Sinusitis

Autonomic innervation of internal organs. Sympathetic division of the autonomic nervous system

VEGETATIVE INNERVATION OF INTERNAL ORGANS

Parameter name	Meaning
Article topic:	VEGETATIVE INNERVATION OF INTERNAL ORGANS
Rubric (thematic category)	All sorts of different things

AFFERENT INNERVATION. INTEROCEPTIVE ANALYZER

The study of the sources of sensitive innervation of internal organs and interoceptive pathways is not only of theoretical interest, but also of great practical importance. There are two interrelated goals for which the sources of sensory innervation of organs are studied. The first of them is knowledge of the structure of reflex mechanisms that regulate the activity of each organ. The second goal is to understand the pathways of pain stimulation, which is necessary to create scientifically based surgical methods of pain relief. On the one hand, pain is a signal of 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. Sensations 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. 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.

Nerve cells of the sensory ganglia of the cranial nerves are the first source of afferent innervation of internal organs. Peripheral processes (dendrites) of pseudounipolar 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, thoracic and abdominal cavities (stomach, duodenum, liver).

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

The peripheral processes (dendrites) of the neurons of the spinal ganglia from the trunk of the spinal nerve pass as part of the white connecting branches into the sympathetic trunk and pass in transit through the ᴇᴦο nodes. Afferent fibers travel to the organs of the head, neck and chest 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 in “transit” through the ganglia of the autonomic plexuses, and through the secondary plexuses reaches the internal organs.

Afferent vascular fibers - peripheral processes of sensory cells of the spinal ganglia - pass as part of the spinal nerves to the blood vessels of the limbs and walls of the body.

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 the 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 neck vessels with its afferent fibers. The internal organs of the neck, chest cavity and upper “floor” of the abdominal cavity have both vagal and spinal afferent innervation. Most of the internal organs of the abdomen and all pelvic organs have only spinal sensory innervation, i.e. their receptors are formed by the dendrites of spinal ganglion cells.

The central processes (axons) of pseudounipolar cells enter the brain and spinal cord as part of the sensory roots.

The third source of afferent innervation of some internal organs are vegetative cells of the second Dogel type, located in the intraorgan and extraorgan 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 dorsal roots of 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: through the anterior and lateral spinothalamic tracts, through the spinocerebellar tracts and through the posterior funiculi - the thin and cuneate fasciculi. 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 located in the spinal cord - in the nuclei of the dorsal horns and intermediate zone, and similarly in the thin and wedge-shaped nuclei of the medulla oblongata.

The axons of the second neurons are directed to the opposite side and, as part of the medial loop, reach the nuclei of the thalamus, and similarly the nuclei of the reticular formation and the hypothalamus. It follows that in the brain stem, firstly, a concentrated bundle of interoceptive conductors can be traced, following in the medial loop to the nuclei of the thalamus (III neuron), and secondly, there is a divergence of vegetative pathways heading to many nuclei of the reticular formation and to the hypothalamus. These connections ensure coordination of the activities of numerous centers involved in the regulation of various autonomic 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, where the awareness of pain occurs. Usually these sensations are diffuse in nature and do not have precise localization. I.P. Pavlov explained this by the fact that the cortical representation of interoceptors has little life practice. Thus, patients with repeated attacks of pain associated with diseases of the internal organs determine their location 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 functioning of the hypothalamus enters the frontal lobe cortex. Afferent signals from the respiratory and circulatory organs - to the insular cortex, 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 similarly part of the visceral analyzer, participating in the regulation of the respiratory, digestive, genitourinary systems, and metabolic processes.

The afferent innervation of internal organs is not segmental in nature. Internal organs and vessels are distinguished by a multiplicity of sensory innervation pathways, the majority of which are fibers originating from the nearest segments of the spinal cord. These are the main routes of innervation. Fibers of additional (roundabout) pathways of innervation of internal organs pass from 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 internal organs and the movement apparatus can arrive at the same neuron, which, based on the current 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 referred pain, which must be taken into account when making a diagnosis and treatment. Thus, 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 increased sensitivity appear - hyperesthesia (Zakharyin-Ged zones). For example, with angina pectoris, referred pain is localized in the left arm, with a stomach ulcer - between the shoulder blades, with damage to the pancreas - girdle pain 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 internal organs, causing irritation in the area of the corresponding skin segment. This is what acupuncture and the use of local physiotherapy are based on.

EFFERENT INNERVATION

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

Excitation of the sympathetic part of the autonomic nervous system causes increased heart rate and intensification, increased blood pressure and blood glucose levels, increased release of hormones from the adrenal medulla, dilation of the pupils and bronchial lumen, decreased secretion of glands (except sweat glands), inhibition of intestinal motility, causing spasm of the sphincters .

Stimulation of the parasympathetic part of the autonomic nervous system reduces blood pressure and blood glucose levels (increases insulin secretion), reduces and weakens heart contractions, constricts the pupils and bronchial lumen, increases glandular secretion, increases peristalsis and contracts the bladder muscles, and relaxes the sphincters.

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

Some organs receive only sympathetic innervation, for example, the dilator pupil, 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. The vast majority of blood vessels have only sympathetic innervation. Moreover, an increase in the tone of the sympathetic nervous system, as a rule, causes a vasoconstrictor effect. However, there are organs (the heart) in which an increase in the tone of the sympathetic nervous system is accompanied by a vasodilator effect.
Concept and types, 2018.

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 internal organs is knowledge of the origin, 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 sources of formation, the multiplicity of pathways connecting the organ with the central nervous system and the presence of local innervation centers. This can explain the impossibility of complete denervation of any internal organ surgically.

Efferent autonomic 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 VEGETATIVE INNERVATION OF INTERNAL ORGANS

VEGETATIVE INNERVATION OF INTERNAL ORGANS - concept and types. Classification and features of the category "VEGETATIVE INNERVATION OF INTERNAL ORGANS" 2017-2018.

Afferent innervation of internal organs and blood vessels is carried out by nerve cells of the sensory ganglia of the cranial nerves, spinal ganglia, and also vegetative ganglia (I neuron). Peripheral processes (dendrites) of pseudounipolar cells follow as part of the nerves to the internal organs. The central processes enter the brain and spinal cord as part of the sensory roots. Bodies II neurons located in the spinal cord - in the nuclei of the dorsal horns, in the nuclei of the thin and wedge-shaped fasciculi of the medulla oblongata and the sensory nuclei of the cranial nerves. The axons of the second neurons are directed to the opposite side and, as part of the medial loop, reach the nuclei of the thalamus (III neuron).

The processes of the third neurons end on the cells of the cerebral cortex, where the awareness of pain occurs. The cortical end of the analyzer is located mainly in the pre- and postcentral gyri (IV neuron).

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

Excitation sympathetic division the autonomic nervous system causes increased heart rate and intensification, increased blood pressure and blood glucose levels, increased release of hormones from the adrenal medulla, dilation of the pupils and bronchial lumen, decreased secretion of glands (except sweat glands), spasm of the sphincters and inhibition of intestinal motility.

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

SENSE ORGANS

Introduction

Sense organs belong to the sensory systems. They contain the peripheral ends of the analyzers, protecting the receptor cells of the analyzers from adverse effects and creating favorable conditions for their optimal functioning.

According to I.P. Pavlov, each analyzer consists of three parts: peripheral part - receptor which perceives irritations and transforms them into a nerve impulse, conductive transmitting impulses to nerve centers, central, located in the cerebral cortex (cortical end of the analyzer), which analyzes and synthesizes information. Thanks to the sense organs, the body’s relationship with the external environment is established.

The sense organs include: the organ of vision, the organ of hearing and balance, the organ of smell, the organ of taste, the organ of tactile, pain and temperature sensitivity, the motor analyzer, the interoceptive analyzer.

The motor analyzer is described in detail in the chapter “Central Nervous System. Conducting pathways”, and about the interoceptive analyzer – in the chapter “Autonomic Nervous System”.

Organ of vision

Eye, oculus, consists of the eyeball and surrounding auxiliary organs.

Eyeball, bulbus oculi, is located in the orbit and has the appearance of a ball, more convex in front. Its anterior and posterior poles are distinguished. The straight line passing through the poles is called the visual axis of the eye. The eyeball is composed of three membranes: fibrous, vascular, and retinal, surrounding the inner core of the eye (Fig. 1).

fibrous membrane, tunica fibrosa bulbi, is a derivative of mesoderm, located externally, performs a protective function and serves as a site of muscle attachment. It is divided into: posterior section - sclera or tunica albuginea, which is a dense white connective tissue plate and the anterior section - cornea, this is the more convex transparent part of the fibrous membrane, reminiscent of a watch glass, which belongs to the light-refracting media of the eye. It has a large number of nerve endings and is devoid of blood vessels; it has high permeability, which is used for the administration of drugs. At the border of the cornea and sclera, in the thickness of the latter, there is a venous sinus of the sclera, into which fluid outflows from the anterior chamber of the eye.

Fig.1. Diagram of the eyeball. 1 – sclera; 2 – cornea; 3 – the choroid itself; 4 – retina; 5 – iris; 6 – iridocorneal angle; 7 – lens; 8 – vitreous body; 9 – anterior chamber; 10 – rear camera; 11 – yellow spot; 12 – optic nerve.

choroid, tunica vasculosa bulbi, like fibrous, develops from the mesoderm, is rich in blood vessels, located inward from the fibrous membrane. It has three sections: the choroid itself, the ciliary body and the iris.

The choroid itself, choroidea, makes up 2/3 of the choroid and is its posterior section. Between the adjacent surfaces of the choroid proper and the sclera there is a slit-like perivascular space, which allows the choroid proper to move during accommodation.

ciliary body,corpus ciliare- thickened part of the choroid. The location of the ciliary body coincides with the junction of the sclera and the cornea. The anterior part of the ciliary body contains about 70 ciliary processes, the basis of which are blood capillaries that produce aqueous humor. From the ciliary body, the fibers of the ciliary girdle (ligament of Zinn) begin, which is attached to the lens capsule. The thickness of the ciliary body is the ciliary muscle, m. ciliaris, involved in accommodation. When tense, this muscle relaxes the ligament, and through it the lens capsule, which becomes more convex. When the muscle relaxes, the ligament of Zinn tightens and the lens becomes flatter. The atrophy of muscle fibers that occurs with age and their replacement with connective tissue leads to a weakening of accommodation.

Iris or iris,iris, makes up the anterior part of the choroid and looks like a disk with a hole in the center - pupil. The base (stroma) of the iris is represented by connective tissue with vessels located in it. In the thickness of the stroma there are smooth muscles: circularly located muscle fibers that constrict the pupil, m. sphincter pupillae, and radial fibers that dilate the pupil, m. dilatator pupillae. Thanks to the muscles, the iris acts as a diaphragm, regulating the amount of light entering the eye. The anterior surface of the iris contains the pigment melanin, the varying amount and nature of which determines the color of the eyes.

Retina, retina- inner lining of the eyeball. It develops from an outgrowth of the anterior medullary vesicle, which turns into an optic vesicle on a stalk, and then into a double-walled goblet. The retina is formed from the latter, and the optic nerve is formed from the stalk. The retina consists of two layers: the outer pigment layer and the inner photosensitive layer (nerve part). Based on function and structure, the inner layer of the retina is divided into two parts: posterior visual, pars optica retinae, containing photosensitive elements (rods, cones) and anterior blind, pars caeca retinae, covering the posterior surface of the iris and the ciliary body, where there are no photosensitive elements. The optic nerve forms at the back of the retina. The site where it exits is called the optic disc, where rods and cones are absent (blind spot). Lateral to the optic disc, it is round in shape yellow spot, macula, containing only cones and is the place of greatest visual acuity.

Inner nucleus of the eye

The inner core of the eye consists of transparent light-refracting media: the lens, the vitreous body and the aqueous humor.

Lens, lens, develops from the ectoderm and is the most important light-refracting medium. It has the shape of a biconvex lens and is enclosed in a thin transparent capsule. The ligament of Zinn extends from the lens capsule to the ciliary body, which acts as a suspensory apparatus for the lens. Due to the elasticity of the lens, its curvature easily changes when viewing objects at a far or near distance (accommodation). When the ciliary muscle contracts, the fibers of the zonular ligament relax, and the lens becomes more convex (set to near vision). Relaxation of the muscle leads to tension in the ligament and flattening of the lens (distance vision).

Vitreous body, corpus vitreum- a transparent jelly-like mass lying behind the lens and filling the cavity of the eyeball.

Aqueous moisture produced by the capillaries of the ciliary processes and fills the anterior and posterior chambers of the eye. It is involved in nourishing the cornea and maintaining intraocular pressure.

The anterior chamber of the eye is the space between the anterior surface of the iris and the posterior surface of the cornea. Along the periphery, the anterior and posterior walls of the chamber converge, forming the iridocorneal angle, through the slit-like spaces of which aqueous humor flows into the venous sinus of the sclera, and from there into the veins of the eye.

The posterior chamber of the eye is narrower, located between the iris, lens and ciliary body, and communicates with the anterior chamber of the eye through the pupil.

Thanks to the circulation of aqueous humor, a balance is maintained between its secretion and absorption, which is a factor in stabilizing intraocular pressure.

INNERVATION , supplying organs and tissues with nerves. There are centripetal, or afferent nerves, through which irritation is brought to the central nervous system, and centrifugal, or efferent nerves, through which impulses are transmitted from the centers to the periphery. Only its centrifugal nerves are directly related to the work of any organ; The centripetal nerves coming from this apparatus do not necessarily participate in its functioning. In the case when the work of an organ is stimulated or regulated by reflex, the participation of centripetal nerves is necessary. It should be emphasized that the number of centripetal nerves, the irritation of which can cause a reflex impulse in one centrifugal nerve, is very large. Already within one spinal cord, the number of The number of afferent nerves entering a given segment significantly exceeds the number of efferent nerves leaving it (Sherrington's funnel). In the presence of a cerebral cortex, irritation of any afferent nerve can, in the order of a conditioned reflex, cause an impulse in any efferent nerve and, consequently, any activity of the body. There is no known activity of the body that would proceed completely independently of nervous influences. In some cases, the operation of the effector apparatus occurs solely under the influence of nerve impulses. This is, for example, the activity of all skeletal muscles, the edges of which are determined exclusively by reflex irritation or direct irritation of the nerve centers. In these cases, transection of the centrifugal nerve causes complete loss of function of this apparatus. In other rays, the work of an organ is caused by both nerve impulses (reflex) and the direct impact of certain stimuli on the tissue of a given organ. This is for example work of the gastric glands, pancreas. Finally, there are cases where nerve impulses have only a regulatory effect on the functioning of an organ (a typical example is cardiac activity). In some cases, I. has a relatively minor significance for the functioning of the organ (for example, the secretion of urine by the kidneys) or an unclear significance (for example, the secretion of bile by the liver). Only very few processes appear to be immune from direct nervous influence (eg, the diffusion of gases through the wall of the alveoli). It has now been proven that metabolic processes in tissues also depend on nervous influences. From what has been said, it is clear that for the normal functioning of an organ, its connection with the centers through the centrifugal nerves is necessary. The latter are divided into somatic, directly coming from the anterior horns of the spinal cord to the innervated apparatus (muscles), and autonomic, passing through the ganglia (see. Autonomic nervous system). Apparently most, if not all, of the body’s apparatuses have dual innervation—autonomic and somatic [muscles (Bouquet, Orbeli)] or sympathetic and parasympathetic innervation (for example, heart, intestines, stomach). Most data force us to admit that a special formation is included between the nerve and the innervated apparatus, which plays an important role in the processes of transmission of excitation. According to some authors (Langley), this formation (substance /S) is not identical with the ending of the nerve. However, the question of the existence of a special intermediate link between the nerve and the innervated apparatus cannot be finally resolved (Lapicque). Gist. side of the issue - see Nerve endings. As a rule, not only those parts of the central nervous system from which the nerves that innervate the corresponding organs originate are relevant to the functioning of organs. The higher parts of the brain are always related to the work of all organs. When talking about the center of any activity (for example, the respiratory center), it should be borne in mind that we cannot talk about a narrowly limited anat. areas. Along with the main center (for a number of vegetative functions), located in the medulla oblong., there are always subordinate centers in the spinal cord. Even after the centers are completely excluded, certain primitive innervation mechanisms are gradually restored due to the nerve ganglia and those nerve cells that are located in the organ itself (the above applies only to the area of innervation by the autonomic nervous system). - Regarding the intimate mechanism of innervation processes and There is no exact and complete information about the mechanism of transmission of excitation from the nerve to the innervated device. Loewy's experiments showed that when the cardiac nerves are irritated, some kind of chemical is produced. a substance that produces the same effect as irritation of the nerves themselves. Samoilov expressed a similar view regarding the mechanism of transmission of irritation from nerve to muscle. From this point of view, the transmission of excitation is reduced, as it were, to the secretion by the nerve ending of a certain chemical agent that has a specific effect. Recently, it has been proven that the transfer of irritation from a nerve to a muscle is associated with the breakdown of creatine phosphoric acid into its components. - For theories of the conduction of excitation along the nerve and theories of central innervation processes, see Nervous system, Ionic theory of excitation. Innervation of individual organs - see relevant organs and Autonomic nervous system. G - Conradi.

AFFERENT INNERVATION. INTEROCEPTIVE ANALYZER

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

Nerve cells of the sensory ganglia of the cranial nerves are the first source of afferent innervation of internal organs. Peripheral processes (dendrites) of pseudounipolar 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, duodenum intestine, liver).

The second source of afferent innervation of internal organs is the spinal nodes, which contain the same sensitive pseudounipolar 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 the viscera and blood vessels. Consequently, in this sense, the spinal nodes are somatic-vegetative formations.

The peripheral processes (dendrites) of the neurons of the spinal ganglia from the spinal nerve trunk pass as part of the white connecting branches into the sympathetic trunk and pass in transit through its nodes. Afferent fibers travel to the organs of the head, neck and chest 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.

Afferent vascular fibers - peripheral processes of sensory cells of the spinal ganglia - pass through the spinal nerves to the blood vessels of the limbs and walls of the body.

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

The central processes (axons) of pseudounipolar cells enter the brain and spinal cord as part of the sensory roots.

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: through the anterior and lateral spinothalamic tracts, through the spinocerebellar tracts and through the posterior funiculi - the thin and cuneate fasciculi. The participation of the cerebellum in the adaptive-trophic functions of the nervous system explains the existence of broad 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 dorsal horns and intermediate zone, as well as in the thin and wedge-shaped nuclei of the medulla oblongata.

The axons of the second neurons are directed 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 brain stem, firstly, a concentrated bundle of interoceptive conductors can be 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 coordination of the activities of numerous centers involved in the regulation of various autonomic functions.

In the cortex, autonomic functions are represented in the motor and premotor zones. Information about the functioning of the hypothalamus enters the frontal lobe cortex. Afferent signals from the respiratory and circulatory organs - to the insular cortex, 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.

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 numerous connections between the structures of the somatic and autonomic parts of the unified nervous system. Afferent impulses from internal organs and the movement apparatus can arrive at the same neuron, which, depending on the current 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 referred pain, which must be taken into account when making a diagnosis and treatment. So, with cholecystitis, there are toothaches and a phrenicus symptom is noted; with anuria of one kidney, there is a delay in urine output from the other kidney. In diseases of the internal organs, skin zones of increased sensitivity appear - hyperesthesia (Zakharyin-Ged zones). For example, with angina pectoris, referred pain is localized in the left arm, with a stomach ulcer - between the shoulder blades, with damage to the pancreas - girdle pain 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 internal organs by 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 sympathetic part of the autonomic nervous system causes an increase in heart rate and contractions, 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 bronchial lumen, a decrease in the secretion of glands (except sweat glands), inhibition of intestinal motility, and causes spasm of the sphincters .

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

Depending on the morphofunctional characteristics 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, the parasympathetic department plays a decisive role in the innervation of the bladder and vagina, and the sympathetic one in the innervation of the liver.

Some organs receive only sympathetic innervation, for example, the dilator pupil, 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. The vast majority of blood vessels have only sympathetic innervation. In this case, an increase in the tone of the sympathetic nervous system, as a rule, causes a vasoconstrictor effect. However, there are organs (the heart) in which an increase in the tone of the sympathetic nervous system is accompanied by a vasodilator 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 internal organs is 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 multisegmental nature of the sources of its formation, the multiplicity of pathways connecting the organ with the central nervous system and the presence of local innervation centers. This may explain the impossibility of complete denervation of any internal organ surgically.

SOURCES OF EFFERENT VEGETATIVE INNERVATION OF INTERNAL ORGANS

Organs of the head and neck

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

Second neurons: periorgan nodes of the head (ciliary, pterygopalatine, submandibular, auricular), intraorgan nodes of the X pair of nerves.

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

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

Organs of the chest cavity

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

Sympathetic innervation. The first neurons are the interlateral 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. Second neurons for the heart are located in all cervical and upper thoracic ganglia.

Abdominal organs

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

The second neurons are periorgan and intraorgan nodes. The exception is the sigmoid colon, which is innervated as pelvic organs.

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

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

Organs of the pelvic cavity

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

The second neurons are periorgan and intraorgan nodes.

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

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

INNERVATION OF BLOOD VESSELS

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

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

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

Sympathetic fibers travel to the vessels of the limbs and torso as part of the spinal nerves.

The bulk of the efferent sympathetic fibers to the vessels of the abdominal cavity and pelvis passes through the splanchnic nerves. Irritation of the splanchnic nerves causes a narrowing of the blood vessels, while transection causes a sharp dilation of the blood vessels.

A number of researchers have discovered vasodilator 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 vasodilator fibers remains unclear.

T.A. Grigorieva (1954) substantiated the assumption that the vasodilator 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 possible: relaxation of the smooth muscles of the vascular wall as a result of inhibition in the autonomic neurons innervating the vessels.

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

Security questions

1. General characteristics of the sympathetic department:

A. central department (sympathetic centers);

b. peripheral section (paravertebral and prevertebral ganglia, pre- and postganglionic conductors);

2. The concept of white and gray connecting branches.

3. Patterns of sympathetic innervation of the soma, internal organs of the head, neck and chest cavity, and abdominal cavity.

4. Connection of sympathetic conductors with sensory fibers of a spinal nature (the concept of double afferent innervation of internal organs).

5. Borderline sympathetic trunk (nodes, sections, branches and areas of their innervation).

6. General patterns of innervation of internal organs.

7. Pathways for sensory, motor, parasympathetic and sympathetic conductors to internal organs.

8. Pathways for sensory, motor, sympathetic conductors to the soma.

9. Particular issues of innervation of a number of internal organs and soma.

10. General data on the formation of autonomic plexuses. Extraorgan and organ vegetative plexuses and their structural components.

11. Autonomic plexuses of the head.

12. Autonomic plexuses of the neck.

13. Autonomic plexuses of the thoracic cavity.

14. Autonomic plexuses of the abdominal cavity. Celiac plexus (sources of formation, sections, areas of innervation).

Set of drugs and tables

1. Table of the internal structure of the spinal cord.

2. Table on the anatomy of the autonomic nervous system

3. Table on the anatomy of the sympathetic division of the autonomic nervous system.

4. Table on the anatomy of the parasympathetic division of the autonomic nervous system.

5. Table of innervation of the salivary glands.

6. A corpse with dissected vessels and nerves.

7. Table on the anatomy of the abdominal aortic plexus.

8. Museum preparations (segment of the spinal cord with connections with the sympathetic trunk, borderline sympathetic trunk).

Show:

1. On the specified set of tables:

1) sympathetic centers (lateral intermediate nuclei of the C8 – L3 segments of the spinal cord);

2) sympathetic nodes:

a) paravertebral (1st order nodes or nodes of the sympathetic trunks);

b) prevertebral (second order nodes or intermediate nodes);

3) white communicating branches (branches of C8 – L3 spinal nerves);

4) gray communicating rami (branches of all spinal nerves);

5) sympathetic trunk (divisions, branches, areas of innervation):

a) cervical region:

The upper, middle and lower (stellate) nodes and their internodal branches (the internodal branch of the middle and lower cervical nodes bifurcates and is called the subclavian loop or Viessen's loop; the subclavian artery passes through it);

Ascending group of branches:

External carotid nerve (innervates large salivary glands, glands of the mucous membranes of the nasal and oral cavities, blood vessels, glands and smooth muscles of the scalp);

Internal carotid nerve (innervates the vessels of the brain, the lacrimal gland, the vessels of the eyeball and the dilator of the pupil);

The deep petrosal nerve (Vidian nerve), innervates the glands of the mucous membranes of the nasal and oral cavities, the lacrimal gland, and blood vessels);

Vertebral nerve (innervates the blood vessels of the brain);

Middle group of branches:

Laryngopharyngeal nerves (innervate the glands of the mucous membranes of the pharynx, larynx, thyroid and parathyroid glands, blood vessels);

Descending group of branches:

Branches to the thymus;

Upper, middle and lower cardiac nerves (innervate the conduction system of the heart and myocardium, coronary vessels);

Gray connecting branches (innervate the smooth muscles and glands of the skin of the shoulder girdle and upper extremities, provide trophic innervation of the skeletal muscles of these areas;

White connecting branch (at C 8);

b) thoracic region:

Thoracic nodes (10-12) and their internodal branches

Branches of the thoracic region and areas of their innervation:

White connecting branches (along the entire length of the department);

Gray connecting branches to the intercostal nerves (innervate smooth muscles, glands of the skin of the back, anterior-lateral walls of the thoracic and abdominal cavities, provide trophic innervation of the skeletal muscles of these areas;

Thoracic cardiac nerves (innervate the conduction system of the heart and myocardium, coronary vessels);

Pulmonary branches (innervate the glands and smooth muscles of the trachea, bronchial and alveolar trees, blood vessels);

Esophageal branches (innervate the glands of the entire length and smooth muscles of the lower 2/3 of the esophagus, blood vessels);

Aortic branches and branches to the thoracic lymphatic duct (innervate the smooth muscles of the wall);

Greater and lesser splanchnic nerves (contain both postganglionic sympathetic conductors of the nodes of the sympathetic trunk and preganglionic fibers to the prevertebral nodes; they pass through the chest cavity in transit and in the abdominal cavity take part in the formation of the abdominal aortic plexus);

c) lumbar region:

Lumbar nodes (3-4) and their internodal branches;

Branches of the lumbar region and areas of their innervation:

White communicating rami to the superior lumbar spinal nerves (L 1 – L 3);

Gray connecting branches to the lumbar spinal nerves (innervate smooth muscles, skin glands of the lumbar region, anterior abdominal wall, pubis and external genitalia, thighs, provide trophic innervation of the skeletal muscles of these areas;

Lumbar splanchnic nerves (contain both postganglionic sympathetic conductors of the nodes of the sympathetic trunk and preganglionic fibers to the prevertebral nodes; they take part in the formation of the plexus of the abdominal aorta);

d) sacral region:

lumbar nodes (3-4) and internodal branches;

Branches and areas of their innervation:

Gray connecting branches to the sacral spinal nerves S 1 – S 4 (innervate smooth muscles, glands of the skin of the gluteal region, perineum, lower limb, provide trophic innervation of the skeletal muscles of these areas;

Sacral splanchnic nerves (contain both postganglionic sympathetic conductors of the nodes of the sympathetic trunk and preganglionic fibers to the prevertebral nodes; they take part in the formation of the plexus of the abdominal aorta and its terminal branches);

e) coccygeal region (represented by 1 unpaired node, the internodal branches of which form the sacral loop - ansa sacralis); its gray connecting branches are part of the S 5 and Co 1 spinal nerves and innervate smooth muscles, skin glands, vessels of the coccyx and anus.

6) sympathetic postganglionic conductors (mainly follow to the object of innervation along the arterial wall with the formation of periarterial plexuses);

7) the course of sensitive conductors of a spinal nature to the internal organs (emerge from the trunk of the spinal nerves or as part of white or gray connecting branches and follow to the area of innervation along with sympathetic conductors);

2. On a corpse with dissected vessels and nerves and on museum preparations, show:

a) cervical sympathetic trunk (upper, middle and lower cervical nodes, internodal branches);

b) thoracic sympathetic trunk (white and gray connecting branches, internodal branches, large and small splanchnic nerves).

Sketch:

a) a diagram of the course of sympathetic conductors to the internal organs of the head, neck and chest cavity;

b) a diagram of the course of sympathetic conductors to the internal organs of the abdominal cavity;

c) diagram of the course of sympathetic conductors to the soma;

Questions for lecture material

1. Phylogenesis of the autonomic nervous system. The reason for the separation of the vegetative department, the sequence of appearance of its structural elements.

2. Ontogenesis of the autonomic nervous system. Origin of autonomic centers, ganglia. Establishing connections between autonomic centers, ganglia and innervation objects.

3 The division of the body into soma and viscera, the convention of this division.

4. General points and fundamental differences in the anatomy of somatic and

autonomic parts of the nervous system.

5. General data on the formation of autonomic plexuses. Extraorgan and organ vegetative plexuses and their structural components.

APPLICATION

I. PARTICULAR ISSUES OF INNERVATION OF INTERNAL

ORGANS AND SOMA

1. Innervation of the parotid salivary gland:

– auriculotemporal nerve (3rd branch of the trigeminal nerve, I neuron – cells of the gasserian ganglion);

I neuron - cells of the inferior salivary nucleus of the glossopharyngeal nerve, preganglionic conductors first pass as part of the trunk of the glossopharyngeal nerve, then pass into the tympanic nerve and, having passed the tympanic cavity, are called the lesser petrosal nerve;

II neuron - cells of the ear ganglion, the postganglionic conductors of which, as part of the auriculotemporal nerve, reach the parotid salivary gland, providing its secretory innervation (increased secretory activity);

postganglionics of which reach the gland from the external carotid nerve, providing its secretory innervation (decreasing the amount of saliva, increasing its viscosity), innervation of blood vessels;

2. Innervation of the sublingual and submandibular salivary glands:

a) afferent innervation pathway:

– lingual nerve (3rd branch of the trigeminal nerve, I neuron – cells of the gasserian ganglion);

Sensitive fibers of a spinal nature (I neuron - cells of the spinal ganglia);

b) the path of parasympathetic innervation:

Nerva,

preganglionic conductors first pass through the nerve trunk, then become part of the chorda tympani;

II neuron – cells of the submandibular (and non-permanent lingual) nodes, the postganglionic conductors of which reach the gland, providing their secretory innervation (increased secretory activity);

c) path of sympathetic innervation:

I neuron – cells of the lateral intermediate nuclei of the spinal cord;

II neuron – cells of the superior cervical ganglion of the sympathetic trunk,

postganglionics of which, as part of the external carotid nerve, provide their secretory innervation (decreasing the amount of saliva, increasing its viscosity), innervation of blood vessels;

3. Innervation of the eyeball:

a) afferent innervation pathways:

Overall sensitivity:

– long ciliary nerves (V pair, 1st branch, I neuron – gasserian ganglion cells);

sensory fibers of a spinal nature (I neuron - cells of the spinal ganglia);

Visual sensitivity – optic nerve (II pair);

b) the path of parasympathetic innervation:

I neuron - cells of the accessory nucleus of Yakubovich and the unpaired median nucleus of Pearl, preganglionic conductors pass in the trunk of the oculomotor nerve, pass into its lower branch, and ultimately form the oculomotor root;

II neuron – cells of the ciliary ganglion, the postganglionic conductors of which provide motor innervation to the ciliary muscle and the muscle that constricts the pupil;

c) path of sympathetic innervation:

the sympathetic trunk and along the internodal branches penetrate into its cervical region;

II neuron – cells of the superior cervical ganglion of the sympathetic trunk,

postganglionics of which, as part of the internal carotid nerve, innervate the pupillary dilator and the vessels of the eyeball;

4. Innervation of the external muscles of the eye:

a) paths of afferent (proprioceptive) innervation:

optic nerve (V pair, 1st branch, I neuron - Gasserian ganglion cells);

Sensitive fibers of a spinal nature (I neuron - cells of the spinal ganglia);

b) paths of motor innervation: the muscle that lifts the upper eyelid, the superior, medial and inferior rectus muscles, the inferior oblique muscle are innervated by the superior and inferior branches of the oculomotor nerve (III pair); - the superior oblique muscle is innervated by the trochlear nerve (IV pair); - lateral rectus the muscle is innervated by the abducens nerve (VI pair);

c) path of sympathetic innervation:

I neuron – cells of the lateral intermediate nuclei of the spinal cord; preganglionic conductors enter the sympathetic trunk along the white connecting branches and penetrate into its cervical region through the internodal branches;

II neuron – cells of the upper cervical ganglion of the sympathetic trunk, the postganglionics of which, as part of the internal carotid nerve, innervate the muscles of the oculomotor groups (trophic innervation) and their vessels;

5. Innervation of the lacrimal gland:

a) afferent innervation pathway:

– lacrimal nerve (V pair, 1st branch, I neuron – cells of the gasserian ganglion);

Sensitive fibers of a spinal nature (I neuron - cells of the spinal ganglia);

b) the path of parasympathetic innervation:

I neuron – cells of the superior salivary nucleus of the facial

(intermediate) nerve, preganglionic conductors first pass as part of the nerve trunk, then form the greater petrosal nerve;

II neuron – cells of the pterygopalatine ganglion, the postganglionic conductors of which reach the gland as part of the orbital nerves, providing its secretory innervation (increasing the secretory activity of the gland);

c) path of sympathetic innervation:

I neuron – cells of the lateral intermediate nuclei of the spinal cord;

preganglionic conductors along the white communicating branches enter into

the sympathetic trunk and along the internodal branches penetrate into its cervical region;

II neuron - cells of the upper cervical ganglion of the sympathetic trunk, the postganglionics of which, as part of the internal carotid and deep petrosal nerves (departs from the upper cervical ganglion), provide its secretory innervation (reduction or delay of tear secretion), innervation of blood vessels;

6. Innervation of the tongue:

a) afferent innervation pathway:

General Sensitivity Path:

Lingual nerve (anterior 2/3 of the tongue, V pair, 3rd branch, I neuron - gasserian ganglion cells);

Lingual branch of the glossopharyngeal nerve (posterior 1/3 of the tongue, IX pair,

Superior laryngeal nerve (root of the tongue, X pair, I neuron - cells of the upper and lower nodes of the nerve);

Pathway of taste sensitivity:

The chorda tympanum of the intermediate nerve (anterior 2/3 of the tongue, VII pair, I neuron - cells of the genu ganglion);

Lingual branch of the glossopharyngeal nerve (posterior 1/3 of the tongue, IX pair,

I neuron - cells of the superior and inferior ganglia of the nerve);

Superior laryngeal nerve vagus nerve (root of tongue, X pair,

I neuron – cells of the upper and lower nodes of the nerve);

b) the path of motor innervation – hypoglossal nerve (XII pair);

I neuron – cells of the superior salivary nucleus of the facial

(intermediate) nerve, preganglionic conductors first pass as part of the nerve trunk, then pass into the string of tympani;

II neuron – cells of the submandibular (and non-permanent lingual) nodes, the postganglionic conductors of which reach the gland of the tongue, providing their secretory innervation (increased secretion);

I neuron – cells of the lateral intermediate nuclei of the spinal cord;

preganglionic conductors enter the sympathetic trunk along the white connecting branches and penetrate into its cervical region through the internodal branches;

II neuron – cells of the superior cervical ganglion of the sympathetic trunk,

postganglionics of which, as part of the external carotid nerve, provide secretory innervation of the glands of the tongue (inhibition of secretion), blood vessels, and trophic innervation of muscles;

7. Innervation of the heart:

a) afferent innervation pathway:

upper cervical cardiac nerve (branch of the cervical vagus nerve, X pair, I neuron - cells of the upper and lower nodes of the nerve);

Inferior cervical cardiac nerve (branch of recurrent laryngeal nerve

thoracic vagus nerve, X pair, I neuron - cells of the superior and inferior nodes of the nerve);

Thoracic cardiac nerves (branches of the thoracic vagus nerve,

I neuron – cells of the upper and lower nodes of the nerve);

Sensitive fibers of a spinal nature (I neuron - cells of the spinal ganglia);

b) the path of parasympathetic innervation:

the conductors pass as part of the nerve trunk, then pass into the upper and lower cardiac nerves, thoracic cardiac nerves;

II neuron - cells of the intramural nodes of the heart, the postganglionics of which end on the elements of its conduction system (inhibition and suppression of cardiac activity - decreased frequency and strength of heart contractions, narrowing of the coronary arteries);

c) path of sympathetic innervation:

I neuron – cells of the lateral intermediate nuclei of the spinal cord;

preganglionic conductors along the white communicating branches enter into

the sympathetic trunk and along the internodal branches spread to its cervical and thoracic regions;

II neuron – cells of the cervical and thoracic ganglia of the sympathetic trunk,

postganglionics of which, as part of the upper and lower cardiac nerves, thoracic cardiac nerves, end on the myocardium, elements of the conduction system of the heart (increased frequency and force of heart contractions), cardiac vessels (dilation of the coronary arteries);

8. Innervation of the larynx:

a) afferent innervation pathway:

superior laryngeal nerve vagus nerve, distributed in the upper

half of the larynx (Hpara, I neuron - cells of the upper and lower ganglia of the nerve);

The lower laryngeal nerve is distributed in the lower half of the larynx (a branch of the recurrent laryngeal nerve of the vagus nerve, Xpara, I neuron - cells of the upper and lower nodes of the nerve);

ganglia);

The cricothyroid muscle is innervated by the superior laryngeal nerve;

The posterior and lateral cricoarytenoid, thyroarytenoid, transverse and oblique arytenoid, thyroepiglottic and vocal muscles are innervated by the inferior laryngeal nerve;

c) the path of parasympathetic innervation:

I neuron – cells of the dorsal nucleus of the vagus nerve (X pair), preganglionic conductors pass as part of the nerve trunk, then pass into the laryngeal branches;

II neuron - cells of the intramural nodes of the larynx, the postganglionics of which innervate the glands of its mucous membrane (increased secretion);

d) path of sympathetic innervation:

II neuron – cells of the cervical nodes of the sympathetic trunk, the postganglionics of which innervate the glands of the mucous membrane of the larynx (inhibition of secretion), blood vessels and provide trophic innervation to the muscles.

9. Innervation of the trachea and lungs:

a) afferent innervation pathway:

Tracheal and pulmonary branches of the thoracic vagus nerve (X pair,

I neuron – cells of the upper and lower nodes of the nerve);

Sensitive fibers of a spinal nature (I neuron - spinal cells

ganglia);

Note: The parietal pleura is innervated by the upper 6 intercostal nerves.

b) the path of parasympathetic innervation:

I neuron – cells of the dorsal nucleus of the vagus nerve (X pair),

preganglionic conductors pass as part of the nerve trunk, then pass into the tracheal and pulmonary branches;

II neuron - cells of the intramural nodes of the trachea and lungs, the postganglionics of which innervate the tracheal glands of the bronchial and alveolar trees (increased mucus secretion), their smooth muscles (narrowing of the lumen of the bronchi and bronchioles);

c) path of sympathetic innervation:

I neuron – cells of the lateral intermediate nuclei of the spinal cord; preganglionic conductors along the white communicating branches enter into

the sympathetic trunk and along the internodal branches spread to its thoracic region;

II neuron – cells of the thoracic nodes of the sympathetic trunk, the postganglionics of which innervate the glands of the trachea, bronchial and alveolar trees (inhibition of secretion), their smooth muscles (expansion of the lumen of the bronchi and bronchioles), blood vessels (vasoconstriction);

10. Innervation of the soft palate:

a) afferent innervation pathway:

The greater and lesser palatine nerves of the second branch of the trigeminal nerve (V pair, I neuron - cells of the gasserian ganglion);

b) motor pathway of innervation:

The tensor velum palatine is innervated by the trigeminal nerve (V pair, 3rd branch);

The levator velum palatini, palatoglossus, velopharyngeal and uvula muscles are innervated by the pharyngeal branches of the vagus nerve (X pair);

c) the path of parasympathetic innervation:

II neuron – cells of the intramural nodes of the soft palate, the postganglionics of which innervate the glands of its mucous membrane (increased secretory activity);

d) path of sympathetic innervation:

I neuron – cells of the lateral intermediate nuclei of the spinal cord; preganglionic conductors along the white communicating branches enter into

the sympathetic trunk and along the internodal branches spread to its cervical region;

II neuron – cells of the cervical nodes of the sympathetic trunk, the postganglionics of which innervate the glands of the soft palate (inhibition of secretion), blood vessels and provide trophic innervation to the muscles.

11. Innervation of the pharynx:

a) afferent innervation pathway:

Pharyngeal branches of the glossopharyngeal nerve (IX pair, I neuron - cells of the upper

and inferior ganglia of the nerve);

Pharyngeal branches of the vagus nerve (Hpara, I neuron - cells of the superior and inferior ganglia of the nerve);

Sensitive fibers of a spinal nature (I neuron - spinal cells

ganglia);

b) motor pathway of innervation:

The stylopharyngeal muscle is innervated by the glossopharyngeal nerve (IX pair);

The superior, middle and inferior constrictors are innervated by the vagus nerve (X pair),

c) the path of parasympathetic innervation:

I neuron – cells of the dorsal nucleus of the vagus nerve (X pair), preganglionic conductors pass as part of the nerve trunk, then pass into the pharyngeal branches;

II neuron - cells of the intramural nodes of the pharynx, the postganglionics of which innervate the glands of its mucous membrane (increased secretion);

d) path of sympathetic innervation:

I neuron – cells of the lateral intermediate nuclei of the spinal cord; preganglionic conductors along the white connecting branches enter the sympathetic trunk and spread through the internodal branches to its cervical region;

II neuron - cells of the cervical nodes of the sympathetic trunk, the postganglionics of which innervate the glands of the pharyngeal mucosa (inhibition of secretion), blood vessels and provide trophic innervation to the muscles.

12. Innervation of the esophagus (cervical and thoracic regions):

a) afferent innervation pathway:

Esophageal branches of the recurrent laryngeal nerve of the vagus nerve X pair, I neuron - cells of the superior and inferior nodes of the nerve);

Esophageal branches of the thoracic vagus nerve ((Xpara, I neuron - cells of the upper and lower nodes of the nerve);

Sensitive fibers of a spinal nature (I neuron - cells of the spinal ganglia);

b) motor pathway of innervation:

The esophageal branches of the recurrent laryngeal nerve of the vagus nerve innervate the voluntary muscles of the upper 1/3 of the organ;

c) the path of parasympathetic innervation:

I neuron – cells of the dorsal nucleus of the vagus nerve (X pair), preganglionic conductors pass as part of the nerve trunk, then pass into the composition of its esophageal branches;

II neuron - cells of the intramural nodes of the esophagus, the postganglionics of which innervate the glands of the mucous membrane throughout the organ (increased secretion) and the smooth muscles of the middle and lower sections (increased contractions);

d) path of sympathetic innervation:

II neuron - cells of the thoracic nodes of the sympathetic trunk, the postganglionics of which innervate the glands of the mucous membrane of the esophagus (inhibition of secretion), blood vessels and involuntary muscles of the middle and lower parts of the organ (weakening of contractions).

13. Innervation of the abdominal esophagus, stomach, small and large intestine (to the descending colon), pancreas, liver, kidneys and ureters:

a) afferent innervation pathway:

Branches of the abdominal vagus nerve (X pair, I neuron - cells of the upper and lower nodes of the nerve);

Sensitive fibers of the spinal nature of the large, small and lumbar splanchnic nerves (I neuron - cells of the spinal ganglia);

Note: the parietal peritoneum is innervated by the lower 6 intercostal nerves.

c) the path of parasympathetic innervation:

I neuron - cells of the dorsal nucleus of the vagus nerve (X pair), preganglionic conductors pass as part of the nerve trunk, then pass into the composition of its abdominal branches (the plexus of the abdominal aorta passes through in transit - celiac, aortic-renal, superior and inferior mesenteric plexuses);

II neuron - cells of the intramural nodes of these organs, the postganglionics of which innervate the glands of the mucous membranes (increased secretion) and smooth muscles (increased peristalsis, relaxation of involuntary intestinal sphincters, bile ducts), parenchyma;

d) path of sympathetic innervation:

II neurons:

– to a lesser extent, these are the cells of the thoracic and lumbar nodes of the sympathetic trunk, the postganglionics of which enter the plexus of the abdominal aorta and pass through it in transit;

To a greater extent, these are the cells of the prevertebral nodes (celiac, aortic-renal, superior and inferior mesenteric), on which the switch to the second sympathetic neuron occurs; postganglionics of all these nodes (I and II order) innervate the glands of the mucous membrane (decreased secretory activity) and smooth muscles (suppression of motor activity, reduction of involuntary intestinal sphincters, bile ducts), parenchyma, vessels of these organs (vasoconstriction);

14. Innervation of the descending and sigmoid colon, rectum, bladder, uterus and its appendages, vas deferens, seminal vesicles, prostate gland:

a) afferent innervation pathway:

Sensitive fibers of the spinal nature of the lumbar and sacral splanchnic nerves (I neuron - cells of the spinal ganglia);

Note: for this group of organs there is no vagal canal of afferent innervation.

c) the path of parasympathetic innervation:

I neuron - cells of the lateral intermediate nuclei of the spinal cord of segments S 2 - S 4, preganglionic conductors pass as part of the anterior branches of the sacral spinal nerves, in the pelvic cavity they leave them under the name of the pelvic splanchnic nerves, after which the sections of the abdominal aortic plexus (superior and lower hypogastric);

II neuron - cells of the intramural nodes of these organs (increased secretion) and smooth muscles (increased intestinal motility, relaxation of involuntary sphincters of the intestine and bladder, contraction of the bladder muscles), dilation of the vessels of the cavernous bodies of the penis;

d) path of sympathetic innervation:

II neurons:

– to a lesser extent, these are the cells of the lumbar and sacral nodes of the sympathetic trunk, the postganglionics of which enter the plexus of the abdominal aorta and pass through it in transit;

To a greater extent, these are the cells of the prevertebral nodes (superior and inferior hypogastric), on which the switch to the second sympathetic neuron occurs; The postganglionics of all these nodes (I and II order) innervate the glands of the mucous membrane (decreased secretion) and smooth muscles (suppression of intestinal motility, contraction of involuntary sphincters of the intestine and bladder, relaxation of the bladder muscles, contraction of the muscles of the uterus), the vessels of these organs (vasoconstriction );

15. Innervation of blood vessels:

a) afferent innervation pathway:

Afferent fibers of the V, VII, IX, X cranial nerves (I neuron - cells of the gasserian ganglion of the trigeminal nerve, the genu ganglion of the facial nerve, the superior and inferior ganglia of the glossopharyngeal and vagus nerves);

Sensitive fibers of a spinal nature (I neuron - cells of all spinal ganglia);

II neurons - cells of the sympathetic trunk (paravertebral nodes) and cells of the prevertebral ganglia of the abdominal cavity, postganglionics of all these nodes innervate the smooth muscles of arteries and veins, providing mainly vasoconstrictor, but in some cases also vasodilator effects.

c) the path of parasympathetic innervation (not recognized by all authors):

I neuron - autonomic nuclei of the cranial nerves and lateral intermediate nuclei of the spinal cord of segments S 2 - S 4, preganglionic conductors pass through the III, VII, IX, X pairs of cranial nerves and the anterior branches of the sacral spinal nerves;

II neuron - cells of intramural vascular nodes, the postganglionics of which innervate smooth muscles, providing vasodilatory effects;

16. Innervation of the soma:

a) afferent innervation pathway - afferent fibers of the spinal nerves (I neuron - cells of all spinal ganglia);

b) path of sympathetic innervation:

II neurons - cells of all nodes of the sympathetic trunk (paravertebral nodes), postganglionics return to each spinal nerve along the gray connecting branches and along its anterior, posterior and meningeal branches reach the elements of the soma, where they innervate blood vessels, sweat and sebaceous glands of the skin, smooth muscles of the skin (muscles that raise the hair), provide trophic innervation to skeletal muscles.

Related information.