk to the spinal nerve. It is darker in color and is called the gray connecting branch, r. communicans griseus.

The meningeal branch returns to the vertebral canal through the intervertebral foramen.

Here the nerve is divided into two branches: a larger one, going along the front wall of the channel in the ascending direction, and a smaller one going in the descending direction.

Each of the branches connects both with the branches of the neighboring branches of the medulla, and with the branches of the opposite side.

As a result, a brachial plexus is formed, which sends a branch to the periosteum, bones, spinal cord envelopes, venous vertebral plexuses, and to the arteries of the spinal cord. In the neck region, spinal nerves take part in the formation of the vertebral plexus, plexus vertebralis, around the vertebral artery.

The posterior branches of the spinal nerves

Fig. 1029. Areas of skin nerve torso distribution; rear view (semiclassically). Fig. 1027. Intercostal nerves, arteries and veins; top view and a little front.

(The integuments of the anterolateral breast divisions within V-VI ribs are removed, the pleural membrane sheet and the thoracic fascia are removed.)

Posterior branches of spinal nerves, rr. dorsales nn. spinalium(cm. Fig. 995, 1027, 1029), with the exception of the two upper cervical nerves, much thinner than the anterior ones.

All the posterior branches from the site of their retreat, at the lateral surface of articular processes of the vertebrae, are guided back between the transverse processes of the vertebrae, and in the sacrum pass through the dorsal sacral holes.

Fig. 1028. Nerves of the trunk. (Rear surface). (Back branches of the spinal nerves: on the left - cutaneous branches, on the right - muscular.)

Each posterior branch is divided into a medial branch, r. medialis, and on the lateral branch, r. lateralis.

Fig. 995, 1027, 1028).

Anterior branches of spinal nerves

Anterior branches of spinal nerves, rr. ventrales nn. spinalium, thicker than the posterior ones, except for the first two cervical nerves, where there are inverse relations.

The anterior branches, except for the thoracic nerves, near the spinal column, are widely interconnected and form plexus, plexus.

From the anterior branches of the thoracic nerves take part in the wreath of the branch from ThI and ThII, sometimes ThIII (brachial plexus), and from ThXII (lumbar plexus).

However, these branches only partially enter into the plexus.

Fig. 998. Cervical plexus, plexus cervicalis (semi-schematic).

Topographically distinguish the following plexus: cervical; shoulder; lumbosacral, in which the lumbar and sacral are distinguished; coccygeal (see Fig. Fig. 998).

All these plexuses are formed by joining the corresponding branches in the form of loops.

Cervical and brachial plexus are formed in the neck, lumbar - in the lumbar region, sacral and coccygeal - in the cavity of the small pelvis.

The branches branch off from the plexuses, which are directed to the periphery of the body and, branching, innervate the corresponding sections of the body.

The anterior branches of the thoracic nerves, which do not form plexuses, continue directly on the periphery of the body, branching in the lateral and anterior sections of the walls of the chest and abdomen.

Lumbar, sacral and coccygeal nerves

Lumbar, sacral and coccygeal nerves, nn. lumbales, sacrales et coccygeus, like all overlying spinal nerves, they give out four groups of branches: meningeal, connecting, front and back.

The anterior branches of the lumbar, sacral and coccygeal spinal nerves (LI-LV, SI-SV, CoI-CoII) form one common lumbosacral sacral plexus, plexus lumbosacralis.

In this plexus, the lumbar plexus (ThXII, LI-LIV) and the sacral plexus (LIV-LV-CoI) are topographically distinguished. The sacral plexus is divided into the sacral plexus proper and the coccygeal plexus (SIV-CoI, CoII) (see Fig. Fig. 997).

A source: http://spina.pro/anatomy/nervnaja-sistema/perifericheskaja-nervnaja-sistema/spinnomozgovye-nervy/

Spinal cord - anatomy, nervous system, neuralgia of the intercostal nerve

The human nervous system is under the control of two important formations - the brain and spinal cord. The brain is located in the cranium, and the dorsal in the spine.

This formation is represented in the form of a white cylindrical strand that extends from the brainstem to the initial lumbar vertebrae, while narrowing and ending with the "ponytail".

The average length of the adult spinal cord is 40 - 45 cm. At what at men he usually is longer and reaches 45 sm whereas for women varies within 40-42 sm.

The thickness can reach no more than, cm, and weigh up to 35 g. It depends on the individualities of the spinal cord and its anatomy.

What is the spinal cord?

Like a cylindrical body, the spinal cord has 4 surfaces:

• Front, which is slightly flattened;
• Posterior protruding;
• 2 lateral, almost round, turning into the antero-posterior surface.

In the structure of the spinal cord, several parts are distinguished:

1. Neck;
2. Thoracic;
3. Lumbar;
4. Sacrificial;
5. Coccygeal.

And he himself has several main components:

• Brain canal;
• The cavity, which is filled with liquor;
• Spinal nerves;
• Vascular network of arteries of different calibers.

In this case, each of the parts has segments - the structural and functional units of the spinal cord.

Each such unit is represented by a limited area with 2 pairs of nerve roots emerging from it - front and rear.

Thus, only 31 pairs of such roots are identified throughout the spinal cord, corresponding to 31 pairs of spinal nerves and 31 segments, of which:

1. Neck - 8;
2. Thoracic - 12;
3. Lumbar - 5;
4. Sacral - 5;
5. Coccygeal - 1-3.

The white cord occupying the spinal canal is surrounded by 3 shells:

• Internal soft or vascular, which is separated from the next shell by subarachnoid, in another way, a subarachnoid space containing a cerebrospinal fluid or cerebrospinal fluid in an amount of about 100-200 ml. This allows the exercise of trophic, that is, nutritional and protective functions of the brain. This shell is the first defense of the brain from damage;
• The average arachnoid is separated from the outer casing by the lateral space;
• The outer solid is separated from the periosteum of the spinal column by an epidural space filled with the venous plexus, as well as fatty tissue.

In the spinal cord there are two thickenings:

1. Cervical, located on the border between 3 cervical and 1 thoracic vertebra;
2. Lumbosacral, located between 10-12 thoracic vertebrae.

Thickening has a physiological nature. They fall precisely on the places of greatest stress on the end of the nerves - the neck and lower back.

Functional significance of the spinal cord

In the human body, the spinal cord is of paramount importance, since it is one of the main controllers of the activity of the nervous system.

In the middle of the white strand the median slit extends from the front, and behind the furrow, with which the spinal cord is divided into two symmetrical halves.

In the work of the spinal cord, two functions are considered to be the most important:

• Reflex, which exists due to nerve centers. As a result, a reflex network is created that allows the spinal cord to be used with the help of receptors - special trapping formations, receive information from the skin and the motor system, the circulatory network and the digestive tract, excretory and sexual system. The received information is transformed into impulses and goes to muscles and organs, vessels and glands, carrying out a reflex reaction;
• The conductor function is possible due to the presence of an ascending and descending conductive path. The ascending path is able to transmit signals from the tactile, painful and temperature receptor apparatus of the skin and muscles through the cells of the spinal cord to the rest of the nervous system. A downward conducting path connects the cerebral cortex with the dorsal cortex.

The internal structure of the spinal cord has its own unique features. The white cord itself is represented by gray and white matter. Gray consists of neurons - nerve cells, which number about 13 million. This substance is located in the center and looks like a butterfly.

It forms 3 pillars of gray in each of the 2 symmetrical halves of the brain: the front post, the back and the side. Considering the brain from the transverse side, it can be noted that each of the pillars has the form of a horn. In this case, the front horn is wider, and the posterior horn is narrower.

The lateral has an intermediate form.

Around the gray, concentrated white matter of the brain, consisting of nerve fibers, located in the longitudinal direction and combined into bundles.

This kind of matter is united by the concepts of anterior, lateral and posterior cord, in which the conducting paths pass.

Thus, the front cord carries in itself a descending, lateral - ascending and descending, and the back - the ascending path.

In total, 3 systems of conducting pathways are isolated in the spinal cord. With the help of them, the connection of the spinal cord and the brain, as well as the parts of the spinal cord, is realized.

So, associative short paths allow communicating the work of the spinal cord between its segments. The ascending sensory pathways unite the dorsal and the center of the brain.

The descending motor way allows to connect the brain with the motor center of the dorsal.

Spinal nerves closely unite the nervous system and the spinal cord. As a result, they allow the brain to carry out nervous activity in the form of:

• Sensitive innervation of the entire trunk and its limbs, grasping partially the neck;
• Motor, affecting all the muscles of the trunk and its limbs with the grip of the muscular group of the neck;
• Sympathetic innervation;
• Parasympathetic organs of the pelvic group.

The spinal cord, like a mighty tree, gives a series of branches - nerves of the spinal cord, giving off even smaller twigs. These branches also include the posterior ones coming from the posterior surface of the trunk.

There they are subdivided into pectorals with a segmental structure, another name is intercostal. This name they received in connection with their location.

These nerves are involved in controlling the reactivity of the skin, as well as the muscles of the chest and abdomen.

Intercostal neuralgia

Among diseases of the nervous system and, in particular, the spinal cord, the most common is the involvement of the intercostal nerves.

According to the statistics of the causes of chest pain, this type of lesions takes a leading position. Most often, such a pathology occurs among the elderly or young people who spend a lot of time sitting.

Such a disease can affect children, especially at a time of intense growth.

The causes that give rise to intercostal neuralgia are known to be quite a lot. However, one way or another, each of them is reduced to two main:

1. Irritation or pinching of intercostal nerves in the intercostal space;
2. Pinched roots of spinal nerves in the thoracic parts of the spinal canal. Usually occurs against a background of osteochondrosis of the thoracic spine, ankylosing spondylitis or Bechterew's disease, spondylitis, intervertebral hernia or progressive kyphosis.

To lead to these reasons can spastic reduction of the diaphragmatic and intercostal muscle group due to injuries, increased level of physical activity without a previous warm-up or psychoemotional stress factor a. Also, the cause can be inflammation of the external and internal intercostal muscles due to hypothermia and infectious processes.

Much less frequently there are cases of intercostal neuralgia due to the following group of diseases:

• Food toxicoinfection by type of acute gastroenteritis;
• Spondylopathy;
• Diseases of ribs and deformations of the chest;
• Allergic diseases;
• Toxic or alcoholic polyneuropathy;
• Diabetes mellitus;
• Diseases of the gastrointestinal tract leading to vitamin B deficiency - chronic gastritis and colitis, hepatitis and peptic ulcer of the stomach or duodenum;
• Aneurysms of the thoracic part of the aorta.

The symptomatic picture of intercostal neuralgia consists of the following:

1. Pain syndrome, which stretches along the course of the corresponding intercostal space. Pain sensations can be of different intensity, as constants of medium strength, and relatively rare, arising sharply, sharply, with a pronounced and shooting character. Painful sensations increase during the movements of the patient, can increase during coughing and sneezing, and also simply by breathing;
2. Forced position due to severe pain. In this case, a person tries to lean toward the side of the lesion to minimize the volume of movements and reduce pain, respectively. It can be observed that the patient is pressed to the affected intercostal space by sneezing or coughing;
3. Feeling of burning, tingling or numbness in the intercostal space;
4. The spread of pain to the left side of the body, which often leads to confusion and the acceptance of neuralgia for angina pectoris. Pain is given to the left arm or shoulder blade, as well as to the left side of the spine. In order not to confuse such similar symptoms, it should be remembered that pain in angina is independent of movements and coughing, sneezing and laughing. Among other things, it is reduced by the intake of nitroglycerin. However, doubtful cases require mandatory ECG, as there is a possibility of confusion neuralgia of the intercostal nerve with myocardial infarction, in which the pain syndrome does not go away after taking nitroglycerin.

Treatment and prognosis of neuralgia of intercostal nerves

Treatment of patients with intercostal neuralgia is aimed at the removal of pain and treatment of the disease, against which neuralgia arose.

Depending on the degree of severity, patients are shown bed rest.

At what it is desirable, that the mattress on which the patient lay was orthopedic or simply equal and hard, since a soft and sagging mattress can only worsen an already grave condition patient.

Among the medicines, such patients are most often prescribed systemically:

• Non-steroidal anti-inflammatory drugs such as Meloxicam, Diclofenac, Rofecoxib. These drugs ease the pain syndrome and have an anti-inflammatory effect. They can be prescribed as injections, tablets or suppositories, that is candles;

• Miorelaksiruyuschie means, which include Midokalm, Tolperil and Sirdalud. These drugs can reduce muscle spasm;
• Sedatives, that is, have a calming effect. They include Sedasen, Persen, Novopassit;
• Vitamin B, which is a part of various drugs - Neurobion, Neurorubin, Milgamma. Their action is aimed at the restoration of damaged nerve structures, which improves the transfer of momentum between them.

In addition to systemic treatment aimed at improving the overall condition, local therapy is also provided. Such treatment is directed primarily at the specific site of the lesion. Local therapy consists of application:

1. Dry heat to the affected area in the form of a source of indirect heat, such as a knitted or woolen thing. The impact of hot objects can cause not so much good as harm. So, in the beginning there is an activation of the local blood flow, and then as the object cools, weakening it, which leads to an increase in edema and increased pain;
2. Ointments and gels containing NSAIDs are non-steroidal anti-inflammatory drugs. To such group of means carry Dolobene and Fastum-gel;
3. Ointments and gels with anesthetics and compounds with a reflex action of the type Menovazine, Kapsikama, Finalgona;
4. Transdermal patches, which are a relatively new method of topical treatment. These patches contain anti-inflammatory and anesthetic substances, which when attached to the affected area of ​​the intercostal space, begin to gradually release their compounds. Thus, it is a positive effect on the area of ​​the affected nerve. Among the patches are especially popular Voltaren, as well as Nanoplast forte.

Medication therapy is not the only treatment option. Of course, with the help of medicines, it is possible to remove the immediate cause that led to neuralgia. However, after the disappearance of acute pain, a rapid recovery is possible by:

• Therapeutic massage, which leads to improved metabolism in muscles, reduces pain and swelling, and also leads them into a normal tone;

• Physiotherapy exercises aimed at strengthening the muscles of the spinal column;
• Manual therapy, which facilitates the normalization of connections between the vertebrae, as well as the removal of strangulated nerves;
• Acupuncture;
• Physioprocedures performed with the help of special medical devices. Such procedures include magnetotherapy, laser therapy, electrophoresis and UHF.

Since intercostal neuralgia is a polytheological disease, that is, the causes that cause it a large number, specific prevention to its occurrence is simply absent.

In order to prevent its occurrence, it is necessary to timely treatment of diseases, the consequence of which it is. It also helps to avoid its lack of excessive physical exertion and hypothermia.

Timely exposed diagnosis - intercostal neuralgia, allows you to start the necessary treatment on time. Such patients often expect full recovery with the restoration of all functions.

A source: http://umozg.ru/struktura/spinnoj-mozg-anatomiya.html