Innervation of internal organs. Anatomical and physiological aspects

Afferent Innervation. INTEROCEPTION ANALYZER

Study of the sources of sensitive innervation internal organs and conducting pathways of interoception is not only of theoretical interest, but also of great practical importance. There are two interrelated goals for which the sources of sensitive innervation of organs are studied. The first of them is the knowledge of the structure of the reflex mechanisms that regulate the activity of each organ. The second goal is the knowledge of the pathways of pain stimuli, which is necessary for the creation of scientifically based surgical methods anesthesia. On the one hand, pain is a signal of an organ disease. On the other hand, it can develop into severe suffering and cause serious changes in the functioning of the body.

Interoceptive pathways carry afferent impulses from receptors (interoceptors) of the viscera, blood vessels, smooth muscles, skin glands, etc. Feelings of pain in the internal organs can occur under the influence of various factors (stretching, compression, lack of oxygen, etc.)

The interoceptive analyzer, like other analyzers, consists of three sections: peripheral, conductive and cortical (Fig. 16).

The peripheral part is represented by a variety of interoceptors (mechano-, baro-, thermo-, osmo-, chemoreceptors) - the nerve endings of the dendrites of the sensitive cells of the nodes cranial nerves(V, IX, X), spinal and autonomic nodes.

The nerve cells of the sensory ganglia of the cranial nerves (I neuron) are the first source of afferent innervation of the internal organs. Peripheral processes (dendrites) of pseudo-unipolar cells follow in the composition nerve trunks and branches of the trigeminal, glossopharyngeal and vagus nerve to the internal organs of the head, neck, chest and abdominal cavity(stomach, duodenum, liver).

The second source of afferent innervation of the internal organs is the spinal nodes (I neuron), containing the same sensitive pseudo-unipolar cells as the nodes of the cranial nerves. It should be noted that the spinal nodes contain neurons both innervating skeletal muscles and skin, and innervating viscera and blood vessels. Therefore, in this sense, the spinal nodes are somatic-vegetative formations.

To the internal organs of the abdominal cavity and pelvis, the bulk of the afferent fibers pass as part of the splanchnic nerves and further, passing through the ganglia of the autonomic plexuses, and through the secondary plexuses reaches the internal organs.

To the blood vessels of the limbs and the walls of the body, afferent vascular fibers - peripheral processes of sensory cells of the spinal nodes - pass as part of the spinal nerves.

Thus, afferent fibers for internal organs do not form independent trunks, but pass as part of the autonomic nerves.

The organs of the head and vessels of the head receive afferent innervation mainly from the trigeminal and glossopharyngeal nerves. The glossopharyngeal nerve takes part in the innervation of the pharynx and vessels of the neck with its afferent fibers. The internal organs of the neck, chest cavity and the upper "floor" of the abdominal cavity have both vagal and spinal afferent innervation. Most of the internal organs of the abdomen and all organs of the pelvis have only spinal sensory innervation, i.e. their receptors are formed by the dendrites of the cells of the spinal nodes.

The central processes (axons) of pseudo-unipolar cells enter into the sensory roots in the head and spinal cord.

The third source of afferent innervation of some internal organs is the vegetative cells of the second type Dogel, located in intraorganic and extraorganic plexuses. The dendrites of these cells form receptors in the internal organs, the axons of some of them reach the spinal cord and even the brain (I.A. Bulygin, A.G. Korotkov, N.G. Gorikov), following either as part of the vagus nerve or through the sympathetic trunks in posterior roots of the spinal nerves.

In the brain, the bodies of the second neurons are located in the sensory nuclei of the cranial nerves (nucl. spinalis n. trigemini, nucl. solitarius IX, X nerves).

In the spinal cord, interoceptive information is transmitted through several channels: along the anterior and lateral spinal thalamic tracts, along the spinal cerebellar tracts, and along the posterior cords - thin and wedge-shaped bundles. Participation of the cerebellum in adaptive-trophic functions nervous system explains the existence of wide interoceptive pathways leading to the cerebellum. Thus, the bodies of the second neurons are also located in the spinal cord - in the nuclei of the posterior horns and the intermediate zone, as well as in the thin and sphenoid nuclei medulla oblongata.

The axons of the second neurons are sent to the opposite side and, as part of the medial loop, reach the nuclei of the thalamus, as well as the nuclei of the reticular formation and the hypothalamus. Consequently, in the brainstem, firstly, a concentrated bundle of interoceptive conductors is traced, following in the medial loop to the nuclei of the thalamus (III neuron), and secondly, there is a divergence of autonomic pathways heading to many nuclei of the reticular formation and to the hypothalamus. These connections ensure the coordination of the activities of numerous centers involved in the regulation of various vegetative functions.

The processes of the third neurons go through the posterior leg of the internal capsule and end on the cells of the cerebral cortex (IV neuron), where awareness occurs. pain. Usually these sensations are diffuse in nature, do not have an exact localization. IP Pavlov explained this by the fact that the cortical representation of interoceptors has little life practice. So, patients with repeated attacks of pain associated with diseases of the internal organs, determine their localization and nature much more accurately than at the beginning of the disease.

In the cortex, vegetative functions are represented in the motor and premotor zones. Information about the work of the hypothalamus enters the cortex of the frontal lobe. Afferent signals from the respiratory and circulatory organs - to the cortex of the insula, from the abdominal organs - to the postcentral gyrus. The cortex of the central part of the medial surface of the cerebral hemispheres (limbic lobe) is also part of the visceral analyzer, participating in the regulation of the respiratory, digestive, genitourinary systems, and metabolic processes.

Afferent innervation of internal organs is not segmental. The internal organs and vessels are distinguished by a multiplicity of sensory innervation pathways, among which the majority are fibers originating from the nearest segments of the spinal cord. These are the main pathways of innervation. The fibers of the additional (roundabout) pathways of innervation of the internal organs pass from the distant segments of the spinal cord.

A significant part of the impulses from the internal organs reaches the autonomic centers of the brain and spinal cord through the afferent fibers of the somatic nervous system due to the numerous connections between the structures of the somatic and autonomic parts of the single nervous system. Afferent impulses from the internal organs and the apparatus of movement can go to the same neuron, which, depending on the situation, ensures the performance of vegetative or animal functions. The presence of connections between the nerve elements of somatic and autonomic reflex arcs causes the appearance of reflected pain, which must be taken into account when making a diagnosis and treating. So, with cholecystitis, there are toothaches and a phrenicus symptom is noted, with anuria of one kidney, there is a delay in the excretion of urine by the other kidney. In diseases of the internal organs, skin zones appear hypersensitivity- hyperesthesia (Zakharyin-Ged zones). For example, with angina pectoris, reflected pains are localized in the left arm, with a stomach ulcer - between the shoulder blades, with damage to the pancreas - girdle pains on the left at the level of the lower ribs up to the spine, etc. Knowing the structural features of segmental reflex arcs, it is possible to influence the internal organs, causing irritation in the area of the corresponding skin segment. This is the basis of acupuncture and the use of local physiotherapy.

EFFERENT INNERVATION

The reflex arcs of the autonomic nervous system can be closed at different levels. The most complex efferent pathways begin in the cerebral cortex (I neuron). The axons of the neurons of the cortex of the frontal lobes are directed to the hypothalamic region of their side, where they end on the cells of the supraoptic and paraventricular nuclei, as well as the nuclei of the mastoid bodies. In addition, the first neurons of the efferent pathway are the nerve cells of the cortex of the temporal lobe, where the taste and olfactory centers are located, associated with the activity of the digestive organs.

The axons of the cortical cells reach the ventromedial hypothalamic nucleus and the infundibulum nucleus (II neuron) as part of the terminal strip and fornix. The processes of the second neurons form a dorsal longitudinal bundle (Schutz), passing through the brain stem, where fibers depart from it to the autonomic nuclei of the III, VII, IX, X cranial nerves (III neuron). In the spinal cord, fibers of the dorsal longitudinal beam adjoin the lateral pyramidal tract and end on the intermediate-lateral nuclei (III neuron).

The last (IV) neuron is located on the periphery in the vegetative nodes.

The influence of the centers of the autonomic nervous system is realized through a direct change in the function of the organ, regulation of vascular tone, and also through an adaptive-trophic effect that ensures the absorption of nutrients from the delivered blood.

The efferent innervation of various internal organs is ambiguous. Organs, which include smooth involuntary muscles, as well as organs with a secretory function, as a rule, receive efferent innervation from both parts of the autonomic nervous system: sympathetic and parasympathetic, which have the opposite effect on the function of the organ.

Excitation of the sympathetic division of the autonomic nervous system causes an increase in heart rate, an increase in blood pressure and blood glucose levels, an increase in the release of hormones from the adrenal medulla, dilation of the pupils and lumen of the bronchi, a decrease in the secretion of glands (except sweat), inhibition of intestinal motility, causes spasm of sphincters .

Excitation of the parasympathetic division of the autonomic nervous system reduces arterial pressure and the level of glucose in the blood (increases the secretion of insulin), slows down and weakens the contraction of the heart, constricts the pupils and the lumen of the bronchi, increases the secretion of the glands, increases peristalsis and reduces the muscles Bladder, relaxes the sphincters.

Depending on the morphofunctional features of a particular organ, the sympathetic or parasympathetic component of the autonomic nervous system may predominate in its efferent innervation. Morphologically, this is manifested in the number of corresponding conductors in the structure and severity of the intraorgan nervous apparatus. In particular, in the innervation of the bladder and vagina, the decisive role belongs to the parasympathetic division, in the innervation of the liver - to the sympathetic.

Some organs receive only sympathetic innervation, such as the pupillary dilator, sweat and sebaceous glands skin, hairy muscles of the skin, spleen, and the sphincter of the pupil and the ciliary muscle - parasympathetic innervation. Only sympathetic innervation has the vast majority of blood vessels. In this case, an increase in the tone of the sympathetic nervous system, as a rule, causes a vasoconstrictive effect. However, there are organs (heart) in which an increase in the tone of the sympathetic nervous system is accompanied by a vasodilating effect.

Internal organs containing striated muscles (tongue, pharynx, esophagus, larynx, rectum, urethra) also receive efferent somatic innervation from the motor nuclei of the cranial or spinal nerves.

Importance to determine the sources of nerve supply to the internal organs is the knowledge of its origin, its movements in the process of ontogenesis. Only from these positions will the innervation, for example, of the heart from the cervical sympathetic nodes, and the gonads from the aortic plexus, be understood.

Efferent vegetative pathways from segmental centers to internal organs and vessels are two-neuronal. The bodies of the first neurons are located in the nuclei of the brain and spinal cord. The bodies of the second - in vegetative

nodes where the impulse switches from preganglionic to postganglionic fibers.

Tables 1-8 present the localization of neurons I and II, as well as the course of pre- and postganglionic sympathetic and parasympathetic fibers.

Sympathetic innervation of the organs of the head (Fig. 17).

Body name	I neuron		II neuron
M. dilatator pupillae	Nucl. intermedio-lateralis C 8, Th 1 - 2	Radices ventrales → trunci nn. spinales → rr. communicantes albi → rr. interganglionares	G. cervicale superius	Pl. caroticus internus → pl. ophthalmicus → g. ciliare → nn. ciliares breves
Lacrimal gland	Nucl. intermedio-lateralis Th 1 - 3	- ∙∙ -	- ∙∙ -	Pl. caroticus internus → pl. ophthalmicus → pl. lacrimalis
Mucous glands of the nose and palate	- ∙∙ -	- ∙∙ -	- ∙∙ -	Pl. caroticus internus → n. petrosus profundus → n. canalis pterygoidei → g. pterygopalatinum → rr. nasales posteriores et nn. palatini
Salivary glands	- ∙∙ -	- ∙∙ -	- ∙∙ -	Pl. caroticus externus

Sympathetic innervation of the organs of the neck (Fig. 18).

Rice. 18. Scheme of sympathetic innervation of the neck organs. 1-rr. communicantes albi; 2-g. cervicale superius; 3-g. cervicale medius; 4-g. cervicale inferius; 5-gg. thoracica tr. sympatici.

Sympathetic innervation of the organs of the chest cavity (Fig. 19, 20).

Body name	I neuron	The course of the preganglionic fibers	II neuron	Course of postganglionic fibers
Trachea, bronchi, lungs	Nucl. intermediolateralis Th 1 - 6	Radices ventrales → trunci nn. spinales → rr. communicantes albi; rr. interganglionares.	Gg. thoracica (1-5) et g. cervicale inferius	Rr. tracheales and bronchiales → pl. pulmonalis
Esophagus	- ∙∙ -	- ∙∙ -	- ∙∙ -	Rr. esophagei → pl. esophageus
Heart	- ∙∙ -	Radices ventrales → trunci nn. spinales → rr. communicantes albi → rr interganglionares	Gg. cervicalia and thoracica (1-5)	N. cardiacus cervicalis superior, medius, inferius et cardiaci thoracici → pl. cardiacus

Sympathetic innervation of the abdominal organs (Fig. 21).

Body name	I neuron	The course of the preganglionic fibers	II neuron	Course of postganglionic fibers
stomach, liver, pancreas, spleen,	Nucl. intermediolateralis Th 6–12	Radices ventrales → trunci nn. spinales → rr. communicantes albi → n. splanchnicus major	Gg. coeliaci, g. mesentericum superius	Pl. gastricus, pl. hepaticus, pl. lienalis
Small intestine, large intestine (to colon descendens)	- ∙∙ -	- ∙∙ -	G. mesentericum superius	Pl. mesentericus superior
Large intestine (colon descendens, colon sigmoideum).	Nucl. intermediolateralis Th 10–12, L 1–2	Radices ventrales → trunci nn. spinales → rr. communicantes albi → rr. interganglionares → nn. splanchnici lumbales	G. mesentericum inferius	Pl. mesentericus inferior
Kidneys, adrenals.	- ∙∙ -	Radices ventrales → trunci nn. spinales → rr. communicantes albi → rr. interganglionares → n. splanchnicus minor et nn. splanchnici lumbales	Gg. aortorenalia*	Pl. renalis, pl. suprarenalis

* The adrenal medulla is innervated by preganglionic sympathetic fibers.

Sympathetic innervation of the pelvic organs and sex glands (Fig. 22, 23).

Body name	I neuron	The course of the preganglionic fibers	II neuron	Course of postganglionic fibers
Rectum, bladder, genitals (except gonads)	Nucl. intermediolateralis L 1-3	Radices ventrales → trunci nn. spinales → rr. communicantes albi → rr. interganglionares → nn. splanchnici lumbales and sacrales	G. mesentericum inferius, gg. pl. hypogastric inferioris	Pl. mesentericus inferior, pl. rectalis, pl. vesicalis, pl. prostaticus, pl. uterovaginalis
Testicle	Nucl. intermediolateralis Th 10–12	Radices ventrales → trunci nn. spinales → rr. communicantes albi → rr. interganglionares → n. splanchnicus minor et nn. splanchnici lumbales	Gg. aortorenalia	Pl. testicularis
Ovary	Nucl. intermediolateralis Th 10–12, L 1–3	Radices ventrales → trunci nn. spinales → rr. communicantes albi → rr. interganglionares → n. splanchnicus minor, nn. splanchnici lumbales and sacrales	Gg. aortorenalia, g. mesentericum inferius, gg. pl. hypogastric inferioris	Pl. ovaricus, pl. mesentericus inferior, pl. uterovaginalis

Parasympathetic innervation of the organs of the head (Fig. 24).

Body name	I neuron	The course of the preganglionic fibers	II neuron	Course of postganglionic fibers
M. sphincter pupillae, m. ciliaris	Nucl. accessorius (III)	N. oculomotorius → radix oculomotoria	G. ciliare	Nn. ciliares breves
Lacrimal gland	Nucl. salivatorius superior (VII)	N. intermediofacialis → n. petrosus major → n. canalis pterygoidei	G. pterygopalatinum	N. maxillaris → n. zygomaticus → n. lacrimalis
Mucous glands of the nose and palate	- ∙∙ -	- ∙∙ -	- ∙∙ -	Rr. nasales posteriores → n. nasopalatinus; nn. palatini
Submandibular and sublingual glands	- ∙∙ -	N. intermediofacialis → chorda tympani → n. lingualis → rr. ganglionares	G. submandibulare	Rr. glandulares
parotid gland	Nucl. salivatorius inferior(IX)	N. glossopharyngeus → n. tympanicus → n. petrosus minor	G. oticum	N. auriculotemporalis
	Rice. 24. Scheme of parasympathetic innervation of the organs of the head. 1 - nucl. accessorius (III); 2 - nucl. salivatorius superior (VII); 3 - nucl. salivatorius inferior (IX); 4 - n. oculomotorius; 5-g. ciliare; 6-gl. lacrimalis; 7 - m. sphincter pupillae; 8 - m. ciliaris; 9-n. petrosus major; 10-g. pterygopalatinum; 11 - chorda tympani; 12-g. submandibular; 13-gl. sublingualis; 14-gl. submandibularis; 15 - n. petrosus minor; 16-g. oticum; 17-gl. parotidea.

Parasympathetic innervation of the neck, thoracic and abdominal organs

Body name	I neuron	The course of the preganglionic fibers	II neuron	Course of postganglionic fibers
Pharynx	Nucl. dorsalis n. vagi	N. vagus → rr. pharyngei → pl. pharyngeus	Gg. terminalia	Pl. pharyngeus
Larynx, thyroid	- ∙∙ -	N. vagus → n. laryngeus superior, n. laryngeus recurrens → n. laryngeus inferior	- ∙∙ -	Pl. laryngeus, pl. thyroideus
Trachea, bronchi, lungs	- ∙∙ -	N. vagus → rr. tracheales and bronchiales → pl. pulmonalis	- ∙∙ -	Pl. pulmonalis
Heart	- ∙∙ -	N. vagus → rr. cardiaci cervicales superiores et inferiores, rr. cardiaci thoracici	- ∙∙ -	Pl. cardiacus
Esophagus	- ∙∙ -	N. vagus → rr. esophagei	- ∙∙ -	Pl. esophageus
Stomach, liver, pancreas, intestines (up to colon sigmoideum), kidneys, adrenal glands	- ∙∙ -	N. vagus → truncus vagalis anterior et posterior → rr gastrici anteriores et posteriores → rr. hepatici and coeliaci	- ∙∙ -	Pl. gastricus, pl. hepaticus, pl. pancreaticus, pl. intestinalis, pl. renalis, pl. suprarenalis
	Rice. 25. Scheme of parasympathetic innervation of the organs of the neck, chest and abdominal cavity. 1 - nucl. dorsalis n. vagi; 2 - n. vagus; 3 - branches of the cervical region n. vagus; 4 - branches of the thoracic n. vagus; 5 - branches of the abdominal n. vagus; 6 - parasympathetic nodes (gg. Terminalia).

Parasympathetic innervation of the pelvic organs and gonads (Fig. 26, 27)

Body name	I neuron	The course of the preganglionic fibers	II neuron	Course of post-ganglionic fibers
Sigmoid and rectum, bladder, genitals (except gonads)	Nucl. intermediolateralis S 2-4	Radices ventrales → trunci nn. spinales → rr. ventrales → pl. sacralis → nn. splanchnici pelvini → pl. hypogastricus inferior	Gg. terminalia	Pl. rectalis, pl. vesicalis, pl. prostaticus (pl. uterovaginalis)
Testicle	Nucl. dorsalis n. vagi	N. vagus → truncus vagalis posterior → rr. coeliaci → pl. testicularis	Gg. terminalia	Pl. visceralis
Ovary	Nucl. dorsalis n. vagi. Nucl. intermediolateralis S 2-4	N. vagus → truncus vagalis posterior → rr. coeliaci → pl. ovaricus Radices ventrales → trunci nn. spinales → pl. sacralis → nn. splanchnici pelvini → pl. hypogastricus inferior	Gg. terminalia	Pl. visceralis

INNERVATION OF BLOOD VESSELS

The nervous apparatus of blood vessels is represented by interoceptors and perivascular plexuses that spread along the course of the vessel in its adventitia or along the border of its outer and middle membranes.

Afferent (sensory) innervation is carried out due to nerve cells spinal nodes and nodes of cranial nerves.

The efferent innervation of the blood vessels is carried out by sympathetic fibers, and the arteries and arterioles experience a continuous vasoconstrictive effect.

Sympathetic fibers go to the vessels of the limbs and trunk as part of the spinal nerves.

The main mass of efferent sympathetic fibers to the vessels of the abdominal cavity and pelvis passes as part of the celiac nerves. Irritation of the splanchnic nerves causes narrowing of blood vessels, transection - a sharp expansion of blood vessels.

A number of researchers have discovered vasodilating fibers that are part of some somatic and autonomic nerves. Perhaps only the fibers of some of them (chorda tympani, nn. splanchnici pelvini) are of parasympathetic origin. The nature of most vasodilating fibers remains unclear.

T.A. Grigoryeva (1954) substantiated the assumption that the vasodilating effect is achieved as a result of contraction of not circular, but longitudinally or obliquely oriented muscle fibers vascular wall. Thus, the same impulses brought by sympathetic nerve fibers cause a different effect - vasoconstrictor or vasodilator, depending on the orientation of the smooth muscle cells themselves in relation to the longitudinal axis of the vessel.

Another mechanism of vasodilation is also allowed: relaxation of the smooth muscles of the vascular wall as a result of the onset of inhibition in the autonomic neurons innervating the vessels.

Finally, one cannot exclude the expansion of the lumen of the vessels as a result of humoral influences, since humoral factors can organically enter the reflex arc, in particular, as its effector link.

LITERATURE

1. Bulygin I.A. Afferent link of interoceptive reflexes. - Minsk, 1971.

2. Golub D.M. The structure of the peripheral nervous system in human embryogenesis. Atlas. - Minsk, 1962.

3. Grigoryeva T.A. Innervation of blood vessels. - M.: Medgiz, 1954.

4. Knorre A.G., Lev I.D. autonomic nervous system. - L.: Medicine, 1977. - 120 p.

5. Kolosov N.G. Innervation of internal organs and the cardiovascular system. - M. - L., 1954.

6. Kolosov N.G. vegetative node. - L.: Nauka, 1972. - 52 p.

7. Lavrentiev B.I. Theory of the structure of the autonomic nervous system. -M.: Medicine, 1983. - 256 p.

8. Lobko P.I. Celiac plexus and sensitive innervation of internal organs. - Minsk: Belarus, 1976. - 191 p.

9. Lobko P.I., Melman E.P., Denisov S.D., Pivchenko P.G. Autonomic Nervous System: Atlas: Tutorial. - Mn.: Vysh. Shk., 1988. - 271 p.

10. Nozdrachev A.D. Vegetative reflex arc. - L .: Nauka, 1978.

11. Nozdrachev A.D. Physiology of the autonomic nervous system. - L.: Medicine, 1983. - 296 p.

12. Pervushin V.Yu. Autonomic nervous system and innervation of internal organs (textbook). - Stavropol, 1987. - 78 p.

13. Prives M.G., Lysenkov N.K., Bushkovich V.I. Human anatomy. Ed. 9. - M.: Medicine, 1985. - S. 586-604.

14. Sapin M.R. (ed.). Human Anatomy, v.2. - M.: Medicine, 1986. - S. 419-440.

15. Semenov S.P. Morphology of the autonomic nervous system and interoreceptors. - L.: Leningrad University, 1965. - 160 p.

16. Turygin V.V. Structural and functional organization and pathways of the autonomic nervous system. - Chelyabinsk, 1988. - 98 p.

17. Turygin V.V. Structural and functional characteristics of the pathways of the central nervous system. - Chelyabinsk, 1990. - 190 p.

18. Howlike I. Autonomic nervous system.: Anatomy and physiology. - Bucharest, 1978. - 350 p.

19. Barr M.L., Kiernan J.A. The human nervous system. - Fifth edition. - New York, 1988. - P. 348-360.

20. Voss H., Herrlinger R. Taschenbuch der Anatomie. - Band III. - Jena, 1962. - S. 163-207.

Foreword ................................................................ ...............................................3

general characteristics autonomic nervous system ........................... 3

A brief outline of the history of the study of the autonomic nervous system.....4

Functions of the autonomic nervous system ............................................................... 5

Centers of the autonomic nervous system ............................................................... ...6

Reflex arc of the autonomic nervous system .............................................. 8

Vegetative nodes .................................................................. ...................................ten

The multi-storey structure of the mechanism of regulation of autonomic

functions................................................. ................................................…eleven

Morpho-functional differences between autonomic and somatic

nervous system .............................................................. ...................................…13

Development of the autonomic nervous system. Phylogeny .............................. 14

Embryogenesis .................................................. .........................................…fifteen

Sympathetic and parasympathetic divisions and their differences ........…..17

Sympathetic division of the autonomic nervous system .............................. 18

Prevertebral nodes and vegetative plexuses.......................................24

Parasympathetic division of the autonomic nervous system .............................. 28

Innervation of internal organs. afferent innervation.

Interoceptive analyzer ................................................……………….. 32

Efferent innervation .................................................................. ....................................35

Innervation of blood vessels .............................................................. ......…..44

Literature................................................. .........................................................…...45

Shcherbakova M.N. Autonomic nervous system: a textbook - Grodno: GrGMI

The textbook contains modern data on the structural organization of the autonomic nervous system.

General issues of the structure and development of the autonomic nervous system, structural features of the sympathetic and parasympathetic divisions are considered. Sources presented autonomic innervation internal organs and vessels.

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1.
2.
3.
4.
5.
6.
Complex autonomic reflex arc
Methods for the approach of vegetative fibers to the innervated
structures.
Morphofunctional differences between the somatic part of the NS and
vegetative.
Types of innervation.
Essence of afferent and efferent innervations.
Innervation of blood vessels and internal organs of the head, neck,
thoracic, abdominal and pelvic cavities.
1

Participates in the innervation of internal organs as
somatic nervous system and autonomic
The somatic nervous system provides
Afferent (sensitive) innervation and;
Efferent (motor) somatic
innervation (maintenance of tone and reduction
striated muscle)
2

The principle of innervation of internal organs

The autonomic nervous system provides:
Afferent innervation without CNS involvement
on the principle of axon reflex;
and efferent autonomic
(sympathetic and parasympathetic)
a) motor (maintaining tone and
contraction of smooth muscles and cardiac muscle)
b) secretory (change in secretory
activity of glandular cells)
3

The essence of afferent innervation is:
in the perception of receptor formations of energy
irritants from the external and internal environment;
transforming it into a nerve impulse
(excitation);
transfer it to the central nervous system, on the basis of which
the body's response is formed
(it is being adapted).
The essence of efferent innervation is
transmission of a nerve impulse generated
based on afferent innervation, to workers
organs (effectors), which are muscles
and glandular tissue, resulting in
regulation of tone and degree of muscle contraction or
regulation of the allocation of quantity and quality
secret.
4

Almost all internal organs are
three types of innervation:
afferent
efferent somatic
and autonomic (sympathetic and
parasympathetic).
5

Ways of approach of afferent nerve fibers:

AT
composition
structures
(branches)
spinal nerves
As part of the structures (branches) of the cranial
nerves
AT
composition
structures
(branches)
vegetative
trunks,
plexus,
nerves.
(For example, to
sympathetic
nerves
sensitive fibers are suitable
through white connecting branches) 6

Ways of approach of efferent somatic motor) nerve fibers:

To
organs of the head and neck (muscles
tongue, soft palate, pharynx, larynx,
upper third of the esophagus, eye
apple, middle ear) - in the composition
branches of the corresponding cranial
nerves (III, IV, V, VI, VII, IX, X, XI, XII pairs
cranial
nerves),
to
outdoor
sphincter of the rectum and urethra
7
composition of the genital nerve.

Ways of approach of efferent vegetative (motor and secretory) nerve fibers:

Parasympathetic nerve fibers:
in the branches of cranial nerves (from
parasympathetic nuclei III, VII, IX, X pairs)
as part of the branches of the splanchnic nerves (from
sacral segments of the spinal cord)
Sympathetic nerve fibers:
within branches of spinal nerves
(on white connecting branches)
as part of the branches of the perivasal plexuses
8

VII, IX, X pairs of cranial nerves.

10.

11.

efferent
sympathetic
innervation
internal organs are derived from sympathetic
ganglia
–
paravertebral
and
prevertebral
through
sympathetic
plexus.
Efferent parasympathetic innervation
internal organs of the head are obtained from
parasympathetic nuclei 3, 7, 9 pairs of cranial
nerves; neck, thoracic and abdominal organs
cavities to the sigmoid colon - from
parasympathetic nucleus 10 pairs of cranial
nerves; sigmoid colon and all organs of small
pelvis - from the lateral intermediate substance
sacral segments SII–IV.
11

12. INSERTION OF VESSELS

innervation.
Afferent
innervation
vessels
heads
carried out by sensitive fibers in the composition
branches of cranial nerves (V, IX, X).
Afferent innervation of the vessels of the neck, trunk,
limbs and internal organs
sensory fibers in the branches
spinal nerves.

12

13. 14. INSERTION OF VESSELS

Efferent
innervation
vessels.
The vast majority of vessels have only
sympathetic efferent innervation.

from
all
sympathetic
nodes
(parai
prevertebral)

connecting branches.
14

15. WHAT IS INNERVATED BY THE ANS?

All smooth muscle
a) in the wall of internal organs
b) in the wall of blood vessels
c) in the sense organs (in the skin - m.errector pili,
mm.ciliares, sphincter et dilatator pupilae)
heart muscle
glandular cells
ANS FUNCTION - Adaptive-trophic
15

16. Localization of neuron bodies in a three-neuron vegetative reflex arc.

Body of the first afferent (sensory)
neuron (it is common for somatic and
autonomic reflex arcs) is located
in the ganglia of the spinal and cranial nerves.
The body of the second intercalary neuron is in
lateral columns of the spinal cord C8-L2, S2-S4
segments and in the parasympathetic nuclei III, VII,
IX, X pairs of cranial nerves.
The body of the third efferent (motor or
secretory) neuron is localized in all
vegetative ganglia.
16

17. The method of approach of vegetative fibers to the innervated organs.

Vegetative fibers reach
innervated organs consisting of:
1) somatic SMN and CN and their
branches,
2) autonomic nerves,
3) autonomic plexuses and their
branches.
17

18.

1
2
3
18

19. Morphofunctional differences between the somatic part of the nervous system and the autonomic part (see previous lecture)

Somatic
Type of difference
nervous system
1. Nerve Output Relative
fibers (nerves) segmentation
from the CNS.
fiber exit
(nerves)
2. Availability
myelinated
myelin
nerve fibers
shells
3. Objects
striated
efferent
transverse innervation
striped
(skeletal)
muscle.
Vegetative
nervous system
Focal exit
fibers (nerves)
Mostly
unmyelinated
nerve fibers
-smooth mouse.
the cloth,
- striated
cardiac
muscle,
- glandular
19
cells

20.

Type of difference
4. Structure
efferent link
reflex arc
Somatic nervous
system
Single neuron (axon
motor neuron
reaches without interruption
effector)
Autonomic nervous
system
two-neuron,
which distinguish between pre and postganlionic
nerve fibers.
5. Places of localization
bodies of refl neurons
arcs:
a) afferent
neuron;
b) intercalary neuron;
c) efferent neuron
- in somatic ganglia - in somatic
SMN I H).
ganglia of SMN and CN.
-in the posterior horns
spinal cord and
sensitive nuclei
CHN.
-in the lateral horns
spinal cord and
vegetative
(parasympathetic)
CN nuclei.
- in the anterior horns
spinal cord and
motor nuclei of CN
- in vegetative
(sympathetic and
parasympathetic)
20
ganglia.

21. TYPES OF INNERVATION

I. Afferent (sensitive)
II. Efferent:
1. Somatic (motor) only according to
ratio of skeletal muscles
2. Vegetative (sympathetic and
parasympathetic)
a) motor (in relation to smooth
muscles and muscles of the heart)
b) secretory (in relation to
glandular cells)
21

22. The essence of afferent innervation is:

in perception by receptor formations
energy of stimuli from external and internal
environment;
2. transformation of this energy into a nerve impulse
(excitation);
3. transmission of nerve impulses in the instances of the central nervous system, on
on the basis of which the response is formed
organism (providing its adaptation to
constantly changing conditions).
Part of the nerve impulses along the conduction
paths of analyzers reach their cortical nuclei,
in which, on the basis of higher analysis and synthesis
of these impulses in humans arise
sensations, ideas, concepts, generalizations
22
about the world around (cognitive function)
1.

23. The essence of efferent innervation is:

in the transmission of a nerve impulse formed on
basis of afferent innervation, from nuclear formations
CNS, to the working organs (effectors), which are
muscles and glandular cells. Distinguish as it was
noted above, efferent somatic and
autonomic innervation.
Efferent somatic (motor) innervation
is to regulate skeletal muscle tone and
realization of the effect of their reduction;
Efferent autonomic (motor) sympathetic and

tone of the cardiac and smooth muscles and the implementation of the effect
their abbreviations;
Efferent autonomic (secretory) sympathetic and
parasympathetic innervation regulates
excretion of quantity and quality of secretion by glands. 23

24.

Almost all organs of the human body
have
sensitive
innervation,
which is carried out mainly
somatic part of the NS.
Organs in the structure of which there is at least
one type of muscle tissue or
glandular cells, such as internal
bodies
have
and
efferent
innervation, which is carried out as
somatic and vegetative
departments of the National Assembly.
24

25.

Thus, the vast majority
There are three types of internal organs
innervation:
1. afferent.
2. efferent autonomic innervation
(sympathetic and parasympathetic).
3. And the organs, which include
striated muscles, have
more
and
efferent
somatic
innervation.
Afferent and efferent somatic
innervation
internal
bodies
25
carried out by somatic SMN and CN.

26.

Efferent
motor
and
secretory
autonomic sympathetic and parasympathetic
innervation
carried out
vegetative
fibers and nerves.
Efferent autonomic innervation.
a) Efferent sympathetic innervation of organs
carried out from a single sympathetic nucleus, n.
intermediolateralis (C8 - L2) of the spinal cord. nervous
impulses from the neurons of this nucleus go along their axons
(preganglionic
fibers),
reach
paravertebral or prevertebral ganglia.
In these ganglia, there is a switch of nerve
impulses to ganglion neurons. along the axons of these
neurons (postganglionic fibers) that
form sympathetic perivasal plexuses,
nerve impulses approach the innervated
26
organ structures.

27.

b) Efferent parasympathetic innervation
organs carried out from nuclear structures
head and pelvic parts of the parasympathetic
systems are parasympathetic nuclei III, VII, IX, X
pairs of cranial nerves and parasympathetic nucleus, n.
intermediolateralis S2-4 of the spinal cord.
Nerve impulses from parasympathetic neurons
nuclei go along their axons (preganglionic
fibers),
reach
periorgan
and
intraorgan ganglia. In these ganglia
switching nerve impulses to neurons
ganglia.
By
axons
these
neurons
(postganglionic fibers) nerve impulses
suitable for innervated organ structures.
27

28.

Often over a certain distance
preganglionic and postganglionic
sympathetic and parasympathetic fibers
form vegetative (sympathetic and
parasympathetic) nerves. Therefore, at
parsing
innervation
bodies
often
appear autonomic nerves having
own name.
28

29. INSERTION OF VESSELS

Vessels have afferent and efferent
innervation.
Afferent
innervation
vessels
heads
carried out by sensory fibers
the composition of the branches V, IX, X pairs of cranial nerves, and
vessels of the neck, trunk, limbs and internal
organs - sensitive fibers in the composition
branches of SMN and n. vagus (X).
Sensory fibers to internal organs
suitable as part of the sympathetic nerves, in which
they pass along the white connecting branches, and
also in the branches of the vagus nerve.
All sensory fibers are dendrites
afferent
pseudo-unipolar
neurons
somatic ganglia SMN and CN
29

30.

31.

Efferent innervation of blood vessels. Vessels
have only sympathetic efferent
innervation.
1) To the smooth muscles of the internal vessels
organs, postganglionic fibers fit into
sympathetic perivasal plexus
from
all
sympathetic
nodes
(parai
prevertebral)
2) To the smooth muscles of the vessels of the striated muscles, postganglionic fibers
suitable as part of the branches of the spinal cord
nerves, to which they enter through the gray
connecting branches.
31

32. INNERVATION OF THE INTERNAL ORGANS

innervated
bodies and
structures
Afferent
somatic
innervation
Head
1.
Mucous
mouth,
nose, sky,
pharynx,
larynx and
conjunctiva
lower
century
branches
and
n. trigeminus
(v)
Efferent innervation of the ANS
sympathetic
Parasympathetic
columna
intermediolateralis,
radix ventralis
nn. spinales, rr.
communicantes albi*,
Ganglion cervicale
superius tr. sympathici,
n.caroticus internus,
plexus caroticus
internus, n. petrosus
profundus.
N. salivatorius sup.
(VII), n.intermedius,
n.petrosus major,
g.pterigopalatinum:
1.rr.nasales
posterior mediales,
laterales and inferiores
2.nn.palatinus major et
palatini minores
3.r.pharyngeus
Efferent
somatic
innervation
No
32

33.

Innervated organs and
structures
2.
Language
Afferent somatic.
innervation
General
sensitivity: n.
lingualis (V).
Taste
sensitivity:
papillae anterior 2/3
mucous membrane of the tongue
taste fibers
chorda tympani (VII), and
papillae posterior 1/3
mucous membrane of the tongue
taste fibers rr.
linguales (IX).
In the area of
epiglottis - r.
laryngeus superior (x)
Effer. cute
inn-i
Efferent parasympathetic inn-I
Efferent somatic.
inn-i
n.salivatori- Muscles
us sup.(VII), language -
–«–
n. intermediate;
chorda
tympani
(VII).
n.
hypogloss
us(XII)
33

34.

3.
branches
Soft 1) n.
sky
palatinus
major, nn.
–«–
palatini
minores (V)
2) nn. palatini et n. nasopalatinus
(IX)
4.
lexus
*, Ganglion
Pharynx pharyngeus, cervicale
formed by superius
IX and X CN tr.sympathic
i, rr.
et tr.
sympathicus laryngopharyngei
n.salivatori 1) m.tensor veli
-us
palatini-n.
sup.(VII),
mandibularis (V)
n. intermediate;
n. petrosu
major
2) m. levator veli
palatini, m. palato
glossus, m.
palatopharyngeus, m.
uvulae-rr. palatini (X)
1) m.stylopharyngeus -
n. glossopharyngeus
(IX)
2) mm. constric-tor
pharyngis superior,
Pharynge medius, inferior; m.
salpingopharyngeus 34i (X).
rr. pharyngei (X)
n. salivatori
-us inf.
(IX)
n.dorsalis
nervi vagi
(X), rr.

35.

Innervirue
my organs
and structures
Afferent
somatic
innervation
5.Lower n. linjaw-gualis
naya and
(v)
sublingual
glands
6.
parotid
gland
n.
auriculotemporales
(v)
Efferent innervation of the ANS
sympathetic
*, Ganglion cervicale
superius tr. sympathici,
nn.carotici externi, plexus
caroticus externus
- \\ -
Parasympathetic
N. salivatorius sup.
(n.intermedius), chorda
tympani (VII),
g.submandibulare et
g.sublinguale.
N. salivatorius inferior,
n.tympanicus
n. petrosus minor (IX)
g.oticum,
n.aoriculotemporalis (V)
35

36.

37.

38.

4 mm.
sphincter
pupilae et
ciliaris
vascular
shells
eye
apples
n.
ophthal
micus,
nn.
ciliares
longi et
breves
m.dilator
pupilae
vascular
shells
eye
apples
- \\ -
No
n.oculomotorius
accessorius (III),
radix
parasympatheticus,
g.ciliare,
nn.ciliares breves
(V)
*
n.caroticus
internus
pl.caroticus
internus
pl. ophthalmicus
No
38

39.

Neck
IX and X CN et
larynx,
tr.
trachea,
sympathicus
thyroid and
parathyroid
glands
*, Ganglia
cervicales superius,
medium,
cervicothoracicum
(stellatum)
tr.sympathici.
nn. carotici externi,
plexus caroticus
externus.
1. Nucl.dorsalis
n.vagi, cervical
branches (X)
39

40.

Thoracic
cavity
Esophagus
Lung
Heart
Feels
spruce
branches
n.vagus and
sympathetic
nerves
Ganglii thoracici (С2-5)
tr.sympathici,
aortic
plexus
*,
1) n.cardiacus
cervicalis superior (from
upper neck. node)
2) - \\ - medius (from
medium shein. node)
3) - \\ - inferior (from
lower neck. node)
4) nn.cardiaci
thoracici (from upper
chest nodes
tr.sympathici.)
Nucl.dorsalis n.vagi
(X), thoracic branches
n.vagi
Rami cardiaci n.vagi:
a) rami cardiaci
superiores (from
n.laryngeus superior)
b) rami cardiaci
inferiores (from
n.laryngeus reccurens and
thoracic part n.vagi)
40
plexus cardiacus superficialis et profundus

41.

Pericardium
Nucl.dorsalis
pectoral
*
Upper n.vagi (X),
branches n.
chest
(thoracic
vagus(X),
truncus branch nodes) (X)
branches n.
sympathicus
phrenicus:
rr.pericardi
aphrenic
us
41

42.

43.

Abdominal
cavity
1. Stomach,
thin and
thick
guts up
sigmoid
hepar,
pancreas, ren,
lies,
gl. suprarenalis
(cortex)
Abdominal
branches
1)n.vagus
2)n.splanch
nici major
3)-\\-minor
4)
n.phrenicus
sinister,
5) nn.
splanchnici
lumbales
N.dorsalis
nervi vagi
1) Lower
(X)
pectoral gangll. tr. (abdominal
sympathetic,
branches)
n.splanchnicus
major
2)-\\-minor
3) Ganglia
coeliaca,
aortorenalia,
pl. mesentericum
sup. et inf.
(pl.caeliacus)
*
43

44.

45.

2.
1.N. splan Sigmoid- chnici
naya and
pelvini
straight
intestines;
3. uterus,
uterine
pipes,
seed
bubbles,
prostate,
ovary,
testicle
Ganglia sacralia
trunci sympathici
a)pl.
intermesentericus,
mesentericus
inferior,
hypogastricus
superior
b) Nn.
hypogastrici
dexter and sinister
c) plexus
hypogastrici
inferiores
Nuclei
parasympathetic S2-4,
n.n.
splanchnici
pelvini.

1. The cranial nucleus of Yakubovich is located:

1. in the diencephalon

2. in the medulla oblongata

3. in the midbrain

4. in telencephalon

2. In which part of the brain is Yakubovich's nucleus located?

1. in the intermediate

2. oblong

3. average

4. in the end

3. The dorsal nucleus of the vagus nerve is:

1. motor

2. sympathetic

3. parasympathetic

4. sensitive

4. Parasympathetic conductors are composed of:

1. I pair of head nerves

2. II pairs of head nerves

3. 3rd pair of head nerves

4 V pairs of head nerves

5. Parasympathetic ganglia include:

1. superior mesenteric node

2. spinal ganglion

3. pterygopalatine ganglion

4. celiac ganglion

6. Parasympathetic innervation of the pelvic organs is carried out from:

2. lateral intermediate nuclei of the thoracic segments of the spinal cord

3. lateral intermediate nuclei of the lumbar segments of the spinal cord

4. lateral intermediate nuclei of the sacral segments of the spinal cord

7. Sympathetic centers are localized in the following department of the central nervous system:

1. in the midbrain

2. in the medulla oblongata

3. in the spinal cord

4 in diencephalon

8. Pterygopalatine ganglion receives preganglionic conductors from

1. Yakubovich and Perlia kernels

2. dorsal nucleus of the vagus nerve

4. lower salivary nucleus

9. Intermediate lateral nuclei gray matter spinal cord lie in:

1. anterior horns of the gray matter of the spinal cord

2. posterior horns of the gray matter of the spinal cord

3. lateral horns of the gray matter of the spinal cord

4. in the central part of the gray matter of the spinal cord

10. From which autonomic nuclei is the parasympathetic innervation of the pelvic organs carried out

1. dorsal nucleus of the vagus nerve

2. lateral intermediate nuclei of the thoracic segments

3. lateral intermediate nuclei of the lumbar segments

4. lateral intermediate nuclei of the sacral segments

11. Which vegetative nodes belong to the X pair

1. paraorganic

2. intramural

3. paravertebral

4. prevertebral

12. White connecting branches have:

1. all spinal nerves

2. thoracic spinal nerves

13. Which nerves contain parasympathetic fibers to the pelvic organs

1. great and small splanchnic nerves

2. lumbar splanchnic nerves

3. sacral splanchnic nerves

4. pelvic splanchnic nerves

14. From which nucleus originate the vegetative conductors of the intermediate nerve

1. dorsal nucleus of the vagus nerve

2. superior salivary nucleus

3. lower salivary nucleus

4. Yakubovich kernels

15. In which part of the CNS are the sympathetic centers located?

1. in the midbrain

2. in the rhomboid brain

3. in the spinal cord

4. in the diencephalon

16. Which nucleus of the gray matter of the spinal cord is sympathetic

1. own

2. breastfeeding

3. intermediate medial

4 intermediate lateral

17. Along the gray connecting branches, sympathetic conductors are sent to:

1. head and neck organs

2. breast organs

3. abdominal organs

4. soma

18. White connecting branches contain:

1. parasympathetic preganglionic

2. parasympathetic postganglionic

3. sympathetic preganglionics

4. sympathetic postganglionics

19. Gray connecting branches have:

1. all spinal nerves

2. thoracic spinal nerves

3. sacral spinal nerves

4. coccygeal spinal nerves

20. The celiac (solar) plexus innervates:

1. neck organs

2. organs of the chest cavity

3. upper abdominal organs

4. pelvic organs

21. The solar plexus does not contain:

1. sympathetic fibers

2. parasympathetic fibers

3. motor conductors

4. sensitive fibers

22. Gray connecting branches contain

1. parasympathetic preganglionic fibers

2. parasympathetic postganglionic fibers

3. sympathetic preganglionic fibers

4. sympathetic postganglionic fibers

23. Gray connecting branches represent the path of sympathetic conductors to

1. to the organs of the head and neck

2. to the organs chest

3. to the abdominal organs

4. to catfish

24. Internal nerves contain:

1. sympathetic preganglionics only

2. only sympathetic postganglionics

3. sympathetic preganglionic and postganglionic

4. sympathetic and parasympathetic preganglionic

25. spinal nerves having gray connecting branches

1. all

2. none

3. breast only

4. sacral only

26. Solar plexus innervates organs

1. upper floor of the peritoneal cavity

2. middle floor of the peritoneal cavity

3. ground floor peritoneal cavity

4. chest cavity

27. Topography of the solar plexus

1. anterior semicircle thoracic aorta

2. anterior semicircle of the abdominal aorta

3. aortic bifurcation

4. anterior semicircle of the inferior vena cava

28. In what part of the brain does the arc of the pupillary reflex close?

1. in the intermediate

2. average (at the level of the superior colliculus)

3. on average (at the level of the lower colliculi)

4. in the bridge

29. Which nerve carries out the parasympathetic innervation of the bladder

1. wandering

2. large internal

3. sacral splanchnic

4. pelvic splanchnic

30. Vegetative conductors of the intermediate nerve begin:

1. from the dorsal nucleus of the vagus nerve

2. from the superior salivary nucleus

3. from the lower salivary nucleus

4. from Yakubovich's core

31. The following are involved in the innervation of the stomach:

1. celiac plexus

2. superior mesenteric plexus

3. inferior mesenteric plexus

4. hypogastric plexus

32. Branches of what autonomic plexuses are involved in the innervation of the liver

1. sunny

2. superior mesenteric

3. inferior mesenteric

4. hypogastric

33. Branches of which autonomic plexuses are involved in the innervation of the spleen

1.sunny

2. superior mesenteric

3. inferior mesenteric

4. hypogastric

34. Branches of what autonomic plexuses are involved in the innervation of the uterus and its appendages

1. solar

2. superior mesenteric

3. inferior mesenteric

4. hypogastric

35. In innervation small intestine takes part:

1. celiac and superior mesenteric plexus

Afferent Innervation. INTEROCEPTION ANALYZER

The study of the sources of sensitive innervation of the internal organs and the conducting pathways of interoception is not only of theoretical interest, but also of great practical importance. There are two interrelated goals for which the sources of sensitive innervation of organs are studied. The first of them is the knowledge of the structure of the reflex mechanisms that regulate the activity of each organ. The second goal is the knowledge of the pathways of pain stimuli, which is necessary for the creation of scientifically based surgical methods of anesthesia. On the one hand, pain is a signal of an organ disease. On the other hand, it can develop into severe suffering and cause serious changes in the functioning of the body.

Interoceptive pathways carry afferent impulses from receptors (interoceptors) of the viscera, blood vessels, smooth muscles, skin glands, etc. Pain sensations in the internal organs can occur under the influence of various factors (stretching, compression, lack of oxygen, etc.)

The interoceptive analyzer, like other analyzers, consists of three sections: peripheral, conductive and cortical (Fig. 18).

The peripheral part is represented by a variety of interoceptors (mechano-, baro-, thermo-, osmo-, chemoreceptors) - the nerve endings of the dendrites of the sensory cells of the nodes of the cranial nerves (V, IX, X), spinal and autonomic nodes.

The nerve cells of the sensory ganglia of the cranial nerves are the first source of afferent innervation of the internal organs. Peripheral processes (dendrites) of pseudo-unipolar cells follow as part of the nerve trunks and branches of the trigeminal, glossopharyngeal and vagus nerves to the internal organs of the head, neck, chest and abdominal cavity (stomach, duodenal intestine, liver).

The second source of afferent innervation of the internal organs is the spinal nodes, containing the same sensitive pseudo-unipolar cells as the nodes of the cranial nerves. It should be noted that the spinal nodes contain neurons both innervating skeletal muscles and skin, and innervating viscera and blood vessels. Therefore, in this sense, the spinal nodes are somatic-vegetative formations.

The peripheral processes (dendrites) of the neurons of the spinal nodes from the trunk of the spinal nerve pass as part of the white connecting branches into the sympathetic trunk and pass in transit through its nodes. To the organs of the head, neck and chest, afferent fibers follow as part of the branches of the sympathetic trunk - cardiac nerves, pulmonary, esophageal, laryngeal-pharyngeal and other branches. To the internal organs of the abdominal cavity and pelvis, the bulk of the afferent fibers pass as part of the splanchnic nerves and further, passing through the ganglia of the autonomic plexuses, and through the secondary plexuses reaches the internal organs.

To the blood vessels of the limbs and the walls of the body, afferent vascular fibers - peripheral processes of sensory cells of the spinal nodes - pass as part of the spinal nerves.

Thus, afferent fibers for internal organs do not form independent trunks, but pass as part of the autonomic nerves.

The central processes (axons) of pseudo-unipolar cells enter the sensory roots into the brain and spinal cord.

In the brain, the bodies of the second neurons are located in the sensory nuclei of the cranial nerves (nucl. spinalis n. trigemini, nucl. solitarius IX, X nerves).

In the spinal cord, interoceptive information is transmitted through several channels: along the anterior and lateral spinal thalamic tracts, along the spinal cerebellar tracts, and along the posterior cords - thin and wedge-shaped bundles. The participation of the cerebellum in the adaptive-trophic functions of the nervous system explains the existence of wide interoceptive pathways leading to the cerebellum. Thus, the bodies of the second neurons are also located in the spinal cord - in the nuclei of the posterior horns and the intermediate zone, as well as in the thin and sphenoid nuclei of the medulla oblongata.

The processes of the third neurons go through the posterior leg of the internal capsule and end on the cells of the cerebral cortex, where the awareness of pain occurs. Usually these sensations are diffuse in nature, do not have an exact localization. IP Pavlov explained this by the fact that the cortical representation of interoceptors has little life practice. So, patients with repeated attacks of pain associated with diseases of the internal organs, determine their localization and nature much more accurately than at the beginning of the disease.

A significant part of the impulses from the internal organs reaches the autonomic centers of the brain and spinal cord through the afferent fibers of the somatic nervous system due to the numerous connections between the structures of the somatic and autonomic parts of the single nervous system. Afferent impulses from the internal organs and the apparatus of movement can go to the same neuron, which, depending on the situation, ensures the performance of vegetative or animal functions. The presence of connections between the nerve elements of somatic and autonomic reflex arcs causes the appearance of reflected pain, which must be taken into account when making a diagnosis and treating. So, with cholecystitis, there are toothaches and a phrenicus symptom is noted, with anuria of one kidney, there is a delay in the excretion of urine by the other kidney. In diseases of the internal organs, skin zones of hypersensitivity appear - hyperesthesia (Zakharyin-Ged zones). For example, with angina pectoris, reflected pains are localized in the left arm, with a stomach ulcer - between the shoulder blades, with damage to the pancreas - girdle pains on the left at the level of the lower ribs up to the spine, etc. Knowing the structural features of segmental reflex arcs, it is possible to influence the internal organs, causing irritation in the area of the corresponding skin segment. This is the basis of acupuncture and the use of local physiotherapy.

EFFERENT INNERVATION

Excitation of the parasympathetic division of the autonomic nervous system reduces blood pressure and blood glucose levels (increases insulin secretion), slows down and weakens heart contractions, constricts the pupils and the lumen of the bronchi, increases the secretion of glands, increases peristalsis and reduces the muscles of the bladder, relaxes sphincters.

Some organs receive only sympathetic innervation, for example, the pupillary dilator, the sweat and sebaceous glands of the skin, the hair muscles of the skin, the spleen, and the sphincter of the pupil and the ciliary muscle receive parasympathetic innervation. Only sympathetic innervation has the vast majority of blood vessels. In this case, an increase in the tone of the sympathetic nervous system, as a rule, causes a vasoconstrictive effect. However, there are organs (heart) in which an increase in the tone of the sympathetic nervous system is accompanied by a vasodilating effect.

Internal organs containing striated muscles (tongue, pharynx, esophagus, larynx, rectum, urethra) receive efferent somatic innervation from the motor nuclei of the cranial or spinal nerves.

Important for determining the sources of nerve supply to the internal organs is the knowledge of its origin, its movements in the process of evolution and ontogenesis. Only from these positions will the innervation, for example, of the heart from the cervical sympathetic nodes, and the gonads from the aortic plexus, be understood.

A distinctive feature of the nervous apparatus of internal organs is the multi-segmentation of the sources of its formation, the multiplicity of paths connecting the organ with the central nervous system and the presence of local centers of innervation. This may explain the impossibility of complete denervation of any internal organ by surgery.

Efferent vegetative pathways to internal organs and vessels are two-neuronal. The bodies of the first neurons are located in the nuclei of the brain and spinal cord. The bodies of the latter are in the vegetative nodes, where the impulse switches from preganglionic to postganglionic fibers.

Sources of Efferent Autonomic Innervation of Internal Organs

Organs of the head and neck

Parasympathetic innervation. First neurons: 1) accessory and median nucleus of the third pair of cranial nerves; 2) the upper salivary nucleus of the VII pair; 3) lower salivary nucleus of the IX pair; 4) dorsal nucleus of the X pair of cranial nerves.

Second neurons: near-organ nodes of the head (ciliary, pterygopalatine, submandibular, ear), intraorgan nodes of the X pair of nerves.

sympathetic innervation. The first neurons are the intermediate-lateral nuclei of the spinal cord (C 8 , Th 1-4).

The second neurons are the cervical nodes of the sympathetic trunk.

The organs of the chest

Parasympathetic innervation. The first neurons are the dorsal nucleus of the vagus nerve (X pair).

Sympathetic innervation. The first neurons are the intermediate-lateral nuclei of the spinal cord (Th 1-6).

The second neurons are the lower cervical and 5-6 upper thoracic nodes of the sympathetic trunk. The second neurons for the heart are located in all cervical and upper thoracic nodes.

Abdominal organs

Parasympathetic innervation. The first neurons are the dorsal nucleus of the vagus nerve.

The second neurons are near-organ and intra-organ nodes. The exception is the sigmoid colon, which is innervated as organs of the pelvis.

Sympathetic innervation. The first neurons are the intermediate-lateral nuclei of the spinal cord (Th 6-12).

The second neurons are the nodes of the celiac, aortic and inferior mesenteric plexus (II order). The chromophin cells of the adrenal medulla are innervated by preganglionic fibers.

The organs of the pelvic cavity

Parasympathetic innervation. The first neurons are the intermediate-lateral nuclei of the sacral spinal cord (S 2-4).

The second neurons are near-organ and intra-organ nodes.

Sympathetic innervation. The first neurons are the intermediate-lateral nuclei of the spinal cord (L 1-3).

The second neurons are the lower mesenteric node and the nodes of the upper and lower hypogastric plexuses (II order).

INNERVATION OF BLOOD VESSELS

Afferent (sensory) innervation is carried out by the nerve cells of the spinal nodes and nodes of the cranial nerves.

The efferent innervation of the blood vessels is carried out by sympathetic fibers, and the arteries and arterioles experience a continuous vasoconstrictive effect.

Sympathetic fibers go to the vessels of the limbs and trunk as part of the spinal nerves.

TA Grigoryeva (1954) substantiated the assumption that the vasodilating effect is achieved as a result of contraction of not circular, but longitudinally or obliquely oriented muscle fibers of the vascular wall. Thus, the same impulses brought by sympathetic nerve fibers cause a different effect - vasoconstrictor or vasodilator, depending on the orientation of the smooth muscle cells themselves in relation to the longitudinal axis of the vessel.

Another mechanism of vasodilation is also allowed: relaxation of the smooth muscles of the vascular wall as a result of the onset of inhibition in the autonomic neurons innervating the vessels.

The spinal cord is one of the most important parts of the human nervous system. This accumulation of nerve cells and connective tissue carries information from the brain to the muscles, skin, internal organs, that is, to all parts of the body in a reciprocal way.
The spinal cord begins at the base of the brain (Fig. 1), goes from the medulla oblongata and passes through a canal tube formed by other vertebrae.
The spinal cord ends in the first lumbar vertebra with a large number of fibers that stretch to the end of the spine and attach the spinal cord to the coccyx.
From the spinal cord through the holes in the arches of the vertebrae, nerve fibers depart, serving different parts of the body.
On fig. 3 and in tables 1 and 2 marked and labeled segments of the spinal cord that innervate various internal organs and muscle systems. Each segment is responsible for a specific part of the human body.
Along its length, the spinal cord consists of 31 pairs of nerve fibers: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, one coccygeal. The roots of the sensory nerves are attached to the back of the spinal cord, the roots of the motor nerves to the front. Each pair of fibers controls a specific part of the body.

Rice. 3. Segmental innervation of internal organs and muscular systems:C- cervical region; D- thoracic region; L- lumbar; S - sacral department.
Numerical designations - serial number of the vertebra

A logical question arises: what does the sentence "spinal cord injury" mean - a sentence often accompanied by medical diagnosis"fractured spine"?
In a spinal cord injury, the connection between the brain and the part of the body below the injury is interrupted, and its signals do not pass. The greater the disruption of communication, the more severe the consequences of the injury. So, an injury at the level of the cervical vertebrae causes paralysis of all four limbs, loss of sensation in most of the body and disruption of the internal organs, up to breathing. Trauma at a lower level (thoracic or lumbar) causes immobility only lower extremities and disruption of the internal organs located in the pelvis.
Conscious actions come from the brain, but, becoming reflex, are transferred to the jurisdiction of the spinal cord, that is, the brain programs the order of actions. In the "data bank" already at birth, its role in controlling respiration, heartbeat, blood circulation, digestion, excretion and reproduction functions was determined. Countless daily activities - walking, eating, speaking, etc. - are programmed from childhood.
Each nerve functions normally if the spine is stretched, if it is straight, strong and flexible. If the spine shortens, the distance between the vertebrae decreases, and the nerves exiting through the foramina of the vertebral arches (Fig. 1) are compressed.

Table 1

When the fibers in the upper part of the neck are compressed, a person has severe headaches. When squeezing the nerves of the chest, a disorder of the digestive organs is caused. Impact on the nerve fibers located just below can affect the intestines and kidneys.
Tables 1 and 2 provide fairly detailed information on the segmental innervation of the internal organs. It can be seen from them that there is no such part of the body that the vertebral nervous system would not act on.

table 2

If the spine is subject to overexertion or sharp blows, vertebral disc may burst, and the gelatinous mass of the nucleus through the outer shell can enter the spinal canal-"pipe". This is how a hernia is formed. intervertebral disc(Fig. 1). Deep displacement of the disc into the canal can put severe pressure on the spinal cord and even cut off many bodily functions located below the level of the herniation. In addition, the vertebrae, devoid of elastic support, rub against each other and can pinch the nerve exiting the spinal cord.
However, not every spinal injury leads to a violation of the spinal cord and its functions. There are cases when, when falling, a person damaged several processes of the vertebrae and remained not only alive, but also quite healthy. With several fractures of the vertebral bodies, the brain may not be injured mechanically, but only temporarily - even up to a year - "turn off", just as it happens with the brain during a strong concussion. Therefore, by itself, a spinal fracture does not yet lead to permanent disability. In such cases, they say: "I escaped with a slight fright ..." - and, after lying down for the prescribed months, the patient safely gets on his feet.
It happens the other way around: the spinal cord is damaged when the spine is intact or almost intact. This happens with stab or gunshot wounds, electrical injuries or tumors, viral diseases or (in rare cases) hemorrhages of nearby vessels.