Innervation of the lacrimal and salivary glands

The afferent pathway for the lacrimal gland is n. lacrimalis (branch of n. ophthalmicus from n. trigemini), for the submandibular and sublingual - n. lingualis (branch of n. mandibularis from n. trigemini) and chorda tympani (branch of n. intermedius), for the parotid - n. auriculotemporal and n. glossopharyngeus.

Efferent parasympathetic innervation of the lacrimal gland. The center lies in the upper section medulla oblongata and is associated with the nucleus of the intermediate nerve (nucleus salivatorius superior). Preganglionic fibers are part of n. intermedius, then n. petrosus major to ganglion pterygopalatinum. This is where the postganglionic fibers begin, which are part of n. maxillaris and further its branches, n. zygoma ticus, through connections with n. lacrimalis reach the lacrimal gland.

Efferent parasympathetic innervation of the submandibular and sublingual glands. Preganglionic fibers come from the nucleus salivatorius superior as part of n. intermedius, then chorda tympani and n. lingualis to the ganglion submandibulare, from where the spinal glionic fibers that reach the glands begin.

Efferent parasympathetic innervation parotid gland. Preganglionic fibers come from the nucleus salivatorius inferior as part of n. glossopharyngeus, then n. tympanicus, n. petrosus minor to ganglion oticum. This is where the postganglionic fibers begin, going to the gland as part of n. auriculotemporalis. Function: increased secretion of the lacrimal and named salivary glands; dilation of gland vessels.

Efferent sympathetic innervation of all these glands. Preganglionic fibers begin in the lateral horns of the upper thoracic segments of the spinal cord and end in the superior cervical ganglion of the sympathetic trunk. Postganglionic fibers begin in the named node and reach the lacrimal gland as part of the plexus caroticus internus, to the parotid gland as part of the plexus caroticus externus, and to the submandibular and sublingual glands through the plexus caroticus externus and then through the plexus facialis.

There is nothing anywhere about the minor salivary glands, but! they are located in the oral mucosa, which is innervated by the branches of the inferior alveolar nerve ( n. alveolaris inferior) (- mandibular nerve - trigeminal nerve), and since the mucous membrane is innervated by the trigeminal nerve, like all other glands, further information will flow in the same way as other structures.

Ticket 48.

1. Osteofibrous canals (flexor and extensor retinaculum, carpal canals), sheaths (synovial) of muscle tendons upper limb. Synovial bursae. EXTENSORS

Subcutaneous fatty tissue the posterior region of the wrist is loose, moderately developed. Edema fluid easily accumulates in it. The proper fascia of the dorsal surface of the wrist is thickened and forms the extensor retinaculum, retinaculum musculorum extensoram. Under it there are 6 bone-fibrous canals formed as a result of the departure from the retinaculum mm. extensoram fascial septa attached to the bones and ligaments of the wrist. The canals contain the tendons of the extensor muscles of the wrist and fingers, surrounded by synovial sheaths.

Starting from the medial (ulnar) side, these are the following channels: 1. Canal of the extensor carpi ulnaris, m. extensor carpi ulnaris. Its synovial vagina extends from the head ulna before the tendon attaches to the base of the fifth metacarpal bone. 2. Canal of the extensor of the little finger, m. extensor digiti minimi. The synovial sheath of the extensor of the little finger is located proximally at the level of the distal radioulnar joint, and distally - below the middle of the fifth metacarpal bone. 3. Tendon channel m. extensor digitorum and m. extensor indicis, enclosed in a triangular synovial vagina with the base facing the fingers 4. Canal m. extensor pollicis longus. The tendon of this muscle, located in its own synovial vagina, vagina tendinis m. extensoris pollicis longi, turns at an acute angle to the lateral side and crosses the radial extensor tendons of the hand in front, mm. extensores carpi radiales longus et brevis. 5. Osteofibrous canal of the radial extensors of the hand, mm. extensores carpi longus et brevis, is located lateral and deeper than the previous one. The synovial sheaths of the tendons of these muscles can communicate with the cavity of the wrist joint. 6. Channel m. abductor pollicis longus and m. extensor pollicis brevis is located on the lateral surface of the styloid process radius.

FLEXORS Synovial sheaths on the palmar surface contain: the first - the tendons of the superficial and deep flexor of the fingers, the second - the long flexor of the first finger. Both synovial sheaths are located in the carpal tunnel (canalis carpalis), which is limited by the bones of the wrist and the retinaculum flexorum. At the top, the synovial sheaths extend 1-1.5 cm above the retinaculum flexorum. Below, the first sheath forms an expansion in the area of ​​the tendons of the II, III, IV fingers, ending in the middle of the metacarpal bones. The synovial sheath surrounding the flexor tendon of the fifth finger starts from the level of the wrist joint and reaches distal phalanx V finger. The II, III and IV fingers have independent synovial sheaths for the tendons of the superficial and deep flexor of the fingers. The second synovial sheath for the tendon of the long flexor of the first finger extends to the distal phalanx. Synovial bursa (lat. bursa synovialis) - a small flattened cavity lined synovial membrane, delimited from surrounding tissues by a capsule and filled with synovial fluid. By location, subcutaneous, subfascial, subtendinous and axillary synovial bursae are distinguished.1 Synovial bursae of the upper limb, bursae membri superioris.2Trapezius muscle subtendinous bursa, b. subtendinea m.trapezii. Localized between the ascending part of m. trapezius and the spine of the scapula. 3 Acromial subcutaneous bursa, b. subcutanea acromialis 4Subacromial bursa, b. subacromialis. Located under the acromion and deltoid muscle on the capsule shoulder joint. 5 Subdeltoid bursa, b. subdeltoidea. Located between the deltoid muscle and the capsule of the shoulder joint. Sometimes connected to the subacromial bursa 6Bursa of the coracobrachialis muscle, b. m.coracobrachialis. It is localized below the apex of the coracoid process between the tendons of the subscapularis and coracobrachialis muscles. 7 Subtendinous bursa of the infraspinatus muscle, b. subtendinea m. infraspinati. Located between the infraspinatus tendon and the capsule of the shoulder joint. 8 Subtendinous bursa of the subscapularis muscle, b. subtendinea m. subscapularis. Located between the tendon of the subscapularis muscle and the capsule of the shoulder joint. Connects to the articular cavity. 9Tendinous bursa of the teres major muscle, b. subtendinea m. teretis majoris. Located between the tendon of the corresponding muscle and the humerus. 10The subtendinous bursa of the latissimus dorsi muscle, b. subtendinea m. latissimi dorsi. Located between the tendons of the teres major muscle and the latissimus dorsi muscle11 Ulnar subcutaneous bursa, b.subcutanea olecrani. Located between the olecranon and the skin. 12 Ulnar intratendinous bursa, b.intratendinea olecrani. Located inside the triceps brachii tendon, near the olecranon process. 13 Subtendinous bursa of the triceps brachii muscle, b. subtendinea m. tricipitis brachii. It is located between the tendon of the muscle of the same name and the olecranon process. 14Biceps-radial bursa, b. bicipitoradialis. Localized between the biceps tendon and the radial tuberosity. 15 Interosseous ulnar bursa, b.cubitalis interossea. Located between the biceps tendon and the ulna or oblique chord.

TO major salivary glands (glandulae salivariae majores) include paired parotid, sublingual and submandibular glands.

The large salivary glands belong to the parenchymal organs, which include:

parenchyma- specialized (secretory) part of the gland, represented by the acinar section containing secretory cells where secretion is produced. The salivary glands include mucous cells that secrete a thick mucous secretion, and serous cells that secrete liquid, watery, so-called serous or protein saliva. The secretion produced in the glands is delivered through the system of excretory ducts to the surface of the mucous membrane in different departments oral cavity.

stroma- a complex of connective tissue structures that form the internal frame of the organ and contribute to the formation of lobules and lobes; in the layers of connective tissue there are vessels and nerves leading to the acinar cells.

Parotid gland

Parotid gland (glandula parotidea) is the largest of the salivary glands, which is located downward and anterior to auricle, at the posterior edge of the masticatory muscle. Here it is easily accessible for palpation.

Sometimes there may also be an accessory parotid gland (glandula parotidea accessoria), located on the surface of the masticatory muscle near the parotid duct. The parotid gland is a complex multilobulated alveolar gland consisting of serous cells that produce serous (protein) saliva. It distinguishes between the superficial part (pars superficialis) and the deep part (pars profunda).

The superficial part of the gland has a chewing process and is located on the branch lower jaw and on the masticatory muscle. Sometimes there is also a superior process adjacent to the cartilaginous portion of the external auditory canal. The deep part often has pharyngeal and posterior processes. It is located in the mandibular fossa (fossa retromandibularis), where it is adjacent to the temporomandibular joint, mastoid process temporal bone and some neck muscles.

The parotid gland is covered by the parotid fascia, which forms the capsule of the gland. The capsule consists of superficial and deep layers covering the gland from the outside and inside. It is closely connected to the gland by connective tissue bridges that continue into septa that separate the lobules of the gland from each other. The deep layer of the capsule in the area of ​​the pharyngeal process is sometimes absent, which creates conditions for the purulent process to spread into the peripharyngeal space during parotitis.

Parotid duct(ductus parotideus), or Stenon's duct The name "Stenon's duct" is derived from the name of the anatomist who described it. Such anatomical terms are called eponyms. Eponyms are often used in clinical practice along with nomenclature anatomical terms., is formed by the fusion of interlobar ducts and reaches a diameter of 2 mm. Leaving the gland at its anterior edge, it lies on masticatory muscle 1 cm below the zygomatic arch, pierces the buccal muscle and opens on the mucous membrane of the cheek into the vestibule of the mouth at the level of the 1st-2nd upper molars. The accessory parotid gland is usually located above the parotid duct, into which its own duct flows.

Passes through the thickness of the parotid gland external carotid artery And submandibular vein. Inside the gland, the external carotid artery divides into two terminal branches - maxillary And superficial temporal artery.

Also passes through the parotid gland facial nerve . In it, it is divided into a number of branches radiating from the area of ​​the earlobe to facial muscles faces.

Blood supply parotid salivary gland is carried out by branches outdoor carotid artery (a. carotis externa), among which posterior auricular artery(a. auricularis posterior), passing obliquely backwards over top edge posterior belly of the digastric muscle, transverse artery of the face(a. transversa faciei) and zygomaticoorbital artery(a. zygomaticoorbitalis), extending from superficial temporal artery (a. temporalis superficialis), as well as deep auricular artery(a. auricularis profunda), extending from maxillary artery (a. maxillaris) (see Fig. 10). The excretory duct of the parotid gland is supplied with blood from the transverse artery of the face. The arteries of the parotid gland have numerous anastomoses with each other and with the arteries of nearby organs and tissues.

Venous drainage provided by the veins accompanying the excretory ducts of the gland. Merging, they form parotid veins Ezes (vv. parotideae), carrying blood into mandibular(v. retromandibularis) and facial veins(v. facialis) and further into internal jugular vein(v. jugularis interna).

On the way to the mandibular vein, blood from the upper part of the gland also flows into transverse vein of the face(v. transversa faciei), from its middle and lower part - in masticatory veins(vv. maxillares) and pterygoid plexus(plexus pterygoideus), from the anterior part of the gland - in anterior auricular veins(vv. auriculares anteriores). From the postauricular part of the gland, venous blood flows into posterior auricular vein(v. auricularis posterior), sometimes - in occipital veins(vv. occipitales) and further to outdoor jugular vein (v. jugularis externa).

Lymphatic drainage carried out mainly in deep parotid nodes(nodi parotidei profundi), which includes preauricular, inferior auricular and intraglandular nodes,

and also in superficial parotid nodes(nodi parotidei superficiales). Of these, lymph is directed to superficial And lateral deep cervical ganglia.

Innervation parotid gland is carried out by the parotid branches auriculotemporal nerve(n. auriculotemporalis), extending from mandibular nerve(n. mandibularis - III branch of n. trigeminus). The parotid branches (rr. parotidei) include the sensory ones, the following in the composition trigeminal nerve , and autonomic nerve fibers.

The autonomic innervation of the parotid gland is carried out by parasympathetic postganglionic nerve fibers arising from ear node(ganglion oticum), located on the medial surface of the mandibular nerve under the foramen ovale, and sympathetic postganglionic nerve fibers extending from upper cervical node(ganglion cervicale superius).

Preganglionic parasympathetic nerve fibers originate from inferior salivary nucleus(nucl. salivatorius inf.), located in the medulla oblongata; then in the composition glossopharyngeal nerve(n. glossopharyngeus - IX pair of cranial nerves) and its branches (n. tympanicus, n. petrosus minor) reach ear node(ganglion oticum). From the ear ganglion, postganglionic nerve fibers follow branches in the parotid gland auriculotemporal nerve.

Parasympathetic nerve fibers stimulate the secretion of the gland and dilate its blood vessels.

Preganglionic sympathetic nerve fibers begin from the autonomic nuclei of the upper thoracic segments of the spinal cord and, as part of the sympathetic trunk, reach the superior cervical ganglion.

Sympathetic postganglionic nerve fibers come from the superior cervical ganglion and approach the parotid gland as part of plexus of external carotid artery(plexus caroticus externus) along the branches of the external carotid artery supplying blood to the gland. Sympathetic innervation has a constricting effect on blood vessels and inhibits the secretion of the gland.

Saliva secretion is controlled by the autonomic nervous system. Parasympathetic and sympathetic nerves are sent to the salivary glands and reach them by following different routes. Axons inside the glands of various origins arranged in the form of bundles.
Nerve fibers running in the stroma of the glands together with the vessels are directed to the smooth myocytes of the arterioles, the secretory and myoepithelial cells of the coiceal sections, as well as the cells of the intercalary and striated sections. The axons, losing their sheath of Schwann cells, penetrate the basement membrane and are located between the secretory cells of the terminal sections, ending in terminal varicose veins containing vesicles and mitochondria (hypolemmal neuroeffector contact). Some axons do not penetrate the basement membrane, forming varicose veins close to secretory cells (epilemmal neuroeffector contact). The fibers innervating the ducts are located predominantly outside the epithelium. The blood vessels of the salivary glands are innervated by sympathetic and parasympathetic axons.
“Classical” neurotransmitters (acetylcholine in parasympathetic and norepinephrine in sympathetic axons) accumulate in small vesicles. Immunohistochemically, a variety of neuropeptide mediators were found in the nerve fibers of the salivary glands, which accumulate in large vesicles with a dense center - substance P, calcitonin gene-related peptide (CABP), vasoactive intestinal peptide (VIP), C-edge peptide of neuropeptide Y (CPON), histidine-methionine peptide (PHM).
The most numerous fibers contain VIP, PGM, CPON. They are located around the end sections, penetrating into them, entwining the excretory ducts and small vessels. Fibers containing PSKG and substance P are much less common. It is assumed that peptidergic fibers are involved in the regulation of blood flow and secretion.
Afferent fibers were also found, which were most numerous around the large ducts; their endings penetrate the basement membrane and are located among the epithelial cells. Substance P-containing unmyelinated and thin myelinated fibers carrying nociceptive signals are located around the terminal sections, blood vessels n excretory ducts.
Nerves have at least four types of effects on the glandular cells of the salivary glands: hydrokinetic (water mobilization), proteokinetic (protein secretion), synthetic (increased synthesis) and trophic (maintenance normal structure and functions). In addition to affecting glandular cells, nerve stimulation causes contraction of myoepithelial cells, as well as changes vascular bed(vasomotor effect).
Stimulation of parasympathetic nerve fibers results in the secretion of a significant volume of watery saliva with low protein content and high concentrations of electrolytes. Stimulation of sympathetic nerve fibers causes the secretion of small amounts of viscous saliva with a high mucus content.

Most researchers indicate that the salivary glands are not fully formed at the time of birth; their differentiation is completed mainly by 6 months - 2 years of life, but morphogenesis continues until 16-20 years. At the same time, the nature of the secretion produced may also change: for example, in the parotid gland, during the first years of life, a mucous secretion is produced, which only becomes serous from the 3rd year. After birth, the synthesis of lysozyme and lactoferrin by epithelial cells decreases, but the production of the secretory component progressively increases. At the same time, in the stroma of the gland the number of plasma cells that produce predominantly IgA increases.
After 40 years, the phenomena of age-related involution of glands are observed for the first time. This process intensifies in the elderly and old age, which is manifested by changes in both the terminal sections and the excretory ducts. The glands, which have a relatively monomorphic structure in youth, are characterized by progressive heteromorphy with age.
With age, the terminal sections acquire greater differences in size, shape and tinctorial properties. The size of the cells of the terminal sections and the content of secretory granules in them decrease, and the activity of their lysosomal apparatus increases, which is consistent with the often detected patterns of lysosomal destruction of secretory granules - crinophagy. The relative volume occupied by the cells of the terminal sections in large and small glands decreases by 1.5-2 times with aging. Some of the terminal sections atrophy and are replaced by connective tissue, which grows both between the lobules and inside the lobules. Predominantly the protein terminal sections are subject to reduction; mucous sections, on the contrary, increase in volume and accumulate secretions. By the age of 80 (as in early childhood), predominantly mucous cells are found in the parotid gland.
Oncocytes. In the salivary glands of people over 30 years old, special epithelial cells are often found - oncocytes, which are rarely detected in more at a young age and are present in almost 100% of glands in people over 70 years of age. These cells are found singly or in groups, often in the center of the lobules, both in the terminal sections and in the striated and intercalated ducts. They are characterized large sizes, sharply oxyphilic granular cytoplasm, vesicular or pyknotic nucleus (binuclear cells are also found). At the electron microscopic level, a distinctive feature of oncocytes is the presence in their

toplasma huge amount mitochondria, filling most of its volume.
The functional role of oncocytes in the salivary glands, as well as in some other organs (thyroid and parathyroid glands) has not been determined. The traditional view of oncocytes as degeneratively changed elements is not consistent with their ultrastructural characteristics and their active participation in the metabolism of biogenic amines. The origin of these cells is also a matter of debate. According to a number of authors, they arise directly from the cells of the terminal sections and excretory ducts due to their changes. It is also possible that they are formed as a result of a peculiar change in the course of differentiation of the cambial elements of the gland epithelium. Oncocytes of the salivary glands can give rise to special tumors of the organ - oncocytomas.
Excretory ducts. The volume occupied by the striated sections decreases with aging, while the interlobular excretory ducts expand unevenly, and accumulations of compacted material are often found in them. The latter are usually oxyphilic colored, may have a layered structure and contain calcium salts. The formation of such small calcified bodies (calculi) is not considered an indicator pathological processes in the glands, however, the formation of large stones (diameter from several millimeters to several centimeters), causing disturbances in the outflow of saliva, is a leading sign of a disease called salivary stone disease, or sialolithiasis.
The stromal component with aging is characterized by an increase in fiber content (fibrosis). The main changes in this case are due to an increase in volume and a denser arrangement of collagen fibers, but at the same time a thickening of elastic fibers is also observed.
In the interlobular layers, the number of adipocytes increases, which can subsequently appear in the lobules of the glands, replacing the terminal sections. This process is most pronounced in the parotid gland. In the latter, for example, with aging, up to 50% of the terminal sections are replaced by adipose tissue. In places, often along the excretory ducts and subepithelial, accumulations of lymphoid tissue are detected. These processes occur in both large and small salivary glands.

Sympathetic nervous system

Its function is adaptive trophic (changes the level of metabolism in organs depending on the function they perform in certain environmental conditions).

It is divided into a central and peripheral section.

The central section is thoracolumbar, as it is located in the lateral horns of the spinal cord from the 8th cervical to the 3rd lumbar segment of the spinal cord.

These nuclei are called nucleus intermediolateralis.

Peripheral department.

This includes:

1) rami communicantes albi et grisei

2) nodes of 1st and 2nd order

3) plexuses

1) Nodes of the 1st order are ganglia trunci sympathici or nodes of the sympathetic trunks, which run from the base of the skull to the coccyx. These nodes are divided into groups: cervical, thoracic, lumbar and sacral.

Cervical - in these nodes there is a switching of nerve fibers for the organs of the head, neck and heart. There are 3 cervical nodes: ganglion cervicale superius, medium, inferius.

Thoracic - there are only 12 of them. Nerve fibers are switched in them to innervate the organs of the thoracic cavity.

Nodes of the 2nd order - are located in abdominal cavity in those places where unpaired visceral arteries depart from the aorta, these include 2 celiac nodes (ganglia celiaci), 1 superior mesenteric node (ganglion mesentericum superius),

1 inferior mesenteric (mesentericum inferius)

Both celiac and superior mesenteric nodes belong to the solar plexus and are needed for the innervation of the abdominal organs.

The inferior mesenteric node is needed to innervate the pelvic organs.

2) Rami communicantes albi - connect spinal nerves with the nodes of the sympathetic trunk and are part of the preganglionic fibers.

There are a total of 16 pairs of white connecting branches.

Rami communicantes grisei - connect nodes with nerves, they are part of postganglionic fibers, there are 31 pairs of them. They innervate the soma and belong to the somatic part of the sympathetic nervous system.

3) Plexuses - they are formed by postganglionic fibers around the arteries.

* Response plan for organ innervation

1. Center of innervation.

2. Preganglionic fibers.

3. The node in which the switching of nerve fibers occurs.

4. Postgangionary fibers

5. Effect on the organ.

Sympathetic innervation of the salivary glands

1. The center of innervation is located in the spinal cord in the lateral horns in the nucleus intermediolateralis of the first two thoracic segments.

2. Preganglinar fibers are part of the anterior root, spinal nerve and ramus communicans albus

3. Switching to ganglion cervicale superius.

4. Postganglionic fibers form the plexus caroticus externus

5. Decreased secretion.

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Salivary glands! - these are secretory organs that perform important and diverse functions that affect the state of the body, its digestive and hormonal systems.

Functions of the salivary glands:

Secretory;

Incretory - isolation of polypeptide proteins having general structure with hormones:

a) insulin;

b) parotina;

c) erythropoietin;

d) thymotropic factor;

e) nerve growth factor, epithelial growth factor;

Recretory (transient passage of substances from the blood into saliva);

Excretory.

Functions of saliva:

Digestive;

Protective;

Buffer;

Mineralizing.

Three pairs of large and many small salivary glands have a lobular structure, each lobule has a terminal section and an excretory duct. Saliva is formed in the secretory terminal formations (acini) and undergoes secondary changes in the duct system.

The blood supply to the large salivary glands is carried out by the branches of the external carotid artery (Fig. 1), and the outflow of blood occurs into the system of the external and internal jugular veins. The microcirculatory bed of each lobule begins

It is found in arterioles, which break up into capillaries that entwine the end sections, forming a finely looped network. The peculiarity of the blood supply to the salivary glands is the presence of numerous anastomoses that promote uniform redistribution of blood in the parenchyma of the gland. According to some data, the salivary glands, even at rest, have a high volumetric blood flow - 30-50 ml/min per 100 g of tissue. With the secretion of the glands and the vasodilation that occurs, the blood flow increases to 400 ml/min per 100 g. The arteries that enter the gland, dividing repeatedly into arterioles, first form capillaries of the ductal part of the glands. The blood, having passed them against the flow of saliva in the ducts, again collects into vessels, which then form the second capillary network of the terminal (acinar) part of the gland, from where the blood flows into the veins (acinar) and ductal parts. In the absence of stimulation, 69% of saliva is secreted by the submandibular glands, 26% by the parotid glands and 5% by the sublingual glands.

Rice. 1. Microcirculatory bed of the salivary gland lobules (Denisov A.B. Salivary glands. Saliva)

The innervation of the salivary glands is distributed into the innervation of the glandular part and blood vessels (Fig. 2). Glandular tissue contains receptors for vegetative mediators

nervous system and to biogenic amines - serotonin, histamine.

Salivation is an integral component of chewing and swallowing acts. Inclusion of salivary glands in the device functional system chewing is carried out according to the reflex principle.

The main receptive field for the salivary reflex is the oral mucosa. Salivation can have not only an unconditioned reflex mechanism, but also a conditioned reflex mechanism: at the sight and smell of food, talking about food.

The salivary center is located in the reticular formation of the medulla oblongata and is represented by the superior and inferior salivary nuclei.

The efferent pathway of salivation is represented by fibers of the parasympathetic and sympathetic nerves. Parasympathetic innervation carried out from the upper and lower salivary nuclei.

From the superior salivary nucleus, excitation is directed to the sublingual, submandibular and small palatine salivary glands. Preganglionic fibers to these glands come as part of the chorda tympani; they conduct impulses to the submandibular and subhyoid vegetative nodes. Here the excitation switches to postganglionic secretory nerve fibers, which, as part of the lingual nerve, approach the submandibular and sublingual salivary glands. Preganglionic fibers of the minor salivary glands go as part of the greater petrosal nerve (a branch of the intermediate nerve) to the pterygopalatine ganglion. From it, postganglionic fibers as part of the greater and lesser palatine nerves approach the minor salivary glands of the hard palate.

From the inferior salivary nucleus, excitation is transmitted along preganglionic fibers running as part of the inferior petrosal nerve (a branch of the glossopharyngeal nerve) to the ear node, in which a switch occurs to postganglionic fibers, which, as part of the auriculotemporal nerve (a branch of the trigeminal nerve), innervate the parotid salivary gland.

Cores sympathetic division of the autonomic nervous system are located in the lateral horns of the 2-6 thoracic segments of the spinal cord. Excitation from them enters the superior cervical sympathetic ganglion via preganglionic fibers, and then reaches the salivary glands via postganglionic fibers along the external carotid artery.

Irritation of the parasympathetic fibers innervating the salivary glands causes abundant secretion of saliva, which contains many salts and relatively few organic substances. Irritation of sympathetic fibers leads to the release of a small amount of saliva, rich in organic substances and containing relatively few salts.

Rice. 2. Innervation of the salivary glands (Denisov A.B. Salivary glands. Saliva)

Denervation of the salivary glands leads to continuous (paralytic) secretion. In the first days, degenerative secretion is recorded due to the ability of degenerating nodes to synthesize acetylcholine in the absence of the ability to retain it. As far as

In early degeneration, the release of acetylcholine decreases, while the sensitivity of damaged cells to humoral factors, in particular pyrocatechins, which are formed during painful stimulation, hypoxia and other conditions, increases.

In the regulation of salivation, a significant role is played by humoral factors - hormones of the pituitary gland, adrenal glands, pancreas and thyroid glands, and metabolites. Humoral factors regulate the activity of the salivary glands in different ways, acting either on the peripheral apparatus (secretory cells, synapses) or directly on nerve centers brain.

The central apparatus of regulation of the salivary glands ensures the adaptability of salivation to those needs of the body that are this moment are significant for him. Yes, when irritated taste buds saliva is released, rich in organic substances and enzymes; when thermoreceptors are irritated, it is liquid and poor in organic substances.

Thus, in the diagnosis of diseases of the salivary glands, their consistent and thorough examination is of decisive importance.