Sympathetic and parasympathetic departments of the vegetative nervous system. Vegetative Nervous System of Human: Sympathetic Parasympathetic System Centers

According to the morphofunctional classification, the nervous system is subdivided: on somaticand Vegetative.

Somatic nervous systemprovides perception of irritation and carrying out motor reactions of the body as a whole with the participation of skeletal muscles.

Vegetative nervous system (VNS) Innervates all internal organs (cardiovascular system, digestion, breathing, sex, allocations, etc.), smooth muscles of hollow organs, regulates metabolic processes, growth and reproduction

Autonomous (Vegetative) Nervous System regulates the functions of the body regardless of the will of the person.

The parasympathetic nervous system is the peripheral part of the autonomic nervous system, responsible for maintaining the constancy of the inner environment of the body.

Parasympathetic nervous system consists of:

From the cranial department, in which the pregganionic fibers leave the average and diamond-shaped brain in the composition of several cranopy brain nerves; and

From the sacred department in which the pregganionic fibers extend from the spinal cord in the composition of its ventral roots.

Parasympathetic nervous system brakes Heart work, expands some blood vessels.

The sympathetic nervous system is the peripheral part of the vegetative nervous system, which ensures the mobilization of resources available from the body to perform urgent work.

The sympathetic nervous system stimulates the work of the heart, narrows blood vessels and enhances the performance of skeletal muscles.

Sympathetic nervous system is presented:

Gray substance side horns of the spinal cord;

Two symmetric symptomatic trunks with their ganglias;

Interstitial and connecting branches; as well as

Branches and ganglias involved in the formation of nervous plexuses.

All vegetative NA consists of: parasympathetic and sympathetic departments. Both of these departments innervate the same organs, often providing them with the opposite effect.

The terminations of the parasympathetic department of the vegetative NA, the acetylcholine mediator is distinguished.

Parasympathetic department of vegetative nsregulates the operation of the internal organs in rest. Its activation helps to reduce the frequency and force of heart rate, reduce blood pressure, increasing both the motor and the secretory activity of the digestive tract.

The endings of sympathetic fibers are isolated as a noraphenilin and adrenaline mediator.

Sympathe Department of Vegetative NA increases its activity if necessarymobilization of the body's resources. The frequency and strength of heart abbreviations increases, the clearance of blood vessels is narrowed, blood pressure increases, the motor and secretory activity of the digestive system is inhibited.

The nature of the interaction between the sympathetic and parasympathetic departments of the nervous system

1. Each of the sections of the vegetative nervous system can have an exciting or braking effect on this or another. For example, a heartbeat is studied under the influence of sympathetic nerves, but the intensity of intestinal peristals is reduced. Under the influence of the parasympathetic department, the frequency of heart abbreviations is reduced, but the activity of the digestive glands increases.

2. If any organ is innervated by both vehicle university departments, then their action is usually exactly opposite. For example, the sympathetic department enhances heart cuts, and parasympathetic relaxes; Parasympathetic increases the secretion of the pancreas, and sympathetic reduces. But there are exceptions. So, the secretory nerves for the salivary glands are parasympathetic, while the symptic nerves do not slow down the salivation, but cause the allocation of a small amount of thick viscous saliva.

3. To some organs, they are mostly either sympathetic or parasympathetic nerves. For example, a sympathetic nerves are suitable for the kidneys, spleen, and the urinary bubble is predominantly parasympathetic.

4. The activities of some organs are managed only by one department of the nervous system - sympathetic. For example: when activating the sympathetic department, the sweating is amplified, and when the parasympathetic activation does not change, the sympathetic fibers increase the reduction of smooth muscles, lifting hair, and parasympathetic does not change. Under the influence of the sympathetic department of the nervous system, the activity of some processes and functions may vary: the blood coagulation is accelerated, the metabolism increases more intensively, mental activity increases.

Reactions of the sympathetic nervous system

The sympathetic nervous system, depending on the nature and force of irritation, corresponds to either the simultaneous activation of all its departments or reflex responses of individual parts. The simultaneous activation of the entire sympathetic nervous system is observed most often when activating the hypothalamus (fright, fear, unbearable pain). The result of this extensive reaction covering the whole body is a stress reaction. In other cases, certain departments of the sympathetic nervous system are activated reflexively and with the involvement of the spinal cord.

The simultaneous activation of most sections of the sympathetic system helps the body produce unusually large muscular work. This is facilitated by an increase in blood pressure, blood flow in working muscles (with a simultaneous decrease in blood flow in the gastrointestinal tract and kidneys), increasing the speed of metabolism, glucose concentration in blood plasma, glycogen cleavage in the liver and muscle, muscle strength, mental performance, blood coagulation speed . The sympathetic nervous system is very excited in many emotional states. In the state of rage is stimulated by the hypothalamus. Signals are transmitted through the reticular formation of the brain barrel in the spinal cord and cause a massive sympathetic discharge; All the above reactions are incorporated immediately. This reaction is called a sympathetic alarm reaction, or a fight or flight response, because An instant decision is required - to stay and enter into battle or run.

Examples of reflexes of the sympathetic department of the nervous system are:

- expansion of blood vessels with local muscular reduction;
- Potting when heating the local area of \u200b\u200bthe skin.

A modified sympathetic ganglia is a brain layer of adrenal glands. It produces adrenaline hormones and norepinephrine, the points of the application of which are the same target organs as for the sympathetic unit of the nervous system. The effect of cerebral cerema hormones is more pronounced than the sympathetic department.

Reactions of the parasympathetic system

The parasympathetic system carries out local and more specific control of the functions of effector (executive) organs. For example, parasympathetic cardiovascular reflexes usually act only on the heart, increasing or reducing the frequency of its abbreviations. Other parasympathetic reflexes also act, causing, for example, salivation or secretion of gastric juice. Reflex emptying rectum does not cause any changes at a considerable distance of the colon.

Differences in the influence of the sympathetic and parasympathetic departments of the autonomic nervous system are due to the peculiarities of their organization. Sympathetic postganglyonary neurons have an extensive innervation zone, and therefore their excitement usually leads to generalized (widespread) reactions. The overall effect of the influence of the sympathetic department consists in braking activities of most internal organs and stimulation of cardiac and skeletal muscles, i.e. In the preparation of the body to behave type "struggle" or "escape". Parasympathetic postganglyonic neurons are in the organs themselves, innervate limited areas, so they have a local regulatory effect. In general, the function of the parasympathetic department consists in regulation of processes that ensure the restoration of the functions of the body after active activity.

In a segmental ap-parat of the parasympathetic nervous system (Fig. 1.5.2), three deposits are distinguished: a spinal (sacred), bulbar and mezentcephalus. Reggangionary parasympathetic neurons are located here. Postgangylionic neurons are in the Viso ceral nodes (the top C lower mesenter, curly), nodes of organ vegetative plexuses and vegetative assemblies of the person (eyelashes, ear, Cry-Lona, subband, sub-public - see Fig.1.5.2).

Sleepy

The preggaeer-Ron of the sacrum of the pa-rasimpathic nervous system is represented in the RU-DIMENS of the side horns of S III-V, the axons overlook the front of the front roots and further as part of the pelvic nerve.

Switching to post-ganglionary neuron occurs in the nodes of vegetative plexuses of inner-virked organs - no-converging and direct kish-ki. bladder, organ-new genitals.

Bulbarium

The pulbiary department of the parasympathetic nervous system is represented by several nuclei (preggangonary neurons). The main one is a dorsal core of a wandering nerve, from where in the neuro and its branches, the impulse is sent to the innervored authorities: the trachea, bronchoms, heart, abdominal organs.

Switching to postganglyonic neurons, as mentioned above, occurs in visceral and organ-nodes. The irritation of the wandering nerve causes a slowdown in the pulse, hyperemia of the face, a decrease in blood pressure, bronchospasm, strengthening the peristalticity of the gastrointestinal tract, increasing the diuresis. The loss of the influence of the vagus nerve leads to opposite phenomena due to the prevalence of sympathetic influences.

Medulla

In the oblong brain there is also a pair bottom salivary core attributed to a cogllic nerve. And indeed, the preggling fibers occurring from it take place in the composition of the coglotor nerve and its branches - the drum and small rocky nerves, and then an earnest nerve (ve-dot of the 1st branch of the trigeminal nerve) to the ear node where they switch to postganglyionary Fibers, inner-virifying parish gland.

It is known for the sandy hyperhydrogen syndrome (Frey Syndrome), in which due to damage to the ear-wing nerve (vapotitis, injury) and the subsequent deficient reinnervation of secretory fibers The food process is accompanied by hyperhydrosis of the near-wing-temporal o'clock, especially when using acute food.

From another parasympathetic formation of a continued brain - the upper salivary core, the pregganionic fibers are based on the rear root of the face nerve (intermediate nerve), the facetful nerve barrel in its channel, as part of its branches - the drum string and then the paternal The branches of the mandibular nerve to the subband and sub-pointed salivary glands, interrupting in the eponymous vegetative nodes on postganglyonary fibers (see Fig. 1.2.19). The defeat of this path causes dry mouth (xerostomy).

Very important parasympathetic fibers occur from one cell accumulation in the oblong brain, adjacent to the upper salivary poison, from the tear kernel. The fibers go in the rear root of the face nerve, continue in its branch - in a large rocky nerve, moving into the nerve of the ponyabot canal. As a result, they reach the Cry-Lona Knot, where postganglyonary neuron is lying, the fibers of which in the composition of the boring nerve (the branch of the maxillary), then the lacrimal nerve (the branch of the eye nerve - from the first trigeminal branch) reaches the lacrimal gland.

Tearing can be associated with eye disease (for example, conjunctivitis) or be reflex (otitis, rhinitis, etc.). Attacks of a strong personal pain, as it happens, for example, with neuralgia of a three-perch nerve, are also accompanied by reflex towes. Tearing in combination with the stamp of the nose, the rinorera is characteristic of the attack of a beam headache. Tearing on the side of the paresis of the circular muscle of the eye (neuropathy of the face-throat) is associated with a disruption of the suction function of the lacrimal canal. Elder tear is also explained by the hypotension of this muscle.

In other cases, on the contrary, one-sided dryness of the eye (xerofthalmia) occurs. This is usually observed in the neuropathy of the facial nerve with the defeat of its sec-retor fibers (rear root, the trunk before the exhaustion of a large stony nerve), which can lead to eye infection. Bilateral dry eye in co-quencing with anhydrosis, dryness in the mouth is characteristic of "dry syndrome" Shegon or for progressive peripheral failure. It may also be a manifestation of Mikulich's syndrome: an increase in the tear and salivary glands, combined with the disruption of their secretory function.

Mezentcephalus department

The mesenteflastic department of the parasympathetic nervous system is represented by small-cell cores of the III pair of cranial nerves (pregglicionary neurons) and the median unpaired core.

Peripheral neuron is in the front horns of the lower-friendly segments of the spinal cord, the fibers reach the sphincter in the composition of the pelvic nerve. The affect of paracentral rally (parasagittal tumor) is characterized by double-sided parallers of the feet and the non-holding urine (see Fig. 1.2.9).

Types of pelvic disorders

Three main types of neurogenic tall disorders can be distinguished, the most demonstrative in relation to the bladder dysfunction.

1. Under the defeat of the arbitrary control of the bladder of the bladder, it is assumed as part of the pyramidal path) there are difficulties of arbitrary control, imperative urge arise (the impossibility of arbitrary full control of urinary urges), which is usually combined with the difficulty of emptying the urine bubble (the patient is accounted for For a long time). It can prevail both both and other influence. With a complete loss of arbitrary control of urine-changing, the phenomenon of the so-called autonous bladder occurs when periodically, as the bladder fill, its reflexion of emptying occurs (Incontinentia Intermittens). Most often, this is observed in patients with scattered skeleton (cerebrospinal and spinal shapes).
2. In case of incomplete lesion (irritation) of the sacral segments or their roots associated with the innervation of the bladder, the spasband of the bladder sphincters can develop. The bladder is full, and urine is highlighted by drops (Ischuria Paradoxa).

(From the Greek word Para - against, contrary to.)

The parasympathetic nervous system (Fig. 321) is the part of the autonomic nervous system, the fibers of which begin in the middle brain (bottom of the brain water supply), oblong (diamond-shaped pumped), and in the sacratsum of the spinal cord (from the II to the IV sacral segment). Pregganionic parasympathetic fibers, as well as sympathetic, on the outlet of the brain are interrupted in the cells of parasympathetic nodes. But while the ganglia of the sympathetic system was located away from the innervated organs, the ganglia of the parasympathetic system is most often located in the walls of innervated organs - in intramural nodes, and short postganglionic fibers are already in depth organs.

Figure 321. The scheme of the location of parasympathetic centers in the head and spinal cord. Parasympathetic fiber stroke diagram in III, VII, IX and X nerves; VII - facial nerve; IX - Language nerve; X is a wandering nerve. 1 - medium brain; 2 - Cranial part of parasimpatikus; 3 - oblong brain; 4 - sacred part (S II, S III, S IV) parasimpatikus; 5 - nerves to the pelvis organs; 6 - grade plexus (nerves for the rectum, bladder, genitals); 7 - solar plexus (nerves in the stomach, intestines, liver, pancreas, kidneys, adrenal glands, spleen); 8 - nerves to heart, bronchoms (light); 9 - submandibular and subulter nodes (nerves for submandibular and sub-banding glands); 10 - drum string; 11 - ear node (nerves to the parole); 12 - Basic-sky node (nerves for tear glands); 13 - eyebuilding knot (nerves to the compressor pupil, ciliary muscle)

In addition to anatomical, sympathetic and parasympathetic systems have other differences; The endings of sympathetic wolves as a carrier (mediator) pulses to the organs are distinguished by sympathies, parasympathetic - acetylcholine.

Parasympathetic centrifugal fibers, originate from the nerve cells lying on the middle brain, are in the composition of the eye nerve. They are sent to the smooth muscles of the eye and innervate the muscle, the narrowing pupil, and the ciliary (accommodative) muscle of the eye. The fibers originating the beginning in the oblong brain are part of the facial, language petroleum and wandering nerves. Part of these fibers forms the intermediate nerve of the Vriesberg, which is moving along with the front nerve. This nerve gives two branches: rocky nerve and drum string. The first of them innervates the lacrimal gland, the gland of the mucous membrane of the nose and the sky, the second is sent to salivary glands, except for the paroxy gland, which innervates the parasympathetic fibers of the Language nerve.

Numerous parasympathetic fibers, originating in the bottom of the diamond pits and going as part of a wandering nerve, innervate a sip on the neck, esophagus, larynx, trachea, in the chest cavity - heart and light, esophagus, in the abdominal cavity - most of the abdominal bodies, for The exception of the lower intestinal departments. The branches of the wandering nerve on their way are intertwined with the branches of sympathetic nerves. Parasympathetic pregganese fibers of the vagus nerve are interrupted in numerous nodes placed in the walls of the organs themselves. Branching of the wandering nerve along with sympathetic fibers take part in the formation of a ventilator.

Parasympathetic fibers that constitute the main mass of the wandering nerve, regulate the activities of all internal organs of the chest and abdominal cavity, except the area of \u200b\u200bthe small pelvis.

The representative of the sacrilate department of the parasympathetic nervous system is a paired pelvic nerve (N. Pelvicus), participating in the formation of a gravy plexus (Plexus Hypogastricus); It innervates organs located in a small pelvis: a bladder, internal genital organs and the lower division of the large intestine.

The value of the autonomic nervous system. The vegetative nervous system (Fig. 322), as shown above, innervates all organs located in the chest and abdominal cavity, a smooth muscle of blood vessels and skin, as well as all glands, and most of our body organs receive nervous fibers from the sympathetic and parasympathetic nerve Systems, i.e. there is a double innervation. However, while the sympathetic nervous system innerves all organs, parasympathetic innervates not all organs and tissues. For example, most smooth muscle shells of blood vessels, ureters, smooth muscles of spleen, hair bags, etc. are deprived of parasympathetic innervation.

The main function of the autonomic nervous system is to regulate the activities of the organs aimed at ensuring that this activity always exactly corresponds to the continuously changing needs of the body. Such functions, as well as metabolism and thermoregulation, directly or through the inner secretion glands (thyroid gland, adrenal gland, sex glands, etc.), innervated by the vegetative nervous system, are mainly under its control.

In the activities of the vegetative nervous system, two kinds of pulses coming to a particular organ: in sympathetic and parasympathetic fibers; They are different between themselves and in a certain extent are opposite to their action. Pavlov said that the chemical life process of each tissue is regulated in its intensity by special centrifugal nerves and moreover by the principle distributed in the body, in two opposite directions. Many physiological processes in the body at first glance seem diametrically opposite, which seems to be interpreted about antagonistic relations in the body; For example, the opposite effect of potassium salts and calcium, adrenaline and acetylcholine (the effects of the sympathetic and parasympathetic system), the processes of assimilation and dissimulation, excitation and braking, etc. However, antagonism (opposition) should be understood only in a relative sense. Antagonism of biological processes in the body, like synergism, there are two sides of a general process. This is the struggle of the opposites aimed to achieve one common goal - the well-being of the body as a whole. If the bodies and individual systems had independence, absolute autonomy, then it would be possible to talk about their antagonism, about countering each other, but in a single holistic body the relationship is completely different.

The body as a single holistic system is very widely used in its vital activity oppositely acting factors. Without a sympathetic nervous system, the organism also cannot normally exist in a complex environmentally surrounding, as well as a parasympathetic system.

The law of unity of opposites here acts especially clearly. It is absolutely wrong to talk about the role of one system. During significant physical activity, a sympathetic nervous system plays a significant role, but if the parasympathetic system does not enter into action, the body does not even be able to perform a large and most importantly long work. With digestion, for example, a parasympathetic nerve is the starting mechanism - n. Vagus, but the sympathetic system is turned on after it. Thus, for the normal activity of the body, the presence of both parts of the autonomic part of the nervous system is required.

The combined effect of the sympathetic and parasympathetic system determines the clear regulation of the work of the organs that respond to all changes occurring in the body and adapt their activities to the changed conditions.

The vegetative nervous system is an inseparable part of the single nervous system of a whole body and performs its functions, like all other departments of the nervous system, under the regulatory influence of its highest department - the cortex of the brain.

General Plan of the ENS structure.

In the vegetative nervous system allocate sympathetic and parasympathetic parts. With the prevailing effect of one of them, the body reduces or, on the contrary, strengthens its work. Both are under the control of the highest departments of the central nervous system, which is achieved by their agreed effect. Vegetative centers in the head and spinal cord make up central Divisionthe vegetative nervous system, and her peripheral department Submitted: nerves, nodes, vegetative nervous plexuses.

Sympathetic centers are located in the lateral horns of the spinal cord, in its chest and lumbar segments. Sympathetic fibers are departed from their cells, which in the composition of the front roots, the spinal nerves and their branches are sent to the nodes. sympathetic trunk. Right and left sympathetic trunks Located along the entire vertebral post. They are a chain of thickens (knots), in which the bodies of sympathetic nerve cells are located. Approaching the node (ganglia) of the sympathetic barrel, the fibers come into it and end in its cells, from which the new peripheral neuron begins, which goes to the working body in the composition of vegetative nerves and plexuses.

Sympathetic fibers up to the node are the name of the precurate, or preggglyonary, and coming from the cells of the node to the periphery - postozlovy, or postgangling. Pregganionic fibers are covered with white myelin shell and form white connecting branches. Postgangylionary fibers emerging from the node do not have a myelin shell and form gray connecting branches. Sympathetic trunks, located on both sides of the spine, consist of 2-3 cervical nodes, 12 thoracic, 2-5 lumbar, 2-5 sacral and one nonparthen - spanking, which closes the chains of sympathetic barrels.

Parasympathetic innervation It is carried out by nerve cells located in the sacratsum of the spinal cord and in the brain barrel, and the first regulate the activities of organs located in a small pelvis (bladder, direct intestine and genital organs), and the cells of the head unit innervate the remaining organs through the wandering, transshipment , intermediate and eye nerves, vegetative kernels of which are located in the oblong brain, the top of the bridge (Varoliev), the middle brain.

The transition of a nervous impulse from one neuron to another or with neurons on the cells of executive (effector) organs is carried out in the contact places of cell membranes, called synapses. Information transmission is carried out by special intermediary chemicals. (mediators) secreted from nerve endings in synaptic gap. In the nervous system, these substances call neuromediators. The main neurotransmitters in the vegetative nervous system are acetylcholineandnoraderenalin.

The difference between the sympathetic and parasympathetic departments.

The sympathetic and parasympathetic departments of the RENTS differ in the location of their central and effector neurons, their reflex arcs. They differ in the same way and in their influence on the functions of innervated structures.

What are the differences in these departments? Central neurons sympathetic The nervous system is located, as a rule, in the gray substance of the side horns of the spinal cord from Th1 (breast) to L2-3 (lumbar) segments. Thus, the sympathetic nerves always depart only from the spinal cord in the composition of the spinal nerves on the front (ventral) roots.

Central neurons parasympathetic The nervous system is in the sacral segments of the spinal cord (S 2-4 segments), but most of the central neurons are in the brain barrel.

Most of the nerves parasympathetic Systems depart from the brain in the composition mixed Card - Brain Nerves . Namely:

From the middle brain as part of the III pair (ooo eye nerv) - innervating the muscles of the ciliary body and the annular muscles of the pupil eye;

From the Barolic Bridge, the facial nerve - VII pair (secretory nerve) is innervating the glands of the nasal mucosa, tear glands, submandibular and sublard glands;

From the oblong brain, Ixpara is a secretory, and a petroleum nerve, innervates the paroles of the heap and lips into the sludge gland; -X pair ( nervus vagus) - The most significant part of the parasympathetic department of VNS, passing into the chest and abdominal cavity, innervates the entire complex of internal organs.

The nerves, departing from the sacral segments (2-4 segments), innervate the organs of the small pelvis and are part of the grave plexus.

Effective neurons sympathetic The nervous system is made on the periphery and are either in paravertebral ganglia (in the sympathetic nervous chain), or exceeding. Postgangylionic fibers form various plexuses. Among them, the most important is the ventilated (solar) plexus, but it includes not only sympathetic, but also parasympathic fiber. It ensures the innervation of all organs located in the abdominal cavity. That is why there are so dangerous blows and injuries to the top of the abdominal cavity (approximately under the diaphragm). They are able to cause a shock state.

Effective neurons parasympathetic nervous system always located in the walls of the internal organs (intramaorally). Thus, in parasympathetic nerves, most of the fibers are coated with myelin shell, and impulses reach effector organs faster than that of the sympathetic.

Internal organs located in the chest and abdominal cavity are mainly innervisy wandering nerve (N. Vagus), so these influences are often called vagus.

There are significant differences in their functional characteristics.

Sympathetic the Department, usually, mobilizes the body's resources for the implementation of energetic activities (the work of the heart is enhanced, the clearance of blood vessels is narrowed and blood pressure increases, breathing is rapidly, pupils, etc.) are expanding.

Parasimpatic , on the contrary, stimulates the work of the digestive system. It is no coincidence after the satisfying lunch marks lethargy, we so want to sleep. When excited, the parasympathetic nervous system provides restorationequilibrium internal environment of the body. It provides the work of the internal organs at rest.

In the functional sense, the sympathetic and parasympathetic systems are antagonists, complementing each other in the process of maintaining homeostasis, so many organs receive double innervation - and from the side of the sympathetic, and by parasympathetic departments. But, as a rule, different people are dominated by one or another VNS department. It is no coincidence that the famous domestic physiologist L.A. Orbelli tried to classify people on this sign. He allocated three types of people:

-Simpaticotonics(with the predominance of the tone of the sympathetic nervous system) - they are distinguished by dry skin, increased excitability;

-Vagotonicwith the predominance of parasympathetic influences - for them is characterized by oily skin, slow reactions;

- Sproutering type.

L.A. The orbel believed the knowledge of these types is important for the treatment of patients, especially when prescribing doses of drugs, since the same drugs in the same dose affect patients with different types of VNS in different ways. Even from everyday practice, each of us may notice that tea and coffee cause a different reaction in people with different types of NAS functional activity. But throughout the life of a person, his type of VNS may vary depending on age, period of puberty, pregnancy and other influences. Despite the listed differences, both of these systems, however, constitute a single functional integer, since the integration of their functions is carried out at the CNS level. You already know that in the gray substance of the spinal cord the centers of vegetative and somatic reflexes are successfully adjacent, as well as they are close to each other in the brain barrel, and in the highest subcortex centers. Just like ultimately, in unity all nervoussystem .

4. The effect of sympathetic and parasympathetic innervation on the function of the body

The entire vegetative nervous system is divided into the sympathetic and parasympathetic parts, each of which performs its tasks and functions. Vegetative nervous sympathetic innervation

The sympathetic vegetative nervous system - its composition includes centers that are laid in the side horns of the spinal cord, and begin on the 3rd cervical, the 3-4 lumbar segments are completed. Sympathetic trunk with intrauterine nerves and paravertebral gangnesses involved in the formation of plexuses. Neurons in this area are involved in the innervation of the internal muscles of the eye, gloomy (salivary, sweat, greasy, etc.), lymphatic and blood vessels.

Fig. one.

The sympathetic barrel is located along the spinal column. It allocate 5 departments: cervical, chest, lumbar, sacral and tail. The left and right sympathetic trunks have sympathetic ganglia in their structure, which are connected by intergangongogenic branches.

• 1. Host the Department - It starts from the stars of the node, and departs from it in the form of 2 stems, of which the distal branch below wars the subclavian artery, while forming a connective loop, and then connects to the proximal branch. At the site of the compound of these 2 branches (proximal and distal) is the average cervical gangli. Next, the cervical trunk is directed to the cranial cervical node, where, together with a wandering nerve, to which he arrives, they form a wagosympathic trunk.
• 2.Gruda the Department - It begins from the Sheinogrutny (Star) Ganglia, and goes caudally into the abdominal cavity through the legs of the diaphragm. Several nerves depart from the star node.

The vertebral nerve comes out of the 6th cervical vertebra and goes to the 2nd cervical vertebra in the transverse tube. A branch of the cervous spinal nerves go throughout his move, and form vertebral plexus around the vertebral artery. Postganglionary fibers that are in the composition of the branches of the spinal nerves, innervate the vessels of the spinal cord and neck.

The cervical cordial nerves are sent to the heart plexus. In addition, part of the pregganionic fibers forms branches that depart from the sympathetic barrel and form a large internal nerve.

• 3.Poy the Department - It has lumbar ganglia. Lumbar internal nerves are deployed from them, which in turn enter the caudal mesenter gangli.
• 4.Crestts the Department - This is the continuation of the lumbar department and in its composition has ganglia, which are combined with each other. Branches are deployed from them, which form internal nerves.

The effect of the sympathetic department of the vegetative nervous system on various organs:

• 1) when he influenced the heart, it increases the strength of its abbreviations, and also increases the frequency of the beating;
• 2) expands the arteries;
• 3) inhibits the production of digestive enzymes and intestinal peristalsis;
• 4) relaxes the bladder;
• 5) expanding bronchi and bronchioles, pupils;
• 6) depresses salivation.

The parasympathetic department of the vegetative nervous system is as well as its sympathetic part of it in the brain stem department. In the brain he has education in the form of cores. This is a tear core, which regulates the tear, the addition core of the ooo oxide nerve, or a different core of Yakubovich and Pearlia, which is responsible for controlling the magnitude of the pupil, there are also 2 saliva-separation cores, which provides the formation of saliva, and the dorsal core of the wandering nerve affects the work of the heart, Bronchi, intestines and stomach.

All these kernels are in the brain, namely in its stem part, as well as in the sacratsum of the spinal cord. Together they constitute the entire central part of the parasympathetic department. Nervous fibers are deployed from these cores, which include III, VII, IX and X pairs of cranopy brain nerves. III pair of nerves - the fiber of the glasses, which narrow the pupil and the ciliary muscle. VII steam is a facial nerve to which parasympathetic fibers are joined in the canal of the temporal bone. They innervate sublingual and submandibular salivary glands, tear gland and gland mucosa in the oral cavity and nose. X Course is a wandering nerve, which contains parasympathetic fibers, which are departed to the organs of the neck, abdominal and chest cavity, as well as to the heart, esophagus, easy and other organs.

From the sacrum of the spinal cord, parasympathetic fibers exit consisting of sacral spinal nerves. These fibers innervate the internal bodies of the small pelvis: the bladder, the uterus, the rectum, etc.

In this department of the vegetative nervous system there are a large number of nerve nodes, which are located both behind the walls of organs and near them. Fibers emerging from the dorsal and brain are suitable for these nodes, and then the nerve fibers go to the internal organs of the body.

Effect of the parasympathetic department of the vegetative nervous system on the organs:

• 1) acting on the heart, it reduces its frequency of operation and abbreviations;
• 2) In most organs, the parasympathetic department does not affect arteries, but causes expanding the sexual arteries, the brain, as well as narrows the artery of the lungs;
• 3) stimulates salivation;
• 4) narrows pupils;
• 5) reduces organ ventilation.