Sympathetic fibers. Human autonomic nervous system: sympathetic division

The autonomic nervous system, also called the autonomic nervous system, has several divisions or parts. One of them is sympathetic. Division into departments is based on functional and morphological characteristics. Another subtype is the parasympathetic nervous system.

In life, the nervous system performs a wide range of functions, which makes its importance very high. The system itself is complex and has several departments and subtypes, each of which takes on part of the functions. The most interesting thing is that for the first time such a concept as the sympathetic nervous system appeared in 1732. Initially, the term was used to refer to the whole thing. But as the knowledge of scientists accumulated, they realized that there was a much more extensive layer hidden here, so this concept began to be attributed to only one of the subspecies.

If we consider specific values, it turns out that the sympathetic nervous system performs quite interesting functions for the body - it is responsible for the consumption of resources, as well as for mobilizing forces in emergency situations. If such a need arises, the sympathetic system increases energy expenditure so that the body can continue to function normally and perform its tasks. When we talk about hidden opportunities and resources, this is exactly what we mean. The state of the body will depend on how the system copes with this.

However, all this is a strong stress for the body, so it will not be able to function in this mode for a long time. This is where the parasympathetic system comes into play, whose tasks include restoring resources and accumulating them so that later a person can perform the same tasks, and his capabilities are not limited. Sympathetic and ensure the normal functioning of the human body in different conditions. They work inextricably and constantly complement each other.

Anatomical device

The sympathetic nervous system appears to be a rather complex and branched structure. The central part is located in the spinal cord, and the periphery connects various endings in the body. The actual endings of the sympathetic nerves are connected in numerous innervated tissues into plexuses.

The periphery of the system is formed by a variety of sensitive efferent neurons, from which special processes extend. They are removed from the spinal cord and are collected mainly in the prevertebral and paravertebral nodes.

Functions of the sympathetic system

As mentioned earlier, the sympathetic system is fully activated during stressful situations. In some sources it is called the reactive sympathetic nervous system, because it must give some reaction of the body to a situation formed from the outside.

At this moment, the adrenal glands begin to produce adrenaline, which serves as the main substance that allows a person to react better and faster to stressful situations. However, a similar situation can arise during physical activity, when, due to the adrenaline rush, a person begins to cope better with it. The secretion of adrenaline enhances the action of the sympathetic system, which begins to “provide” resources for increased energy consumption, because adrenaline only stimulates various organs and senses, but is not the actual resource itself.

The effect on the body is quite high, because after this the person experiences fatigue, weakness, and so on, depending on how long the adrenaline effect lasted and how long the sympathetic system spent resources to maintain the body's functioning at the same level.

Sympathetic department in its main functions it is trophic. It provides increased oxidative processes, increased respiration, increased heart activity, i.e. adapts the body to conditions of intense activity. In this regard, the tone of the sympathetic nervous system predominates during the day.

Parasympathetic Division performs a protective role (constriction of the pupil, bronchi, decreased heart rate, emptying of the abdominal organs), its tone predominates at night (“the kingdom of the vagus”).

The sympathetic and parasympathetic departments also differ in mediators - substances that transmit nerve impulses at synapses. The mediator in sympathetic nerve endings is norepinephrine. Mediator of parasympathetic nerve endings - acetylcholine.

Along with the functional ones, there are a number of morphological differences in the sympathetic and parasympathetic divisions of the autonomic nervous system, namely:

The parasympathetic centers are separated and are located in three sections of the brain (mesencephalic, bulbar, sacral), and the sympathetic centers are located in one (thoracolumbar section).

The sympathetic nodes include nodes of the 1st and 2nd order, and the parasympathetic nodes include the 3rd order (terminal). In this connection, preganglionic sympathetic fibers are shorter, and postganglionic fibers are longer than parasympathetic.

The parasympathetic division has a more limited area of innervation, innervating only internal organs. The sympathetic department innervates all organs and tissues.

Sympathetic division of the autonomic nervous system

The sympathetic nervous system consists of central and peripheral divisions.

Central department represented by the intermediate-lateral nuclei of the lateral horns of the spinal cord of the following segments: W 8, D 1-12, P 1-3 (thoracolumbar region).

Peripheral department The sympathetic nervous system consists of:

nodes of the 1st and 2nd order;

internodal branches (between the nodes of the sympathetic trunk);

the connecting branches are white and gray, associated with the nodes of the sympathetic trunk;

visceral nerves, consisting of sympathetic and sensory fibers and heading to the organs, where they end in nerve endings.

THE SYMPATHETIC TRUNK, paired, is located on both sides of the spine in the form of a chain of first-order nodes. In the longitudinal direction, the nodes are connected to each other by internodal branches. In the lumbar and sacral regions there are also transverse commissures that connect the nodes of the right and left sides. The sympathetic trunk extends from the base of the skull to the coccyx, where the right and left trunks are connected by one unpaired coccygeal node. Topographically, the sympathetic trunk is divided into 4 sections: cervical, thoracic, lumbar and sacral.

The nodes of the sympathetic trunk are connected to the spinal nerves by white and gray communicating branches.

White connecting branches consist of preganglionic sympathetic fibers, which are axons of the cells of the intermediolateral nuclei of the lateral horns of the spinal cord. They are separated from the spinal nerve trunk and enter the nearest nodes of the sympathetic trunk, where part of the preganglionic sympathetic fibers are interrupted. The other part passes through the node in transit and through the internodal branches reaches more distant nodes of the sympathetic trunk or passes to nodes of the second order.

Sensitive fibers, the dendrites of the cells of the spinal ganglia, also pass through the white connecting branches.

The white connecting branches go only to the thoracic and upper lumbar nodes. Preganglionic fibers enter the cervical nodes from below from the thoracic nodes of the sympathetic trunk through the internodal branches, and into the lower lumbar and sacral nodes - from the upper lumbar nodes also through the internodal branches.

From all nodes of the sympathetic trunk, part of the postganglionic fibers joins the spinal nerves - gray connecting branches and as part of the spinal nerves, sympathetic fibers are directed to the skin and skeletal muscles in order to ensure the regulation of its trophism and maintain tone - this somatic part sympathetic nervous system.

In addition to the gray connecting branches, visceral branches depart from the nodes of the sympathetic trunk to innervate the internal organs - visceral part sympathetic nervous system. It consists of: postganglionic fibers (cell processes of the sympathetic trunk), preganglionic fibers that passed through the first order nodes without interruption, as well as sensory fibers (cell processes of the spinal nodes).

Cervical region The sympathetic trunk most often consists of three nodes: upper, middle and lower.

U p p e r cervical node lies in front of the transverse processes of the II-III cervical vertebrae. The following branches depart from it, which often form plexuses along the walls of blood vessels:

Internal carotid plexus(along the walls of the artery of the same name ) . The deep petrosal nerve departs from the internal carotid plexus to innervate the glands of the mucous membrane of the nasal cavity and palate. A continuation of this plexus is the plexus of the ophthalmic artery (for the innervation of the lacrimal gland and the muscle that dilates the pupil ) and plexus of cerebral arteries.

External carotid plexus. Due to secondary plexuses along the branches of the external carotid artery, the salivary glands are innervated.

Laryngopharyngeal branches.

Superior cervical cardiac nerve

MIDDLE cervical node located at the level of the VI cervical vertebra. Branches extend from it:

Branches to the inferior thyroid artery.

Middle cervical cardiac nerve, entering the cardiac plexus.

LOWER NECK JOINT is located at the level of the head of the 1st rib and often merges with the 1st thoracic node, forming the cervicothoracic node (stellate). Branches extend from it:

Inferior cervical cardiac nerve, entering the cardiac plexus.

Branches to the trachea, bronchi, esophagus, which, together with the branches of the vagus nerve, form plexuses.

Thoracic region The sympathetic trunk consists of 10-12 nodes. The following branches depart from them:

Visceral branches depart from the upper 5-6 nodes to innervate the organs of the thoracic cavity, namely:

Thoracic cardiac nerves.

Branches to the aorta, forming the thoracic aortic plexus.

Branches to the trachea and bronchi, participating together with the branches of the vagus nerve in the formation of the pulmonary plexus.

Branches to the esophagus.

5. Branches extend from V-IX thoracic nodes, forming great splanchnic nerve.

6. From X-XI thoracic nodes - small splanchnic nerve.

The splanchnic nerves pass into the abdominal cavity and enter the celiac plexus.

Lumbar The sympathetic trunk consists of 4-5 nodes.

The visceral nerves depart from them - splanchnic lumbar nerves. The upper ones enter the celiac plexus, the lower ones enter the aortic and inferior mesenteric plexuses.

Sacral section The sympathetic trunk is represented, as a rule, by four sacral nodes and one unpaired coccygeal node.

They are moving away from them splanchnic nerves, entering the superior and inferior hypogastric plexuses.

PRESPINAL NODES AND AUTONOMIC PLEXUS

Prevertebral nodes (nodes of the second order) are part of the autonomic plexuses and are located in front of the spinal column. On the motor neurons of these nodes, preganglionic fibers end, passing through the nodes of the sympathetic trunk without interruption.

Autonomic plexuses are located mainly around blood vessels, or directly near organs. Topographically, the autonomic plexuses of the head and neck, chest, abdominal and pelvic cavities are distinguished. In the head and neck area, the sympathetic plexuses are located mainly around the vessels.

In the chest cavity, the sympathetic plexuses are located around the descending aorta, in the region of the heart, at the hilum of the lung and along the bronchi, around the esophagus.

The most significant in the chest cavity is cardiac plexus.

In the abdominal cavity, sympathetic plexuses surround the abdominal aorta and its branches. Among them, the largest plexus is the celiac plexus (“brain of the abdominal cavity”).

Celiac plexus(solar) surrounds the beginning of the celiac trunk and the superior mesenteric artery. The plexus is bounded above by the diaphragm, on the sides by the adrenal glands, and below it reaches the renal arteries. The following take part in the formation of this plexus: nodes(second order nodes):

Right and left celiac ganglia semi-lunar shape.

Unpaired superior mesenteric ganglion.

Right and left aortorenal nodes, located at the point of origin of the renal arteries from the aorta.

These nodes receive preganglionic sympathetic fibers, which are switched here, as well as postganglionic sympathetic and parasympathetic and sensory fibers passing through them.

Participate in the formation of the celiac plexus nerves:

Greater and lesser splanchnic nerves, extending from the thoracic nodes of the sympathetic trunk.

Lumbar splanchnic nerves - from the upper lumbar nodes of the sympathetic trunk.

Branches of the phrenic nerve.

Branches of the vagus nerve, consisting predominantly of preganglionic parasympathetic and sensory fibers.

A continuation of the celiac plexus are secondary paired and unpaired plexuses along the walls of the visceral and parietal branches of the abdominal aorta.

The second most important element in the innervation of the abdominal organs is abdominal aortic plexus, which is a continuation of the celiac plexus.

Derived from the aortic plexus inferior mesenteric plexus, entwining the artery of the same name and its branches. Here is located

quite a large node. The fibers of the inferior mesenteric plexus reach the sigmoid, descending and part of the transverse colon. The continuation of this plexus into the pelvic cavity is the superior rectal plexus, which accompanies the artery of the same name.

The continuation of the abdominal aortic plexus downwards are the plexuses of the iliac arteries and arteries of the lower limb, as well as unpaired superior hypogastric plexus, which at the level of the promontory is divided into the right and left hypogastric nerves, forming the inferior hypogastric plexus in the pelvic cavity.

In education inferior hypogastric plexus autonomic nodes of the second order (sympathetic) and third order (periorgan, parasympathetic), as well as nerves and plexuses participate:

1. Sternal sacral nerves- from the sacral section of the sympathetic trunk.

2.Branches of the inferior mesenteric plexus.

3. Splanchnic pelvic nerves, consisting of preganglionic parasympathetic fibers - processes of the cells of the intermediate-lateral nuclei of the sacral spinal cord and sensory fibers from the sacral spinal ganglia.

PARASYMPATHETIC DIVISION OF THE AUTONOMIC NERVOUS SYSTEM

The parasympathetic nervous system consists of central and peripheral divisions.

Central department includes nuclei located in the brain stem, namely in the midbrain (mesencephalic region), pons and medulla oblongata (bulbar region), as well as in the spinal cord (sacral region).

Peripheral department presented by:

preganglionic parasympathetic fibers passing through the III, VII, IX, X pairs of cranial nerves, as well as the splanchnic pelvic nerves.

nodes of the third order;

postganglionic fibers that end on smooth muscle and glandular cells.

Parasympathetic part of the oculomotor nerve (IIIpair) represented by the accessory nucleus located in the midbrain. Preganglionic fibers go as part of the oculomotor nerve, approach the ciliary ganglion, located in the orbit, the postganglionic fibers are interrupted there and penetrate into the eyeball to the muscle that constricts the pupil, ensuring the reaction of the pupil to light, as well as to the ciliary muscle, which affects the change in curvature of the lens.

Parasympathetic part of the interfacial nerve (VIIpair) represented by the superior salivary nucleus, which is located in the pons. The axons of the cells of this nucleus pass as part of the intermediate nerve, which joins the facial nerve. In the facial canal, parasympathetic fibers are separated from the facial nerve in two portions. One portion is isolated in the form of a large petrosal nerve, the other in the form of a tympanic chord.

Greater petrosal nerve connects with the deep petrosal nerve (sympathetic) and forms the nerve of the pterygoid canal. As part of this nerve, preganglionic parasympathetic fibers reach the pterygopalatine ganglion and end on its cells.

Postganglionic fibers from the node innervate the glands of the mucous membrane of the palate and nose. A minority of postganglionic fibers reach the lacrimal gland.

Another portion of preganglionic parasympathetic fibers in the composition drum string joins the lingual nerve (from the third branch of the trigeminal nerve) and, as part of its branch, approaches the submandibular node, where they are interrupted. The axons of ganglion cells (postganglionic fibers) innervate the submandibular and sublingual salivary glands.

Parasympathetic part of the glossopharyngeal nerve (IXpair) represented by the inferior salivary nucleus located in the medulla oblongata. Preganglionic fibers emerge as part of the glossopharyngeal nerve, and then its branches - tympanic nerve, which penetrates the tympanic cavity and forms the tympanic plexus, which innervates the glands of the mucous membrane of the tympanic cavity. Its continuation is lesser petrosal nerve, which exits the cranial cavity and enters the auricular ganglion, where the preganglionic fibers are interrupted. Postganglionic fibers are directed to the parotid salivary gland.

Parasympathetic part of the vagus nerve (Xpair) represented by the dorsal nucleus. Preganglionic fibers from this nucleus, as part of the vagus nerve and its branches, reach the parasympathetic nodes (III

order), which are located in the wall of internal organs (esophageal, pulmonary, cardiac, gastric, intestinal, pancreas, etc. or at the gates of organs (liver, kidneys, spleen). The vagus nerve innervates the smooth muscles and glands of the internal organs of the neck, thoracic and abdominal cavity to the sigmoid colon.

Sacral division of the parasympathetic part of the autonomic nervous system represented by the intermediate-lateral nuclei of the II-IV sacral segments of the spinal cord. Their axons (preganglionic fibers) leave the spinal cord as part of the anterior roots, and then the anterior branches of the spinal nerves. They are separated from them in the form pelvic splanchnic nerves and enter the inferior hypogastric plexus to innervate the pelvic organs. Some preganglionic fibers have an ascending direction to innervate the sigmoid colon.

The autonomic nervous system plays no less important role in the functioning of the human body than the central one. Its various departments control the acceleration of metabolism, the renewal of energy reserves, the control of blood circulation, respiration, digestion and more. For a personal trainer, knowledge of what the human autonomic nervous system is needed for, what it consists of, and how it works is a necessary condition for his professional development.

The autonomic nervous system (also known as autonomic, visceral and ganglionic) is part of the entire nervous system of the human body and is a kind of aggregator of central and peripheral nervous formations, which are responsible for regulating the functional activity of the body, necessary for the appropriate reaction of its systems to various stimuli. It controls the functioning of internal organs, endocrine and exocrine glands, as well as blood and lymphatic vessels. Plays an important role in maintaining homeostasis and the adequate course of the body’s adaptation processes.

The work of the autonomic nervous system is in fact not controlled by humans. This suggests that a person is not able to influence the functioning of the heart or digestive tract through any effort. However, it is still possible to achieve conscious influence on many parameters and processes that are controlled by the ANS, in the process of undergoing a complex of physiological, preventive and therapeutic procedures using computer technology.

Structure of the autonomic nervous system

Both in structure and function, the autonomic nervous system is divided into sympathetic, parasympathetic and metasympathetic. The sympathetic and parasympathetic centers control the cerebral cortex and hypothalamic centers. Both the first and second sections have a central and peripheral part. The central part is formed from the cell bodies of neurons that are found in the brain and spinal cord. Such formations of nerve cells are called vegetative nuclei. Fibers that arise from the nuclei, autonomic ganglia that lie outside the central nervous system, and nerve plexuses within the walls of the internal organs form the peripheral part of the autonomic nervous system.

The sympathetic nuclei are located in the spinal cord. The nerve fibers that branch from it end outside the spinal cord in the sympathetic ganglia, and from them the nerve fibers that go to the organs originate.
Parasympathetic nuclei are located in the midbrain and medulla oblongata, as well as in the sacral part of the spinal cord. Nerve fibers of the nuclei of the medulla oblongata are present in the vagus nerves. The nuclei of the sacral part conduct nerve fibers to the intestines and excretory organs.

The metasympathetic nervous system consists of nerve plexuses and small ganglia within the walls of the digestive tract, as well as the bladder, heart and other organs.

Structure of the autonomic nervous system: 1- Brain; 2- Nerve fibers to the meninges; 3- Pituitary gland; 4- Cerebellum; 5- Medulla oblongata; 6, 7- Parasympathetic fibers of the ocular motor and facial nerves; 8- Star knot; 9- Border pillar; 10- Spinal nerves; 11- Eyes; 12- Salivary glands; 13- Blood vessels; 14- Thyroid gland; 15- Heart; 16- Lungs; 17- Stomach; 18- Liver; 19- Pancreas; 20- Adrenal glands; 21- Small intestine; 22- Large intestine; 23- Kidneys; 24- Bladder; 25- Genital organs.

I- Cervical region; II- Thoracic department; III- Lumbar; IV- Sacrum; V- Coccyx; VI- Vagus nerve; VII- Solar plexus; VIII- Superior mesenteric node; IX- Inferior mesenteric node; X- Parasympathetic nodes of the hypogastric plexus.

The sympathetic nervous system speeds up metabolism, increases stimulation of many tissues, and activates the body's strength for physical activity. The parasympathetic nervous system helps regenerate wasted energy reserves and also controls the functioning of the body during sleep. The autonomic nervous system controls the organs of circulation, respiration, digestion, excretion, reproduction, and among other things, metabolism and growth processes. By and large, the efferent section of the ANS controls the nervous regulation of the work of all organs and tissues with the exception of skeletal muscles, which are controlled by the somatic nervous system.

Morphology of the autonomic nervous system

The identification of the ANS is associated with the characteristic features of its structure. These features usually include: localization of the vegetative nuclei in the central nervous system; accumulation of bodies of effector neurons in the form of nodes within the autonomic plexuses; two-neuronality of the nerve pathway from the autonomic nucleus in the central nervous system to the target organ.

Structure of the spinal cord: 1- Spine; 2- Spinal cord; 3- Articular process; 4- Transverse process; 5- Spinous process; 6- Place of attachment of the rib; 7- Vertebral body; 8- Intervertebral disc; 9- Spinal nerve; 10- Central canal of the spinal cord; 11- Vertebral nerve ganglion; 12- Soft shell; 13- Arachnoid membrane; 14- Hard shell.

The fibers of the autonomic nervous system do not branch in segments, as, for example, in the somatic nervous system, but from three localized areas of the spinal cord remote from each other - the cranial sternolumbar and sacral. As for the previously mentioned sections of the autonomic nervous system, in its sympathetic part the processes of spinal neurons are short, and the ganglion ones are long. In the parasympathetic system the opposite is true. The processes of spinal neurons are longer, and those of ganglion neurons are shorter. It is worth noting here that sympathetic fibers innervate all organs without exception, while the local innervation of parasympathetic fibers is largely limited.

Divisions of the autonomic nervous system

Based on topographical characteristics, the ANS is divided into central and peripheral sections.

Central department. It is represented by the parasympathetic nuclei of the 3rd, 7th, 9th and 10th pairs of cranial nerves running in the brain stem (craniobulbar region) and nuclei located in the gray matter of the three sacral segments (sacral region). The sympathetic nuclei are located in the lateral horns of the thoracolumbar spinal cord.
Peripheral department. Represented by autonomic nerves, branches and nerve fibers emerging from the brain and spinal cord. This also includes the autonomic plexuses, nodes of the autonomic plexuses, the sympathetic trunk (right and left) with its nodes, internodal and connecting branches and sympathetic nerves. As well as the terminal nodes of the parasympathetic part of the autonomic nervous system.

Functions of the autonomic nervous system

The main function of the autonomic nervous system is to ensure an adequate adaptive response of the body to various stimuli. The ANS ensures control of the constancy of the internal environment, and also takes part in multiple responses that occur under the control of the brain, and these reactions can be both physiological and mental in nature. As for the sympathetic nervous system, it is activated when stress reactions occur. It is characterized by a global effect on the body, with sympathetic fibers innervating most organs. It is also known that parasympathetic stimulation of some organs leads to an inhibitory reaction, and of other organs, on the contrary, to an exciting one. In the vast majority of cases, the action of the sympathetic and parasympathetic nervous systems is opposite.

The autonomic centers of the sympathetic department are located in the thoracic and lumbar parts of the spinal cord, the centers of the parasympathetic department are located in the brain stem (eyes, glands and organs innervated by the vagus nerve), as well as in the sacral part of the spinal cord (bladder, lower colon and genitals). Preganglionic fibers of both the first and second sections of the autonomic nervous system run from the centers to the ganglia, where they end on postganglionic neurons.

Preganglionic sympathetic neurons originate in the spinal cord and end either in the paravertebral ganglion chain (in the cervical or abdominal ganglion) or in the so-called terminal ganglia. The transmission of stimulus from preganglionic neurons to postganglionic neurons is cholinergic, that is, mediated by the release of the neurotransmitter acetylcholine. Stimulation by postganglionic sympathetic fibers of all effector organs, with the exception of the sweat glands, is adrenergic, that is, mediated by the release of norepinephrine.

Now let's look at the effect of the sympathetic and parasympathetic departments on specific internal organs.

Effect of the sympathetic department: on the pupils - has a dilating effect. On arteries – has a dilating effect. On the salivary glands - inhibits salivation. On the heart - increases the frequency and strength of its contractions. It has a relaxing effect on the bladder. On the intestines - inhibits peristalsis and enzyme production. On the bronchi and breathing - expands the lungs, improves their ventilation.
Effect of the parasympathetic department: on the pupils - has a constricting effect. On the arteries - in most organs it has no effect, it causes dilation of the arteries of the genitals and brain, as well as a narrowing of the coronary arteries and arteries of the lungs. On the salivary glands – stimulates salivation. On the heart - reduces the strength and frequency of its contractions. On the bladder – promotes its contraction. On the intestines - enhances peristalsis and stimulates the production of digestive enzymes. On the bronchi and breathing - narrows the bronchi, reduces ventilation of the lungs.

Basic reflexes often occur within a specific organ (for example, in the stomach), but more complex (complex) reflexes pass through the controlling autonomic centers in the central nervous system, mainly in the spinal cord. These centers are controlled by the hypothalamus, whose activity is associated with the autonomic nervous system. The cerebral cortex is the most highly organized nerve center that connects the ANS with other systems.

Conclusion

The autonomic nervous system, through its subordinate structures, activates a number of simple and complex reflexes. Some fibers (afferents) carry stimuli from the skin and pain receptors in organs such as the lungs, gastrointestinal tract, gallbladder, vascular system and genitals. Other fibers (efferent) conduct a reflex response to afferent signals, implementing smooth muscle contractions in organs such as the eyes, lungs, digestive tract, gall bladder, heart and glands. Knowledge about the autonomic nervous system, as one of the elements of the integral nervous system of the human body, is an integral part of the theoretical minimum that a personal trainer should have.

Under The term sympathetic nervous system refers to specific segment (department) autonomic nervous system. Its structure is characterized by some segmentation. This section is classified as trophic. Its tasks are to supply the organs with nutrients,, if necessary, increase the rate of oxidative processes, improve breathing, and create conditions for the supply of more oxygen to the muscles. In addition, an important task is to speed up the work of the heart if necessary.

Lecture for doctors "Sympathetic nervous system". The autonomic nervous system is divided into sympathetic and parasympathetic parts. The sympathetic part of the nervous system includes:

lateral intermediate substance in the lateral columns of the spinal cord;
sympathetic nerve fibers and nerves going from the cells of the lateral intermediate substance to the nodes of the sympathetic and autonomic plexuses of the abdominal pelvic cavity;
sympathetic trunk, communicating nerves connecting the spinal nerves to the sympathetic trunk;
nodes of the autonomic nerve plexuses;
nerves running from these plexuses to the organs;
sympathetic fibers.

AUTONOMIC NERVOUS SYSTEM

The autonomic (autonomic) nervous system regulates all internal processes of the body: the functions of internal organs and systems, glands, blood and lymph vessels, smooth and partially striated muscles, sensory organs (Fig. 6.1). It ensures homeostasis of the body, i.e. the relative dynamic constancy of the internal environment and the stability of its basic physiological functions (blood circulation, respiration, digestion, thermoregulation, metabolism, excretion, reproduction, etc.). In addition, the autonomic nervous system performs an adaptation-trophic function - regulation of metabolism in relation to environmental conditions.

The term "autonomic nervous system" reflects the control of involuntary functions of the body. The autonomic nervous system is dependent on the higher centers of the nervous system. There is a close anatomical and functional relationship between the autonomic and somatic parts of the nervous system. Autonomic nerve conductors pass through the cranial and spinal nerves. The main morphological unit of the autonomic nervous system, like the somatic one, is the neuron, and the main functional unit is the reflex arc. The autonomic nervous system has a central (cells and fibers located in the brain and spinal cord) and peripheral (all its other formations) sections. There are also sympathetic and parasympathetic parts. Their main difference lies in the characteristics of functional innervation and is determined by their attitude to drugs that affect the autonomic nervous system. The sympathetic part is excited by adrenaline, and the parasympathetic part by acetylcholine. Ergotamine has an inhibitory effect on the sympathetic part, and atropine has an inhibitory effect on the parasympathetic part.

6.1. Sympathetic division of the autonomic nervous system

The central formations are located in the cerebral cortex, hypothalamic nuclei, brain stem, reticular formation, and also in the spinal cord (in the lateral horns). The cortical representation has not been sufficiently elucidated. From the cells of the lateral horns of the spinal cord at levels from C VIII to L V, the peripheral formations of the sympathetic department begin. The axons of these cells pass as part of the anterior roots and, having separated from them, form a connecting branch that approaches the nodes of the sympathetic trunk. This is where some of the fibers end. From the cells of the nodes of the sympathetic trunk, the axons of the second neurons begin, which again approach the spinal nerves and end in the corresponding segments. The fibers that pass through the nodes of the sympathetic trunk, without interruption, approach the intermediate nodes located between the innervated organ and the spinal cord. From the intermediate nodes, the axons of the second neurons begin, heading to the innervated organs.

Rice. 6.1.

1 - cortex of the frontal lobe of the cerebrum; 2 - hypothalamus; 3 - ciliary node; 4 - pterygopalatine node; 5 - submandibular and sublingual nodes; 6 - ear node; 7 - superior cervical sympathetic node; 8 - great splanchnic nerve; 9 - internal node; 10 - celiac plexus; 11 - celiac nodes; 12 - small splanchnic nerve; 12a - lower splanchnic nerve; 13 - superior mesenteric plexus; 14 - inferior mesenteric plexus; 15 - aortic plexus; 16 - sympathetic fibers to the anterior branches of the lumbar and sacral nerves for the vessels of the legs; 17 - pelvic nerve; 18 - hypogastric plexus; 19 - ciliary muscle; 20 - sphincter of the pupil; 21 - pupil dilator; 22 - lacrimal gland; 23 - glands of the mucous membrane of the nasal cavity; 24 - submandibular gland; 25 - sublingual gland; 26 - parotid gland; 27 - heart; 28 - thyroid gland; 29 - larynx; 30 - muscles of the trachea and bronchi; 31 - lung; 32 - stomach; 33 - liver; 34 - pancreas; 35 - adrenal gland; 36 - spleen; 37 - kidney; 38 - large intestine; 39 - small intestine; 40 - detrusor of the bladder (muscle that pushes urine); 41 - sphincter of the bladder; 42 - gonads; 43 - genitals; III, XIII, IX, X - cranial nerves

The sympathetic trunk is located along the lateral surface of the spine and includes 24 pairs of sympathetic nodes: 3 cervical, 12 thoracic, 5 lumbar, 4 sacral. From the axons of the cells of the upper cervical sympathetic node, the sympathetic plexus of the carotid artery is formed, from the lower - the upper cardiac nerve, which forms the sympathetic plexus in the heart. The thoracic nodes innervate the aorta, lungs, bronchi, and abdominal organs, and the lumbar nodes innervate the pelvic organs.

6.2. Parasympathetic division of the autonomic nervous system

Its formations begin from the cerebral cortex, although the cortical representation, as well as the sympathetic part, has not been sufficiently elucidated (mainly the limbic-reticular complex). There are mesencephalic and bulbar sections in the brain and sacral sections in the spinal cord. The mesencephalic section includes the nuclei of the cranial nerves: III pair - accessory nucleus of Yakubovich (paired, parvocellular), innervating the muscle that constricts the pupil; Perlia's nucleus (unpaired parvocellular) innervates the ciliary muscle involved in accommodation. The bulbar section consists of the superior and inferior salivary nuclei (VII and IX pairs); X pair - vegetative nucleus, innervating the heart, bronchi, gastrointestinal tract,

its digestive glands and other internal organs. The sacral section is represented by cells in segments S II -S IV, the axons of which form the pelvic nerve, innervating the genitourinary organs and rectum (Fig. 6.1).

All organs are under the influence of both the sympathetic and parasympathetic parts of the autonomic nervous system, with the exception of blood vessels, sweat glands and the adrenal medulla, which have only sympathetic innervation. The parasympathetic department is more ancient. As a result of its activity, stable states of organs and conditions for the creation of reserves of energy substrates are created. The sympathetic part modifies these states (i.e., the functional abilities of the organs) in relation to the function performed. Both parts function in close cooperation. Under certain conditions, functional predominance of one part over the other is possible. If the tone of the parasympathetic part predominates, a state of parasympathotonia develops, and the sympathetic part - sympathotonia. Parasympathotonia is characteristic of the sleep state, sympathotonia is characteristic of affective states (fear, anger, etc.).

In clinical conditions, conditions are possible in which the activity of individual organs or systems of the body is disrupted as a result of the predominance of the tone of one of the parts of the autonomic nervous system. Parasympathotonic manifestations accompany bronchial asthma, urticaria, Quincke's edema, vasomotor rhinitis, motion sickness; sympathotonic - vascular spasm in the form of Raynaud's syndrome, migraine, transient form of hypertension, vascular crises with hypothalamic syndrome, ganglion lesions, panic attacks. The integration of autonomic and somatic functions is carried out by the cerebral cortex, hypothalamus and reticular formation.

6.3. Limbic-reticular complex

All activities of the autonomic nervous system are controlled and regulated by the cortical parts of the nervous system (frontal cortex, parahippocampal and cingulate gyri). The limbic system is the center of emotion regulation and the neural substrate of long-term memory. The rhythm of sleep and wakefulness is also regulated by the limbic system.

Rice. 6.2. Limbic system. 1 - corpus callosum; 2 - vault; 3 - belt; 4 - posterior thalamus; 5 - isthmus of the cingulate gyrus; 6 - III ventricle; 7 - mastoid body; 8 - bridge; 9 - lower longitudinal beam; 10 - border; 11 - hippocampal gyrus; 12 - hook; 13 - orbital surface of the frontal pole; 14 - hook-shaped beam; 15 - transverse connection of the amygdala; 16 - anterior commissure; 17 - anterior thalamus; 18 - cingulate gyrus

The limbic system (Fig. 6.2) is understood as a number of closely interconnected cortical and subcortical structures that have common development and functions. It also includes the formations of the olfactory pathways located at the base of the brain, the septum pellucidum, the vaulted gyrus, the cortex of the posterior orbital surface of the frontal lobe, the hippocampus, and the dentate gyrus. The subcortical structures of the limbic system include the caudate nucleus, putamen, amygdala, anterior tubercle of the thalamus, hypothalamus, frenulus nucleus. The limbic system includes a complex interweaving of ascending and descending pathways, closely associated with the reticular formation.

Irritation of the limbic system leads to the mobilization of both sympathetic and parasympathetic mechanisms, which has corresponding autonomic manifestations. A pronounced autonomic effect occurs when the anterior parts of the limbic system are irritated, in particular the orbital cortex, amygdala and cingulate gyrus. In this case, changes in salivation, respiratory rate, increased intestinal motility, urination, defecation, etc. appear.

Of particular importance in the functioning of the autonomic nervous system is the hypothalamus, which regulates the functions of the sympathetic and parasympathetic systems. In addition, the hypothalamus realizes the interaction of nervous and endocrine, the integration of somatic and autonomic activity. The hypothalamus has specific and nonspecific nuclei. Specific nuclei produce hormones (vasopressin, oxytocin) and releasing factors that regulate the secretion of hormones by the anterior pituitary gland.

Sympathetic fibers innervating the face, head and neck begin from cells located in the lateral horns of the spinal cord (C VIII -Th III). Most of the fibers are interrupted in the superior cervical sympathetic ganglion, and a smaller part is directed to the external and internal carotid arteries and forms periarterial sympathetic plexuses on them. They are joined by postganglionic fibers coming from the middle and lower cervical sympathetic nodes. In small nodules (cellular accumulations) located in the periarterial plexuses of the branches of the external carotid artery, fibers that are not interrupted in the nodes of the sympathetic trunk end. The remaining fibers are interrupted in the facial ganglia: ciliary, pterygopalatine, sublingual, submandibular and auricular. Postganglionic fibers from these nodes, as well as fibers from the cells of the superior and other cervical sympathetic nodes, go to the tissues of the face and head, partly as part of the cranial nerves (Fig. 6.3).

Afferent sympathetic fibers from the head and neck are directed to the periarterial plexuses of the branches of the common carotid artery, pass through the cervical nodes of the sympathetic trunk, partially contacting their cells, and through the connecting branches they approach the spinal nodes, closing the reflex arc.

Parasympathetic fibers are formed by the axons of the stem parasympathetic nuclei and are directed mainly to the five autonomic ganglia of the face, where they are interrupted. A minority of the fibers are directed to the parasympathetic clusters of cells of the periarterial plexuses, where they are also interrupted, and the postganglionic fibers go as part of the cranial nerves or periarterial plexuses. The parasympathetic part also contains afferent fibers that run in the vagus nerve system and are directed to the sensory nuclei of the brain stem. The anterior and middle sections of the hypothalamic region, through sympathetic and parasympathetic conductors, influence the function of predominantly ipsilateral salivary glands.

6.5. Autonomic innervation of the eye

Sympathetic innervation. Sympathetic neurons are located in the lateral horns of segments C VIII - Th III of the spinal cord (centrun ciliospinale).

Rice. 6.3.

1 - posterior central nucleus of the oculomotor nerve; 2 - accessory nucleus of the oculomotor nerve (Yakubovich-Edinger-Westphal nucleus); 3 - oculomotor nerve; 4 - nasociliary branch from the optic nerve; 5 - ciliary node; 6 - short ciliary nerves; 7 - sphincter of the pupil; 8 - pupil dilator; 9 - ciliary muscle; 10 - internal carotid artery; 11 - carotid plexus; 12 - deep petrosal nerve; 13 - upper salivary nucleus; 14 - intermediate nerve; 15 - elbow assembly; 16 - greater petrosal nerve; 17 - pterygopalatine node; 18 - maxillary nerve (II branch of the trigeminal nerve); 19 - zygomatic nerve; 20 - lacrimal gland; 21 - mucous membranes of the nose and palate; 22 - genicular tympanic nerve; 23 - auriculotemporal nerve; 24 - middle meningeal artery; 25 - parotid gland; 26 - ear node; 27 - lesser petrosal nerve; 28 - tympanic plexus; 29 - auditory tube; 30 - single track; 31 - lower salivary nucleus; 32 - drum string; 33 - tympanic nerve; 34 - lingual nerve (from the mandibular nerve - III branch of the trigeminal nerve); 35 - taste fibers to the anterior 2/3 of the tongue; 36 - sublingual gland; 37 - submandibular gland; 38 - submandibular node; 39 - facial artery; 40 - superior cervical sympathetic node; 41 - cells of the lateral horn ThI-ThII; 42 - lower node of the glossopharyngeal nerve; 43 - sympathetic fibers to the plexuses of the internal carotid and middle meningeal arteries; 44 - innervation of the face and scalp. III, VII, IX - cranial nerves. Parasympathetic fibers are indicated in green, sympathetic in red, and sensory in blue.

The processes of these neurons, forming preganglionic fibers, leave the spinal cord along with the anterior roots, enter the sympathetic trunk as part of the white connecting branches and, without interruption, pass through the overlying nodes, ending at the cells of the upper cervical sympathetic plexus. Postganglionic fibers of this node accompany the internal carotid artery, weaving around its wall, penetrate into the cranial cavity, where they connect with the first branch of the trigeminal nerve, penetrate into the orbital cavity and end at the muscle that dilates the pupil. (m. dilatator pupillae).

Sympathetic fibers also innervate other structures of the eye: the tarsal muscles that expand the palpebral fissure, the orbital muscle of the eye, as well as some structures of the face - the sweat glands of the face, smooth muscles of the face and blood vessels.

Parasympathetic innervation. The preganglionic parasympathetic neuron lies in the accessory nucleus of the oculomotor nerve. As part of the latter, it leaves the brain stem and reaches the ciliary ganglion (ganglion ciliare), where it switches to postganglionic cells. From there, part of the fibers is sent to the muscle that constricts the pupil (m. sphincter pupillae), and the other part is involved in providing accommodation.

Disturbance of the autonomic innervation of the eye. Damage to the sympathetic formations causes Bernard-Horner syndrome (Fig. 6.4) with constriction of the pupil (miosis), narrowing of the palpebral fissure (ptosis), and retraction of the eyeball (enophthalmos). The development of homolateral anhidrosis, conjunctival hyperemia, and depigmentation of the iris are also possible.

The development of Bernard-Horner syndrome is possible when the lesion is localized at different levels - involving the posterior longitudinal fasciculus, pathways to the muscle that dilates the pupil. The congenital variant of the syndrome is more often associated with birth trauma with damage to the brachial plexus.

When sympathetic fibers are irritated, a syndrome occurs that is the opposite of Bernard-Horner syndrome (Pourfour du Petit) - dilatation of the palpebral fissure and pupil (mydriasis), exophthalmos.

6.6. Autonomic innervation of the bladder

Regulation of bladder activity is carried out by the sympathetic and parasympathetic parts of the autonomic nervous system (Fig. 6.5) and includes urinary retention and bladder emptying. Normally, retention mechanisms are more activated, which

Rice. 6.4. Right-sided Bernard-Horner syndrome. Ptosis, miosis, enophthalmos

is carried out as a result of activation of sympathetic innervation and blockade of the parasympathetic signal at the level of segments L I - L II of the spinal cord, while the activity of the detrusor is suppressed and the tone of the muscles of the internal sphincter of the bladder increases.

Regulation of the act of urination occurs when activated

the parasympathetic center at the level of S II -S IV and the micturition center in the pons (Fig. 6.6). Descending efferent signals send signals that relax the external sphincter, suppress sympathetic activity, remove the block of conduction along parasympathetic fibers, and stimulate the parasympathetic center. The consequence of this is contraction of the detrusor and relaxation of the sphincters. This mechanism is under the control of the cerebral cortex; the reticular formation, the limbic system, and the frontal lobes of the cerebral hemispheres take part in the regulation.

Voluntary cessation of urination occurs when a command is received from the cerebral cortex to the micturition centers in the brain stem and sacral spinal cord, which leads to contraction of the external and internal sphincters of the pelvic floor muscles and periurethral striated muscles.

Damage to the parasympathetic centers of the sacral region and the autonomic nerves emanating from it is accompanied by the development of urinary retention. It can also occur when the spinal cord is damaged (trauma, tumor, etc.) at a level above the sympathetic centers (Th XI -L II). Partial damage to the spinal cord above the level of the autonomic centers can lead to the development of an imperative urge to urinate. When the spinal sympathetic center (Th XI - L II) is damaged, true urinary incontinence occurs.

Research methodology. There are numerous clinical and laboratory methods for studying the autonomic nervous system; their choice is determined by the task and conditions of the study. However, in all cases it is necessary to take into account the initial autonomic tone and the level of fluctuations relative to the background value. The higher the initial level, the lower the response will be during functional tests. In some cases, even a paradoxical reaction is possible. Ray study

Rice. 6.5.

1 - cerebral cortex; 2 - fibers that provide voluntary control over bladder emptying; 3 - fibers of pain and temperature sensitivity; 4 - cross section of the spinal cord (Th IX -L II for sensory fibers, Th XI -L II for motor fibers); 5 - sympathetic chain (Th XI -L II); 6 - sympathetic chain (Th IX -L II); 7 - cross section of the spinal cord (segments S II -S IV); 8 - sacral (unpaired) node; 9 - genital plexus; 10 - pelvic splanchnic nerves;

11 - hypogastric nerve; 12 - lower hypogastric plexus; 13 - genital nerve; 14 - external sphincter of the bladder; 15 - bladder detrusor; 16 - internal sphincter of the bladder

Rice. 6.6.

It is better to do it in the morning on an empty stomach or 2 hours after meals, at the same time, at least 3 times. The minimum value of the received data is taken as the initial value.

The main clinical manifestations of the predominance of the sympathetic and parasympathetic systems are presented in table. 6.1.

To assess autonomic tone, it is possible to conduct tests with exposure to pharmacological agents or physical factors. Solutions of adrenaline, insulin, mezaton, pilocarpine, atropine, histamine, etc. are used as pharmacological agents.

Cold test. With the patient lying down, heart rate is calculated and blood pressure is measured. After this, the hand of the other hand is immersed in cold water (4 °C) for 1 minute, then the hand is removed from the water and blood pressure and pulse are recorded every minute until it returns to the original level. Normally this happens within 2-3 minutes. When blood pressure increases by more than 20 mm Hg. Art. the reaction is considered pronounced sympathetic, less than 10 mm Hg. Art. - moderate sympathetic, and with a decrease in blood pressure - parasympathetic.

Oculocardiac reflex (Danyini-Aschner). When pressing on the eyeballs in healthy people, the heart rate slows down by 6-12 per minute. If the heart rate decreases by 12-16 per minute, this is regarded as a sharp increase in the tone of the parasympathetic part. The absence of a decrease or an increase in heart rate by 2-4 per minute indicates an increase in the excitability of the sympathetic department.

Solar reflex. The patient lies on his back, and the examiner presses his hand on the upper abdomen until a pulsation of the abdominal aorta is felt. After 20-30 s, the heart rate slows down in healthy people by 4-12 per minute. Changes in cardiac activity are assessed in the same way as when inducing the oculocardiac reflex.

Orthoclinostatic reflex. The patient's heart rate is calculated while lying on his back, and then he is asked to quickly stand up (orthostatic test). When moving from a horizontal to a vertical position, heart rate increases by 12 per minute with an increase in blood pressure by 20 mmHg. Art. When the patient moves to a horizontal position, pulse and blood pressure return to their original values within 3 minutes (clinostatic test). The degree of pulse acceleration during an orthostatic test is an indicator of the excitability of the sympathetic division of the autonomic nervous system. A significant slowdown of the pulse during a clinostatic test indicates an increase in the excitability of the parasympathetic department.

Table 6.1.

Continuation of Table 6.1.

Adrenaline test. In a healthy person, subcutaneous injection of 1 ml of 0.1% adrenaline solution after 10 minutes causes pale skin, increased blood pressure, increased heart rate and increased blood glucose levels. If such changes occur faster and are more pronounced, then the tone of the sympathetic innervation is increased.

Skin test with adrenaline. A drop of 0.1% adrenaline solution is applied to the site of the skin injection with a needle. In a healthy person, such an area becomes pale with a pink halo around it.

Atropine test. Subcutaneous injection of 1 ml of 0.1% atropine solution in a healthy person causes dry mouth, decreased sweating, increased heart rate and dilated pupils. With an increase in the tone of the parasympathetic part, all reactions to the administration of atropine are weakened, so the test can be one of the indicators of the state of the parasympathetic part.

To assess the state of functions of segmental vegetative formations, the following tests can be used.

Dermographism. Mechanical irritation is applied to the skin (with the handle of a hammer, the blunt end of a pin). The local reaction occurs as an axon reflex. A red stripe appears at the site of irritation, the width of which depends on the state of the autonomic nervous system. With an increase in sympathetic tone, the stripe is white (white dermographism). Wide stripes of red dermographism, a stripe raised above the skin (elevated dermographism), indicate increased tone of the parasympathetic nervous system.

For topical diagnostics, reflex dermographism is used, which is caused by irritation with a sharp object (drawn across the skin with the tip of a needle). A strip with uneven scalloped edges appears. Reflex dermographism is a spinal reflex. It disappears in the corresponding zones of innervation when the dorsal roots, segments of the spinal cord, anterior roots and spinal nerves are affected at the level of the lesion, but remains above and below the affected area.

Pupillary reflexes. They determine the direct and friendly reaction of the pupils to light, the reaction to convergence, accommodation and pain (dilation of the pupils when pricking, pinching and other irritations of any part of the body).

Pilomotor reflex caused by pinching or applying a cold object (a test tube with cold water) or a cooling liquid (cotton wool soaked in ether) to the skin of the shoulder girdle or the back of the head. On the same half of the chest, “goose bumps” appear as a result of contraction of smooth hair muscles. The reflex arc closes in the lateral horns of the spinal cord, passes through the anterior roots and the sympathetic trunk.

Test with acetylsalicylic acid. After taking 1 g of acetylsalicylic acid, diffuse sweating appears. If the hypothalamic region is affected, its asymmetry is possible. When the lateral horns or anterior roots of the spinal cord are damaged, sweating is disrupted in the area of innervation of the affected segments. When the diameter of the spinal cord is damaged, taking acetylsalicylic acid causes sweating only above the site of the lesion.

Test with pilocarpine. The patient is injected subcutaneously with 1 ml of a 1% solution of pilocarpine hydrochloride. As a result of irritation of postganglionic fibers going to the sweat glands, sweating increases.

It should be borne in mind that pilocarpine excites peripheral M-cholinergic receptors, causing increased secretion of the digestive and bronchial glands, constriction of the pupils, increased tone of the smooth muscles of the bronchi, intestines, gall and bladder, and uterus, but pilocarpine has the most powerful effect on sweating. If the lateral horns of the spinal cord or its anterior roots are damaged in the corresponding area of the skin, sweating does not occur after taking acetylsalicylic acid, and the administration of pilocarpine causes sweating, since the postganglionic fibers that react to this drug remain intact.

Light bath. Warming the patient causes sweating. This is a spinal reflex, similar to the pilomotor reflex. Damage to the sympathetic trunk completely eliminates sweating after the use of pilocarpine, acetylsalicylic acid and body warming.

Skin thermometry. Skin temperature is examined using electrothermometers. Skin temperature reflects the state of blood supply to the skin, which is an important indicator of autonomic innervation. Areas of hyper-, normo- and hypothermia are determined. A difference in skin temperature of 0.5 °C in symmetrical areas indicates disturbances in autonomic innervation.

Electroencephalography is used to study the autonomic nervous system. The method allows us to judge the functional state of the synchronizing and desynchronizing systems of the brain during the transition from wakefulness to sleep.

There is a close connection between the autonomic nervous system and the emotional state of a person, therefore the psychological status of the subject is studied. For this purpose, special sets of psychological tests and the method of experimental psychological testing are used.

6.7. Clinical manifestations of lesions of the autonomic nervous system

When the autonomic nervous system is dysfunctional, a variety of disorders occur. Violations of its regulatory functions are periodic and paroxysmal. Most pathological processes do not lead to the loss of certain functions, but to irritation, i.e. to increased excitability of central and peripheral structures. On the-

disruption in some parts of the autonomic nervous system can spread to others (repercussion). The nature and severity of symptoms are largely determined by the level of damage to the autonomic nervous system.

Damage to the cerebral cortex, especially the limbic-reticular complex, can lead to the development of autonomic, trophic, and emotional disorders. They can be caused by infectious diseases, injuries to the nervous system, and intoxications. Patients become irritable, hot-tempered, quickly exhausted, they experience hyperhidrosis, instability of vascular reactions, fluctuations in blood pressure and pulse. Irritation of the limbic system leads to the development of paroxysms of severe vegetative-visceral disorders (cardiac, gastrointestinal, etc.). Psychovegetative disorders are observed, including emotional disorders (anxiety, restlessness, depression, asthenia) and generalized autonomic reactions.

If the hypothalamic region is damaged (Fig. 6.7) (tumor, inflammatory processes, circulatory disorders, intoxication, trauma), vegetative-trophic disorders may occur: disturbances in the rhythm of sleep and wakefulness, thermoregulation disorder (hyper- and hypothermia), ulcerations in the gastric mucosa, lower part of the esophagus, acute perforations of the esophagus, duodenum and stomach, as well as endocrine disorders: diabetes insipidus, adiposogenital obesity, impotence.

Damage to the autonomic formations of the spinal cord with segmental disorders and disorders localized below the level of the pathological process

Patients may exhibit vasomotor disorders (hypotension), disorders of sweating and pelvic functions. With segmental disorders, trophic changes are observed in the corresponding areas: increased dry skin, local hypertrichosis or local hair loss, trophic ulcers and osteoarthropathy.

When the nodes of the sympathetic trunk are affected, similar clinical manifestations occur, especially pronounced when the cervical nodes are involved. There is impaired sweating and disorder of pilomotor reactions, hyperemia and increased temperature of the skin of the face and neck; due to decreased tone of the laryngeal muscles, hoarseness and even complete aphonia may occur; Bernard-Horner syndrome.

Rice. 6.7.

1 - damage to the lateral zone (increased drowsiness, chills, increased pilomotor reflexes, constriction of the pupils, hypothermia, low blood pressure); 2 - damage to the central zone (impaired thermoregulation, hyperthermia); 3 - damage to the supraoptic nucleus (impaired secretion of antidiuretic hormone, diabetes insipidus); 4 - damage to the central nuclei (pulmonary edema and gastric erosion); 5 - damage to the paraventricular nucleus (adipsia); 6 - damage to the anteromedial zone (increased appetite and behavioral disturbances)

Damage to the peripheral parts of the autonomic nervous system is accompanied by a number of characteristic symptoms. The most common type of pain syndrome that occurs is sympathalgia. The pain is burning, pressing, bursting, and tends to gradually spread beyond the area of primary localization. Pain is provoked and intensified by changes in barometric pressure and ambient temperature. Changes in skin color are possible due to spasm or dilation of peripheral vessels: paleness, redness or cyanosis, changes in sweating and skin temperature.

Autonomic disorders can occur with damage to the cranial nerves (especially the trigeminal), as well as the median, sciatic, etc. Damage to the autonomic ganglia of the face and oral cavity causes burning pain in the area of innervation related to this ganglion, paroxysmalness, hyperemia, increased sweating, in the case lesions of the submandibular and sublingual nodes - increased salivation.

Content

To control metabolism, the functioning of the spinal cord and other internal organs of the body, the sympathetic nervous system, consisting of fibers of nervous tissue, is needed. A characteristic section is localized in the organs of the central nervous system and is characterized by constant control of the internal environment. Excitation of the sympathetic nervous system provokes dysfunction of individual organs. Therefore, such an abnormal condition must be monitored and, if necessary, regulated with medication.

What is the sympathetic nervous system

This is part of the autonomic nervous system, which covers the upper lumbar and thoracic spinal cord, mesenteric nodes, cells of the sympathetic border trunk, and solar plexus. In fact, this section of the nervous system is responsible for the vital activity of cells and maintaining the functionality of the whole organism. In this way, a person is provided with an adequate perception of the world and the body’s reaction to the environment. The sympathetic and parasympathetic departments work together and are structural elements of the central nervous system.

Structure

On both sides of the spine there is a sympathetic trunk, which is formed from two symmetrical rows of nerve ganglia. They are connected to each other using special bridges, forming a so-called “chain” with an unpaired coccygeal node at the end. This is an important element of the autonomic nervous system, which is characterized by autonomous operation. To ensure the required physical activity, the design distinguishes the following departments:

cervical of 3 nodes;

thoracic, which includes 9-12 nodes;
area of the lumbar segment of 2-7 nodes;
sacral, consisting of 4 nodes and one coccygeal.

From these sections, impulses move to the internal organs and support their physiological functionality. The following structural links are distinguished. In the cervical region, the nervous system controls the carotid arteries, in the thoracic region - the pulmonary and cardiac plexuses, and in the peritoneal region - the mesenteric, solar, hypogastric, and aortic plexuses. Thanks to postganglionic fibers (ganglia), there is a direct connection with the spinal nerves.

Functions

The sympathetic system is an integral part of human anatomy, located closer to the spine, and is responsible for the proper functioning of internal organs. Controls the flow of blood through vessels and arteries, filling their branches with vital oxygen. Among the additional functions of this peripheral structure, doctors highlight:

increasing the physiological abilities of muscles;

decrease in the absorption and secretory capacity of the gastrointestinal tract;
increased blood sugar and cholesterol;
regulation of metabolic processes, metabolism;
providing increased strength, frequency and rhythm of the heart;
the flow of nerve impulses to the fibers of the spinal cord;
dilated pupils;
innervation of the lower extremities;
increased blood pressure;
release of fatty acids;
decreased tone of smooth muscle fibers;
adrenaline rush in the blood;
increased sweating;
stimulation of sensitive centers;
dilation of the bronchi of the respiratory system;
decreased saliva production.

Sympathetic and parasympathetic nervous system

The interaction of both structures supports the vital functions of the whole organism; dysfunction of one of the departments leads to serious diseases of the respiratory, cardiovascular, and musculoskeletal systems. The effect is exerted through nerve tissues consisting of fibers that provide excitability of impulses and their redirection to internal organs. If one of the diseases predominates, the choice of high-quality medications is made by the doctor.

Any person should understand the purpose of each department, what functions it provides to maintain health. The table below describes both systems, how they can manifest themselves, and what effect they can have on the body as a whole:

Nervous sympathetic structure		Parasympathetic nervous structure
Department name	Functions for the body	Functions for the body
Cervical region	Dilated pupils, decreased salivation	Constriction of pupils, control of saliva secretion
Thoracic region	Bronchial dilatation, decreased appetite, increased heart rate	Narrowing of the bronchi, decreased heart rate, increased digestion
Lumbar	Inhibition of intestinal motility, production of adrenaline	Possibility of gallbladder stimulation
Sacral section	Bladder relaxation	Bladder contraction

Differences between the sympathetic and parasympathetic nervous systems

Sympathetic nerves and parasympathetic fibers can be located in a complex, but at the same time they provide different effects on the body. Before contacting your doctor for advice, it is recommended to find out the differences between the sympathetic and parasympathetic systems in structure, location and functionality in order to approximately understand the potential focus of pathology:

Sympathetic nerves are located locally, while parasympathetic fibers are more discrete.

Preganglionic sympathetic fibers are short and small, and parasympathetic fibers are often elongated.
The nerve endings of the sympathetic are adrenergic, while the parasympathetic are cholinergic.
The sympathetic system is characterized by white and gray connecting branches, but these are absent in the parasympathetic nervous system.

What diseases are associated with the sympathetic system?

With increased excitability of the sympathetic nerves, nervous conditions develop that cannot always be eliminated by self-hypnosis. Unpleasant symptoms are reminiscent of themselves already in the primary form of the pathology and require immediate medical attention. The doctor recommends to beware of the following diagnoses and to consult your doctor in time for effective treatment.