Innervation of the salivary glands. Salivary glands

Digestion - includes a complex of mechanical and chemical processes aimed at food processing, absorption of nutrients, the secretion of special enzymes in the mouth, stomach and intestines, and the release of undigested food components.

Intracellular and parietal digestion. Depending on the localization of the digestion process, it is divided into intracellular and extracellular. Intracellular digestion - This is the hydrolysis of nutrients that enter the cell as a result of phagocytosis and pinocytosis. In the human body, intracellular digestion takes place in leukocytes and in cells of the lympho-reticulo-histiocytic system.

Extracellular digestion subdivided into distant (cavity) and contact (parietal, membrane).

Distant (abdominal) digestion is carried out at a considerable distance from the place of enzyme formation. Enzymes in the composition of digestive secretions carry out the hydrolysis of nutrients in the cavities of the gastrointestinal tract.

Contact (parietal, membrane) digestion is carried out by enzymes fixed on the cell membrane (A. M. Ugolev). The structures on which the enzymes are fixed are represented in the small intestine by the glycocalyx. Initially, the hydrolysis of nutrients begins in the lumen of the small intestine under the influence of pancreatic enzymes. Then the formed oligomers are hydrolyzed in the glycocalyx zone by the enzymes of the pancreas adsorbed here. Directly at the intestinal cell membranes, the hydrolysis of the formed dimers is produced by intestinal enzymes fixed on it. These enzymes are synthesized in enterocytes and transferred to the membranes of their microvilli.

Principles of regulation of digestion processes... The activity of the digestive system is regulated by nervous and humoral mechanisms. Nervous regulation of digestive functions is carried out by sympathetic and parasympathetic influences.

The secretion of the digestive glands is conditioned reflexively and unconditionally reflexively. Such influences are especially pronounced in the upper part of the digestive tract. As we move to the distal parts of the digestive tract, the participation of reflex mechanisms in the regulation of digestive functions decreases. This increases the importance of humoral mechanisms. In the small and large parts of the intestine, the role of local regulatory mechanisms is especially great - local mechanical and chemical irritation increases the activity of the intestine at the site of the stimulus. Thus, there is a gradient in the distribution of nervous, humoral and local regulatory mechanisms in the digestive tract.

Local mechanical and chemical stimuli affect the function of the digestive tract through peripheral reflexes and through the hormones of the digestive tract. Chemical stimulants of nerve endings in the gastrointestinal tract are acids, alkalis and products of hydrolysis of food substances. Entering the blood, these substances are carried by its current to the digestive glands and excite them directly or through intermediaries. The volume of blood entering the stomach, intestines, liver, pancreas and spleen is about 30% of the stroke volume of the heart.

A significant role in the humoral regulation of the digestive organs belongs to the gastrointestinal hormones formed in the endocrine cells of the gastric mucosa, duodenum, jejunum, and the pancreas. They affect the motility of the digestive tract, the secretion of water, electrolytes and enzymes, the absorption of water, electrolytes and nutrients, and the functional activity of the endocrine cells of the gastrointestinal tract. In addition, gastrointestinal hormones affect metabolism, endocrine and cardiovascular functions, and the central nervous system. Several gastrointestinal peptides are found in various structures in the brain.

By the nature of the influences, regulatory mechanisms can be divided into triggering and corrective ones. The latter ensure the adaptation of the volume and composition of the digestive juices to the quantity and quality of the food contents of the stomach and intestines (GF Korotko).

The secretory function of the salivary glands in animals is studied in acute and chronic experiments. The acute method consists in the introduction of a cannula under anesthesia into the duct of the gland, through which saliva is secreted. Chronic (according to Pavlov) - by a surgical method, one of the ducts of the gland is brought out to the cheek (fistula) and a funnel for collecting saliva is fixed to it (Fig. 13.5). experimental methods

FIG. 13.5.

make it possible to study the influence of various factors (food, nervous, humoral) on the secretory function of the salivary glands. In humans, a Lashley-Krasnogorsky capsule is used, which is fixed on the mucous membrane of the cheek opposite the duct of the gland.

Saliva secretion carried out by the salivary glands reflexively.

Parotid the glands, the largest among the salivary glands, form a serous secret, which includes proteins and a significant amount of water; its number is up to 60 % saliva.

Submandibular and sublingual glands produce a mixed serous-mucous secretion, which includes proteins and mucus - mucin, in an amount of 25-30% and 10-15 % respectively. Small glands of the tongue and oral cavity secrete mainly mucus - mucin.

The salivary glands produce 0.8-2.0 liters of saliva per day, which contains water, electrolytes (the same composition as in blood plasma), proteins, enzymes, mucin, protective factors (bactericidal, bacteriostatic), insulin-like protein, parotin ... pH of saliva 6.0-7.4. The dry residue is composed of inorganic and organic substances.

■ Enzymes saliva represent: alpha-amylase, which begins the hydrolysis of carbohydrates to disaccharides: DNases and RNAases - break down amino acids: "lingual" lipase - produced by the salivary glands of the tongue and begins lipid hydrolysis. A significant group of enzymes (more than 20) are involved in the hydrolysis of substances that form dental plaque, and thereby reduce dental deposits.

■ Mucin is a glycoprotein that protects the oral mucosa from mechanical damage and contributes to the formation of a food lump.

Saliva's protective factors include:

1 Lysozyme (muramidase), which destroys the membranes of bacteria, namely, breaks 1-4 bonds between N-acetyl-muramic acid and N- acetylglucosamine - two main mucopeptides that make up the membranes of bacteria. Lysozyme enters the oral cavity along with the saliva of large and small salivary glands, with tissue exudate of the gingival fluid and from the leukocytes that make up saliva. At a high concentration of lysozyme in the oral cavity, the bacterial flora becomes ineffective.

2 Secretory IgA, less - IgG and IgM. Secretory IgA are produced by the salivary glands, they are more resistant to digestive secretions than those in the blood plasma, while IgM is predominantly exudate of fluid secreted by the gums. IgA facilitates the aggregation of microbes, forming complexes with proteins of the surface of the epithelium, protects it and increases the phagocytic activity of leukocytes.

3 Peroxidases and thiocyanates saliva acts as antibacterial enzymes.

FIG. 13.6.

4 Saliva saturation calcium salts reduces decalcification of enamel.

The mechanism of saliva formation , first described by K. Ludwig, testifies that secretion is not a passive filtration of fluid from blood vessels - it is the result of the active function of secretory cells. Primary saliva is formed in the acinar cells of the glands. Acinus cells synthesize and secrete enzymes and mucus, spillage - form the liquid part of saliva, its ionic composition (Fig. 13.6).

Phases of the secretory cycle. Substances necessary for the synthesis of enzymes, primarily amino acids, penetrate into the secretory cell through the basement membrane of the capillary. The synthesis of prosecret (the precursor of the enzyme) takes place on ribosomes, from which it is brought into the Golgi apparatus for maturation. The mature secretion is packed into granules and stored in them until the time of release into the lumen of the gland, which is stimulated by Ca 2+ ions.

The liquid part of saliva is formed by the duct cells. At first, it resembles blood plasma, in which there is a high concentration of sodium and chlorine ions and much less - potassium and bicarbonate ions. The formation of liquid saliva comes with the expenditure of energy using oxygen, which is necessary for the synthesis of ATP. When saliva passes through the ducts, the ionic composition changes in it - the amount of sodium and chlorine decreases and the amount of potassium and bicarbonate ions increases. The reabsorption of sodium ions and the secretion of potassium ions are regulated by aldosterone (as in the kidney tubules). Ultimately, secondary saliva is produced and secreted into the mouth (see Figure 13.6). The level of blood flow in the gland, which depends on the metabolites formed in it, especially kinins (bradykinin), which cause local vasodilation and an increase in secretion, affects the saline dormancy.

In response to the action of various stimuli (with different properties), the salivary glands secrete an unequal amount of saliva, with a different composition. So, when eating dry food, a large amount of liquid saliva is released; when consuming liquid (milk), little is produced, but there is a lot of mucus in it.

Innervation of the salivary glands carried out by parasympathetic and sympathetic nerves. Parasympathetic innervation of the gland is obtained from the nuclei of the cranial nerves of the medulla oblongata: parotid - from the lower salivary nucleus - IX pair (lingo-pharyngeal), submandibular and sublingual - from the upper salivary nucleus - VII pair (facial). Stimulation of the parasympathetic nervous system causes the release of a large amount of liquid saliva, poor in organic matter.

Nice innervation to all salivary glands is given by the centers of the lateral horns of the II-IV thoracic segments of the spinal cord, through the upper cervical sympathetic ganglion they are sent to the glands. When the sympathetic nerves are activated, little saliva is released, but it has a high concentration of organic substances (enzymes, mucin).

Regulation salivation carried out by folding-reflex mechanisms with the help of:

1 conditioned reflexes the sight and smell of food, sounds accompanying the act of eating, their center is located in the cerebral cortex (conditioned reflex phase) 2 unconditioned reflexes, food-related receptors of the tongue, oral mucosa; their center is located in the salivary nuclei of the medulla oblongata (insane reflex phase). Afferent entrance to the central nervous system during the implementation of unconditioned reflexes - sensitive fibers of the V, VII, IX and X pairs of cranial nerves; efferent output - parasympathetic fibers VII, IX pairs and sympathetic neurons of the lateral horns II-IV segments of the thoracic region (Figure 13.7).

Penetrating into the eyeball, sympathetic fibers approach the pupil dilator. Their function is to dilate the pupil and constrict the blood vessels of the eye. The defeat of the efferent sympathetic pathway is accompanied by constriction of the pupil on the side of the same name and the expansion of the blood vessels of the eye.

Pathways to the eyeball are also two-neuronal. The bodies of the first neurons are located in the accessory nucleus of the oculomotor nerve. Their axons are preganglionic fibers that run as part of the oculomotor nerve to the ciliary node, where they end on effector neurons. Axons of the second neurons, which represent postganglionic fibers, originate from the bodies of the nerve cells of the ciliary node. The latter pass as part of the short ciliary nerves to the ciliary muscle and the muscle that constricts the pupil.

The defeat of the parasympathetic efferent pathway leads to the loss of the accommodating ability of the eye for far and close vision of objects and the dilation of the pupil.

Innervation of the lacrimal gland

Afferent fibers, conducting impulses from the conjunctiva of the eyeball and the lacrimal gland, pass into the central nervous system as part of the lacrimal nerve, which is a branch of the optic nerve (from the first branch of the trigeminal nerve). They end on the spinal nucleus of the trigeminal nerve. Further, there is a closure to the autonomic centers: the upper salivary nucleus and through the reticular formation to the lateral horns of the upper thoracic segments of the spinal cord (Fig. 11).

Efferent sympathetic pathways to the lacrimal gland are two-neuronal. The bodies of the first neurons are located in the lateral intermediate nucleus of the lateral horns of the spinal cord at the level of the upper thoracic segments. Departing from them preganglionic fibers reach the upper cervical node of the sympathetic trunk in the composition of the white connecting branches and its internodal branches. Postganglionic fibers cells of the superior cervical node pass sequentially through the internal carotid plexus, deep petrosal nerve, and the nerve of the pterygoid canal. Then they go along with parasympathetic fibers to the maxillary nerve, and along the anastomosis between the zygomatic and lacrimal nerves reach the lacrimal gland.

Irritation of sympathetic fibers causes a decrease or delay in lacrimation. The cornea and conjunctiva of the eye become dry.

Efferent parasympathetic pathways to the lacrimal gland are also two-neuronal. The bodies of the first neurons lie in the superior salivary nucleus. Preganglionic fibers are sent from the superior salivary nucleus as part of the intermediate nerve together with the facial nerve in the same canal, and then in the form of a large stony nerve to the pterygo-palatine node, where they end on the second neurons.

Postganglionic fibers the cells of the pterygo-palatine node pass as part of the maxillary and zygomatic nerves, and then, through the anastomosis with the lacrimal nerve, to the lacrimal gland.

Irritation of parasympathetic fibers or the upper salivary nucleus is accompanied by an increase in the secretory function of the lacrimal gland. Cutting the fibers can cause the tearing to stop.

INERVATION OF LARGE SALIVARY GLANDS

Parotid salivary gland.

Afferent fibers begin with sensitive endings in the mucous membrane of the posterior third of the tongue (lingual branch of the IX pair of cranial nerves). Glossopharyngeal nerve conducts gustatory and general sensitivity to a single nucleus located in the medulla oblongata. Intercalary neurons switch the path to the parasympathetic cells of the lower salivary nucleus, and along the reticulospinal path to the cells of the sympathetic centers located in the lateral horns of the upper thoracic segments of the spinal cord (Fig. 12).

Efferent sympathetic preganglionic fibers, sending impulses to the parotid salivary gland, from the lateral intermediate nucleus of the lateral horns of the spinal cord (T 1 -T 2) go as part of the anterior roots of the spinal nerves, white connecting branches to the sympathetic trunk and through the interganglionic connections reach the upper cervical node. Here, a switch to another neuron occurs. Postganglionic fibers in the form of external carotid nerves, they form a periarterial plexus around the external carotid artery, in which they approach the parotid gland.

Irritation of sympathetic fibers is accompanied by a decrease in the liquid part of the secreted saliva, an increase in its viscosity and, accordingly, dry mouth.

Efferent parasympathetic preganglionic fiber start from the lower salivary nucleus of the glossopharyngeal nerve, pass into the tympanic nerve, through the tympanic tubule go into the tympanic cavity, continue in the form of a small stony nerve. Through the sphenoid-stony cleft, the small petrosal nerve leaves the cranial cavity and approaches the ear node located next to the mandibular nerve of the V pair of cranial nerves, where they switch to the second neurons. Fibers of second neurons ( postganglionic) as part of the ear-temporal nerve reach the parotid gland.

Parasympathetic fibers conduct impulses that enhance the secretory activity of the parotid salivary glands. Irritation of the nucleus or nerve conductors is accompanied by profuse salivation.

Submandibular and sublingual salivary glands .

Afferent (ascending) fiber begin with sensitive endings in the mucous membrane of the anterior 2/3 of the tongue, and the general sensitivity goes along the lingual nerve of the V pair of cranial nerves, and gustatory sensitivity goes along the fibers of the drum string. The axons of afferent neurons are switched on the cells of a single nucleus, the processes of which are connected to the parasympathetic superior salivary nucleus and the nuclei of the reticular formation. Through the reticulospinal pathway, the reflex arc closes to the centers of the sympathetic nervous system (Th 1-Th 2).

The neurons from which the preganglionic fibers depart are located in the lateral horns of the spinal cord at the Th II -T VI level. These fibers approach the upper cervical ganglion (gangl.cervicale superior), where they end on postganglionic neurons that give rise to axons. These postganglionic nerve fibers, together with the choroid plexus accompanying the internal carotid artery (plexus caroticus internus), reach the parotid salivary gland and, as part of the choroid plexus surrounding the external carotid artery (plexus caroticus externus), the submandibular and sublingual salivary glands.

Parasympathetic fibers play a major role in the regulation of salivary secretion. Irritation of parasympathetic nerve fibers leads to the formation of acetylcholine in their nerve endings, which stimulates the secretion of glandular cells.

The sympathetic fibers of the salivary glands are adrenergic. Sympathetic secretion has a number of features: the amount of saliva released is significantly less than when chorda tympani is irritated, saliva is released in rare drops, it is thick. In humans, stimulation of the sympathetic trunk in the neck causes secretion of the submandibular gland, while secretion does not occur in the parotid gland.

Salivary centers medulla oblongata consist of two symmetrically located neural pools in the reticular formation. The rostral part of this neuronal formation - the upper salivary nucleus - is connected with the submandibular and sublingual glands, the caudal part - the lower salivary nucleus - with the parotid gland. Stimulation in the area between these nuclei induces secretion from the submandibular and parotid glands.

The diencephalic region plays an important role in the regulation of salivation. When the anterior part of the hypothalamus or the preoptic region (center of thermoregulation) is stimulated, the mechanism of heat loss is activated in animals: the animal opens its mouth wide, dyspnea and salivation begin. When the posterior hypothalamus is stimulated, strong emotional arousal and an increase in salivation occur. Hess (Hess, 1948), upon stimulation of one of the zones of the hypothalamus, observed a pattern of eating behavior, which consisted of movements of the lips, tongue, chewing, salivation and swallowing. The amygdala (amigdala) has close anatomical and functional connections with the hypothalamus. In particular, stimulation of the amygdala complex induces the following food reactions: licking, sniffing, chewing, salivation, and swallowing.

The secretion of saliva, obtained by irritation of the lateral hypothalamus, after removal of the frontal lobes of the cerebral cortex increases significantly, which indicates the presence of inhibitory influences of the cerebral cortex on the hypothalamic parts of the salivary center. Salivation can also be caused by electrical stimulation of the olfactory brain (rhinencephalon).

In addition to the nervous regulation of the work of the salivary glands, a certain influence on their activity of sex hormones, hormones of the pituitary gland, pancreas and thyroid glands has been established.

Some chemicals can excite or, conversely, inhibit the secretion of saliva, acting either on the peripheral apparatus (synapses, secretory cells) or on the nerve centers. Abundant saliva is observed during asphyxia. In this case, increased salivation is a consequence of irritation of the salivary centers with carbonic acid.

The effect of some pharmacological substances on the salivary glands is associated with the mechanism of transmission of nerve influences from parasympathetic and sympathetic nerve endings to the secretory cells of the salivary glands. Some of these pharmacological substances (pilocarpine, proserin and others) stimulate salivation, others (for example, atropine) inhibit or stop it.

Mechanical processes in the oral cavity.

The upper and lower ends of the digestive tract differ from other parts in that they are relatively fixed to the bones and consist not of smooth, but mainly striated muscles. Food enters the oral cavity in the form of lumps or liquids of various consistencies. Depending on this, it either immediately passes to the next section of the digestive tract, or undergoes mechanical and initial chemical processing.

Chewing. The process of mechanical processing of food - chewing - consists in crushing its solid components and mixing with saliva. Chewing also contributes to the assessment of the taste of food and is involved in arousal of salivary and gastric secretions. Since food is mixed with saliva when chewing, it facilitates not only swallowing, but also partial digestion of carbohydrates by amylase.

The act of chewing is partly reflex, partly voluntary. When food enters the oral cavity, irritation of the receptors of its mucous membrane (tactile, temperature, taste) occurs, from where impulses are transmitted along the afferent fibers of the trigeminal nerve to the sensory nuclei of the medulla oblongata, the nucleus of the optic tubercle, and from there to the cerebral cortex. From the brainstem and the optic tubercle, collaterals extend to the reticular formation. The motor nuclei of the medulla oblongata, the red nucleus, the black matter, the subcortical nuclei and the cerebral cortex take part in the regulation of chewing. These structures are chewing center... Impulses from it along the motor fibers (mandibular branch of the trigeminal nerve) go to the masticatory muscles. In humans and most animals, the upper jaw is motionless, so chewing is reduced to movements of the lower jaw, carried out in the following directions: from top to bottom, front to back and sideways. The muscles of the tongue and cheeks play an important role in keeping food between the chewing surfaces. The regulation of the movements of the lower jaw for the implementation of the act of chewing occurs with the participation of proprioceptors located in the thickness of the masticatory muscles. Thus, the rhythmic act of chewing occurs involuntarily: The ability to chew consciously and to regulate this function at an involuntary level is presumably associated with the representation of the act of chewing in the structures of various levels of the brain.

When registering chewing (masticiography), the following phases are distinguished: rest, the introduction of food into the mouth, approximate, basic, the formation of a food lump. Each of the phases and the entire period of chewing have a different duration and character, which depends on the properties and amount of chewed food, age, appetite with which food is taken, individual characteristics, the usefulness of the chewing apparatus and its control mechanisms.

Swallowing. According to the theory of Magendie (1817), the act of swallowing is divided into three phases - oral arbitrary, pharyngeal involuntary, fast and esophageal, also involuntary, but slow. From the food mass crushed and moistened with saliva, which is in the mouth, a food lump is separated, which, with the movements of the tongue, moves to the midline between the front of the tongue and the hard palate. At the same time, the jaws are compressed and the soft palate rises. Together with the contracted palatopharyngeal muscles, it forms a septum that blocks the passage between the mouth and the nasal cavity. To move the food bolus, the tongue moves backward, pressing against the palate. This movement moves the lump into the pharynx. At the same time, intraoral pressure increases and promotes pushing the food bolus towards the least resistance, i.e. back. The entrance to the larynx is closed by the epiglottis. At the same time, the glottis is also closed by squeezing the vocal cords. As soon as a lump of food enters the pharynx, the anterior arches of the soft palate contract and, together with the root of the tongue, prevent the lump from returning to the oral cavity. Thus, the food lump with contraction of the pharyngeal muscles can only push into the opening of the esophagus, which is widened and pushed towards the pharyngeal cavity.

The change in pressure in the pharynx during swallowing also plays an important role. Usually, the esophageal sphincter is closed before swallowing. During swallowing, the pressure in the pharynx rises sharply (up to 45 mm Hg). When the high pressure wave reaches the sphincter, the muscles of the latter relax and the pressure in the sphincter rapidly decreases to the level of external pressure. Thanks to this, the lump passes through the sphincter, after which the sphincter closes, and the pressure in it rises sharply, reaching 100 mm Hg. Art. At this time, the pressure in the upper part of the esophagus reaches only 30 mm Hg. Art. A significant difference in pressure prevents the food bolus from being thrown from the esophagus into the pharynx. The entire swallowing cycle is approximately 1 second.

This whole complex and coordinated process is a reflex act, which is carried out by the activity of the center of swallowing of the medulla oblongata. Since it is located close to the respiratory center, breathing stops every time a swallowing act occurs. The movement of food through the pharynx and along the esophagus into the stomach occurs as a result of successive reflexes. During the implementation of each of the links in the chain of the swallowing process, the receptors embedded in it are irritated, which leads to the reflex inclusion of the next link in the act. Strict coordination of the components of the act of swallowing is possible due to the presence of complex interconnections between various parts of the nervous system, from the medulla oblongata to the cerebral cortex.

The swallowing reflex occurs when the receptor sensitive endings of the trigeminal nerve, upper and lower laryngeal and glossopharyngeal nerves, embedded in the mucous membrane of the soft palate, are irritated. Through their centripetal fibers, excitation is transmitted to the swallowing center, from where impulses propagate along the centrifugal fibers of the upper and lower pharyngeal, recurrent and vagus nerves to the muscles involved in swallowing. The swallowing center functions on an all-or-nothing basis. The swallowing reflex is carried out when afferent impulses reach the center of swallowing in a uniform row.

A slightly different mechanism for swallowing liquids. When drinking by pulling the tongue without breaking the lingual-palatine bridge, negative pressure is formed in the oral cavity and the liquid fills the oral cavity. Then the contraction of the muscles of the tongue, the floor of the oral cavity and the soft palate creates such a high pressure that under its influence the liquid is injected into the esophagus, which is relaxing at this moment, reaching the cardia almost without the participation of contraction of the constrictors of the pharynx and the muscles of the esophagus. This process takes 2-3 seconds.

Afferent way for the lacrimal gland is the lacrimal lake (n. lacrimalis; branch n. ophthalmicus from n. trigeminus), for the submandibular and sublingual - the lingual nerve (n. lingualis; branch of the mandibular nerve (n. mandibularis) from the trigeminal nerve (n. trigeminus)) and the tympanic string (chorda tympani; branch of the intermediate nerve (n. intermedius)), for the parotid - the ear-temporal nerve (n. auriculotemporalis) and glossopharyngeal nerve (n. glossopharyngeus).

Fig. one. Vegetative innervation of internal organs: a - parasympathetic part, b - sympathetic part; 1 - upper cervical node; 2 - lateral intermediate nucleus; 3 - superior cervical cardiac nerve; 4 - thoracic cardiac and pulmonary nerves, 5 - large celiac nerve; 6 - celiac plexus; 7 - lower mesenteric plexus; 8 - upper and lower hypogastric plexus; 9 - small celiac nerve; 10 - lumbar celiac nerves; 11 - sacral celiac nerves; 12 - parasympathetic nuclei of the sacral segments; 13 - pelvic celiac nerves; 14 - pelvic nodes; 15 - parasympathetic nodes; 16 - vagus nerve; 17 - ear node, 18 - submandibular node; 19 - pterygopalatine node; 20 - ciliary node, 21 - parasympathetic nucleus of the vagus nerve; 22 - parasympathetic nucleus of the glossopharyngeal nerve, 23 - parasympathetic nucleus of the facial nerve; 24 - parasympathetic nucleus of the oculomotor nerve (according to M.R.Sapin).

Efferent parasympathetic innervation of the lacrimal gland (fig. 1). The center lies in the upper part of the medulla oblongata and is connected with the upper nucleus of the intermediate nerve (nucleus salivatorius superior). Preganglionic fibers are part of the intermediate nerve (n. Intermedius), then the large stony nerve (n. Petrosus major) to the pterygopalatine node (g. Pterygopalatinum).

From here, the postganglionic fibers begin, which, as part of the maxillary nerve (n. Maxillaris) and further its branches, the zygomatic nerve (n. Zygomaticus), through connections with the lacrimal lake (n. Lacrimalis) reach the lacrimal gland.

Efferent parasympathetic innervation of the submandibular and sublingual glands... Preganglionic fibers go from the upper nuclei of the intermediate nerve (nucleus salivatorius superior) as part of the intermediate nerve (n. Intermedius), then the tympanic string (chorda tympani) and the lingual nerve (n. Lingualis) to the submandibular node (g. Submandibulare), from where the postganglionic fibers reaching the glands.

Efferent parasympathetic innervation of the parotid gland... Preganglionic fibers go from the lower nuclei of the intermediate nerve (nucleus salivatorius inferior) as part of the glossopharyngeal nerve (n. Glossopharyngeus), then the tympanic nerve (n. Tympanicus), the small stony nerve (n. Petrosus minor) to the ear node (g. Oticum). From here, the postganglionic fibers begin, going to the gland as part of the auriculotemporal nerve (n. Auriculotemporalis) of the fifth nerve.

Function: enhancing the secretion of the lacrimal and salivary glands; vasodilation of the glands.

Efferent sympathetic innervation all named glands. Preganglionic fibers begin in the lateral horns of the upper thoracic segments of the spinal cord and end in the upper cervical node of the sympathetic trunk. Postganglionic fibers begin in this node and reach the lacrimal gland as part of the internal carotid plexus (pl.caroticus internus), to the parotid - as part of the external carotid plexus (pl.caroticus externus) and to the submandibular and sublingual glands - through the external carotid plexus (pl . caroticus externus) and then through the facial plexus (pl. facialis).

Function: delaying the separation of saliva (dry mouth).