Paired salivary glands in humans. Everything about the salivary glands: anatomy, function and disease. Inflammation of the sublingual salivary gland

The salivary glands are in oral cavity and saliva. They are divided into large and small. According to the quality of the secreted secretion, there are mixed, mucous and proteinaceous.

They are located in the mucous membrane of the tongue, cheeks, lips, palate, as well as in the sublingual, submandibular, anterior and posterior lingual and parotid glands (the largest of all).

Small salivary glands are located in the region of the tongue, palate, cheeks and lips. Large salivary glands, also called paired, are located in the sublingual, submandibular and parotid layers.

The parotid salivary gland is located in the postmandibular fossa and consists of several lobules, the submandibular gland is located in the submandibular triangle, the sublingual gland is located on the maxillary-hyoid muscle.

About functional necessity

The action of the salivary glands:

• wetting the oral cavity;
• liquefaction of food;
• chewing food;
• articulation;
• increased taste;
• protection of teeth from various damages (thermal, mechanical);
• cleansing the oral cavity.

Complete detailed anatomy of the salivary glands

Saliva is secreted in the large salivary glands. Numerous enzymes that make up the glands are actively involved in the digestion process. Enzymes are protein substances, their functions are diverse and very important, from the initial chemical processing in the mouth of food to the moment the stomach produces juice.

From the research of specialists it follows that the action of enzymes of the salivary glands continues after ingestion of food for up to half an hour.

Saliva composition:

• enzymes (amylase, hydrolase, protease, maltase, phosphatase);
• inorganic substances: sulfates, chloride anions, phosphates;
• cations of magnesium, potassium, sodium, calcium;
• trace elements (nickel, iron);
• proteins (for example, mucin, which sticks together food particles and helps in the formation of a food lump); lysozyme (has a bactericidal effect).

Although food is in the mouth for a few seconds, the process of digestion begins already there, thanks to the presence of the salivary glands.

Complete breakdown of food occurs in the gastrointestinal tract.

Saliva functions:

• digestive;
• excretory;
• protective;
• trophic.

In the photo salivon is a structural and functional unit of the salivary gland

Saliva is formed from a special secretion that is secreted by the parotid gland, small and large salivary glands. Mixing in the mouth with other elements, saliva begins to perform its immediate functions.

Human saliva contains hundreds of thousands of microbes that enter the mouth along with water, dust, and smoke. People have become immune to many microbes, the body neutralizes them, and the beneficial microorganisms of saliva also take an active part in this process.

However, viruses mutate, and through unwashed hands or poorly washed food, many viruses can enter the mouth to which a person is not immune. Therefore, hygiene of hands, mouth, vegetables and fruits is very important.

After all, any infection can cause a huge amount of enamel and, mucous throat, and the whole organism as a whole.

In the world of interesting

Typically, the salivary glands produce approximately 2,200 mg of saliva per day. However, the quantity changes due to:

All negative emotional worries severe pain, overstrain of mental activity of the brain inhibits salivation, so-called lack of appetite also occurs.

However, even during conversations about food, at the sounds of cooked dishes, at the sight of food, a conditioned-irritable reflex is triggered in a person and salivation increases.

Possible disorders and diseases

Pathologies of the glands develop very rarely, for example, due to injury, traumatic bruises of the face or head, with a congenital defect of the salivary glands (for example, the absence of such):

Possible causes and symptoms

Inflammation causes:

• narrowing of the parotid duct;
• viral and infectious lesions (flu, acute respiratory infections, acute respiratory viral infections, measles, otitis media, tonsillitis,);
• the appearance in the duct of a plug from a compacted mixture of viruses or leukocytes;
• as a complication in professional activities for those who are engaged in glassblowing, playing wind instruments.

Inflammatory processes of the salivary glands are manifested by the presence of sometimes very high temperature body, sometimes with an increase in subfebrile temperature.

Symptoms of the inflammatory process:

• increased body temperature;
• swelling, swelling, and enlargement of the salivary gland, or the location of that gland;
• soreness on palpation, pain on swallowing;
• the presence of pus going into the oral cavity;
• bad breath,;
• redness at the site of inflammation.

A few words about the main thing

The treatment of diseases of the salivary glands includes the use of those agents that increase salivation, the appointment of antibiotics, physiotherapy, rinsing. With purulent contents and the presence of stones, surgical intervention is performed.

As a preventive measure, it is necessary to carefully monitor the oral hygiene, the condition of the teeth, tonsils.

At the slightest infection, immediately rinse the throat, treat teeth in a timely manner, immediately consult a doctor for diagnosis and prescription of professional treatment.

A person has small and large salivary glands. The group of small glands includes buccal, labial, molar, palatine and lingual. They are found in the thickness of the oral mucosa. Small glands are divided into 3 types according to the nature of saliva secreted - mucous, serous or mixed. The large salivary glands are called the paired parotid, sublingual and submandibular.

Parotid topography

The parotid glands, the largest of all, secrete a protein secretion. The glands are located in the postmaxillary fossa, adjacent in depth to the muscles extending from the styloid process, the pterygoid and digastric muscles. The upper edge of the gland is located at the external auditory canal and the membranous part of the temporal bone, the lower edge is near the corner of the lower jaw. The superficial part of the glands lies under the skin, covers the chewing muscle and the branch of the lower jaw. Outside, the parotid glands have a dense fibrous capsule fused with the superficial layer of the neck's own fascia.

The organ tissue is represented by glandular lobules with an alveolar structure. The walls of the vesicles-alveoli are composed of secretory cells. In the layers of fibrous tissue, the intercalated ducts run between the lobules. One pole of the secretory cells are directed towards the ducts. The bases of the cells are adjacent to the basement membrane, in contact with the myoepithelial elements capable of contraction. The flow of saliva from the ducts is stimulated by the contraction of myoepithelial cells.

Intralobular striated ducts from the inside are lined with a layer of prismatic epithelium. Connecting, the striated ducts form interlobular ducts with stratified squamous epithelium. The common excretory duct of the gland is formed by the fusion of the interlobular ducts. Its length is 2–4 cm. The duct lies on the surface of the cheek muscle 1–2 cm below the arch of the zygomatic bone. At the front edge of the muscle, it pierces the fatty body and the muscle itself, opening on the eve of the mouth opposite 1–2 upper molars ( large molar). The neurovascular bundle runs through the parotid gland. It contains the external carotid, superficial temporal, transverse and posterior ear arteries; facial nerve and posterior maxillary vein.

Submandibular topography

The submandibular gland secretes saliva of a mixed protein-mucous nature. It has a lobular structure. The gland is located in the submandibular fossa, bounded from above by the maxillary-hyoid muscle, behind - by the posterior abdomen of the digastric muscle, in front - by the anterior abdomen of this muscle, outside - by the subcutaneous muscle of the neck. The gland is covered with a capsule representing the layer of the neck's own fascia. The internal structure of the gland and its ducts is similar to the structure of the parotid gland. The excretory duct of the submandibular gland comes out on its medial surface and lies between the maxillary-hyoid and hyoid-lingual muscles.

Topography of the hyoid gland

The sublingual salivary gland predominantly secretes a mucous secret (mucin), formed by lobules with an alveolar structure. The gland is located under the side of the tongue on the sublingual muscle. The ducts of the sublingual and submandibular glands open on both sides of the frenum of the tongue.

Embryonic development

The salivary glands are formed from the epithelium of the oral cavity of the embryo, growing into the underlying mesenchyme. By the 6th week of the embryo's life, the submandibular and parotid glands are laid, at the 7th week - the sublingual glands. The secretory sections of the glands are formed from the epithelium, and the connective tissue septa between the lobules from the mesenchyme.

Functions

The saliva secreted by the glands has a slightly alkaline reaction. The secretion of the glands includes: inorganic salts, water, mucus, lysozyme, digestive enzymes - maltase and ptyalin. Saliva is involved in the breakdown of carbohydrates, moisturizes the mucous membrane, softens food and has a bactericidal effect on microorganisms.

Inflammatory diseases

The common name for inflammation of the salivary glands is sialoadenitis. Inflammatory diseases in the salivary glands occur when an infection enters with blood, lymph, or ascending from the oral cavity. The process of inflammation can be serous or purulent.

The viral infectious disease of the parotid gland is mumps or mumps. If the child has symmetrically swollen and sore parotid glands, these are symptoms of mumps. Male infertility is a complication of childhood mumps. The mumps virus damages not only the salivary glands, but also the germ cell tissue of the testicles. Prevention of mumps disease and its complications is the vaccination of preschool children against mumps.

Autoimmune inflammation with the accumulation of lymphoid cells in the tissues of the salivary glands develops in Sjogren's syndrome ( group of diffuse connective tissue diseases). Sjogren's syndrome is an autoimmune lesion of exocrine glands, joints and other connective tissue structures. The causes of the disease are considered viral infections coupled with a genetic predisposition.
Sialoadenitis stone - the formation of a stone in the salivary duct and reactive inflammation of the organ. The duct stone impedes the outflow of saliva and can cause the formation of a retention cyst.

Other reasons for the formation of retention cysts of the salivary glands: trauma, inflammation of the ducts, followed by their blockage and impaired salivary outflow. A cyst with a mucous (mucoid) secretion is called a mucocele.

Damage

Facial trauma can be accompanied by damage to the tissue and excretory ducts of the parotid gland. These injuries are dangerous by the formation of salivary fistulas, narrowing or clogging of the excretory duct, which leads to stagnation of saliva. Acute organ damage is determined by the following symptoms: salivation from a wound, the formation of salivary flow - the accumulation of saliva under the skin. Treatment of the consequences of trauma to the parotid gland - wound closure, surgery to restore the orifice of the duct when it is overgrown, surgical plastics of salivary fistulas

Tumor diseases

True tumors of the salivary glands can develop from the epithelium of the ducts and secretory cells. A benign neoplasm is called an adenoma, and a malignant neoplasm is called cancer or sarcoma. Tumors of the salivary glands do not hurt in the initial stages. Therefore, unilateral painless enlargement of the salivary gland is an indication for consultation with an oncologist and additional research.

Classification of neoplasms of the salivary glands by the nature of tumor growth:
benign forms;
local destructive forms;
malignant forms.

Of the benign tumors, the most common pleomorphic adenoma is a mixed tissue. It is characterized by slow growth over many years. The tumor can grow to a large size, but it is painless and does not metastasize. Malignancy of pleomorphic adenoma develops in 3.6-30%.

Indications for operations on the salivary glands:
the formation of stones in the salivary ducts;
benign and malignant tumors.

Treatment of cysts and tumors of the salivary glands - removal of the affected organ. The remaining healthy glands provide saliva production.

Diagnostic methods

For effective treatment salivary gland cancer assess the condition of the lymph nodes and surrounding tissues for the presence of metastases. More research is needed to determine the location, number and size of stones or tumors:
contrast radiography - sialography;
probing of ducts;
cytological examination of the secret;
Ultrasound - ultrasound examination;
magnetic resonance imaging or computed tomography;
biopsy, specifying the histological type of tumor.

About transplant

Scientists have developed an autotransplantation technique - transplanting one of the patient's own salivary glands under the skin of the temple. The operation can effectively treat dry eye syndrome, significantly improving the condition of patients. Clinical trials were carried out at the University of São Paulo in Brazil, where 19 people were operated. The results of the operations showed a good clinical effect. Surgeons from the University of Napoli and others medical centers Germany also got good results.

Experimental transplantation of embryonic tissue of the large salivary glands in laboratory animals ( guinea pigs) performed at the Belarusian State Medical University in 2003. The work of medical scientists in this direction continues.

Digestion begins long before food enters the esophagus. The process starts in the oral cavity: food is affected by saliva produced by the glands. Other functions of the salivary glands are equally important.

What is saliva?

The defining function of the salivary glands is the secretion of saliva, a viscous liquid with a complex composition: water, acid salts, trace elements, enzymes, vitamins, proteins.

The enzymes contained in the liquid break down food, and the digestion of fats begins. The particles are enveloped, glued together to facilitate movement along the esophagus.

The composition varies depending on the time of day, food and drink consumed, diseases, age, ecological situation. The indicator of oral health is the PH level. Normal values: 6.5 - 7.5.

The structure of the human salivary glands

The structure of organs is determined by their appearance. They are large and small; by the type of secret, mucous membranes, proteinaceous, mixed are distinguished. Dislocation of small - the mucous membrane of the lips, tongue, cheeks, palate. Large salivary glands - paired - are of three types:

1. Parotids are large, weighing 20-30 grams, located under the auricle, on the side of the lower jaw. Covered with a sheath of connective tissue, divided into lobules. The main function is the production of liquid saliva (one third of the total volume) with a high concentration of sodium and potassium chlorides.
2. Submandibular (15 grams) with the upper edge adjacent to the lower jaw. From them departs the excretory duct, which opens near the frenum of the tongue. Secrets the secret of low acidity.
3. The sublinguals weigh 5 grams and are located at the bottom of the mouth under the mucous membrane. Produced protein secretion, rich in mucin, with a high alkaline reaction.

The command to produce saliva is given by the brain.

The command to produce saliva is given by the brain. The centers located in the back section begin to work in certain situations - when thinking about food, chewing, mouth-watering smells, during stress. A large amount of secretion is produced when chewing: the muscles press on the glands, forcing them to work harder.

An interesting fact is noted in new studies: the parotid salivary glands are enlarged in those who like to talk on the phone; the amount of saliva produced is also above average.

Functions

The large and small salivary glands perform the same functions.

• endocrine - the production of biologically active substances like hormones;
• exocrine - secretion of mucus and proteins;
• excretory - excretion of metabolic products;
• filtration - filtration of nutrients from the blood.

The functions of the salivary glands make them an essential part of the digestive system.

The functions of the salivary glands make them an essential part of the digestive system. The oral cavity is moistened, food becomes available for chewing. Constant hydration is a condition for normal articulation, enhancing the taste of products. Thanks to chemical composition saliva protects tooth enamel from damage, preventing tooth decay.

With a reduced production of secretions, xerostomia is diagnosed - a syndrome of dry mouth. Soft tissues become irritated and vulnerable to infections. Dryness causes an unpleasant odor, change in taste, difficulty swallowing.

Sources:

1. Kurepina M.M., Ozhigova A.P., Nikitina A.A. Human anatomy. Moscow, 2010.
2. Fedyukovich N. Human anatomy and physiology. Tutorial. Rostov-on-Don, 2003.

- glands secreting a specific secret into the oral cavity - saliva.

In humans, in addition to numerous small salivary glands in the mucous membrane of the tongue, palate, cheeks and lips, there are 3 pairs of large salivary glands.

Types of salivary glands

There are the following paired large salivary glands:

• parotid;
• submandibular;
• sublingual.

Small salivary glands are divided into:

• buccal;
• molar;
• labial;
• lingual;
• glands of the hard and soft palate.

By the nature of the secreted secretion, the salivary glands are divided into:

• mucous membranes;
• serous (proteinaceous);
• mixed.

Serous glands are found mainly among the lingual, their saliva is rich in protein. The mucous glands are the palatine and part of the lingual, the saliva they produce is rich in mucus. Mixed - buccal, molar, labial and part of the lingual secrete saliva mixed in composition.

Large the parotid salivary glands belong to the protein glands, and the large submandibular and sublingual glands belong to the mixed (mucosal) glands. The secretory function of the large salivary glands is of great importance for digestion.

The main mass of the parotid large salivary gland is located in the posterior jaw fossa, the anterior part of the gland lies on the masseter muscle. From the lateral surface, the parotid salivary gland is covered with a dense fascia, from which there are bridges that divide the gland into lobules.

In the thickness of the parotid salivary gland pass the facial nerve with its main branches, the external carotid artery, and large veins. The mouth of the excretory duct of the gland is located on the mucous membrane of the cheek at the level of the first - second molars of the upper jaw.

Small.Small salivary glands are located in the thickness of the oral mucosa or in the submucous layer of the lips, cheeks, palate, tongue (the most numerous among the small salivary glands are the labial and palatine). The sizes of small glands are varied, their diameter ranges from 1 to 5 mm.

BLOOD SUPPLY

The blood supply to the parotid salivary glands is carried out by the branches of the external carotid arteries; blood flows into the system of the external and internal jugular veins.

The submandibular salivary gland is located in the submandibular triangle. Its excretory duct opens in the anterior sublingual region on the sublingual papilla. The blood supply is carried out by the branches of the facial artery.

The sublingual salivary gland is located in the sublingual space on the maxillary-hyoid muscle next to the excretory duct of the submandibular salivary gland. The main excretory duct opens on the sublingual papilla, the small excretory ducts - on the sublingual fold. The blood supply is carried out by the branches of the lingual artery.

EMBRYONIC SOURCES OF DEVELOPMENT AND THEIR DERIVATIVES

From the cutaneous ectoderm, the embryonic stratified epithelium of the oral cavity is formed, which gives rise to the parenchyma of the gland. The mesenchyme forms the stroma. From the neuroectoderm, ganglion plates appear, forming the nervous apparatus of the glands.

GENERAL FUNCTIONS

• exocrine - secretion of protein and mucous components of saliva;
• endocrine - secretion of hormone-like substances;
• filtration - filtration of liquid components of blood plasma from capillaries into saliva;
• excretory - the allocation of end products of metabolism.

SALIVATION

Salivation - the processes of secretion and excretion of saliva into the oral cavity. It is produced by the salivary glands. The secretion of the large salivary glands is intermittent; the saliva secreted by them serves to wet the food in the oral cavity. The secretion of small salivary glands in humans is continuous; the saliva they produce moisturizes the oral mucosa.

Reflex salivation is carried out under the influence of parasympathetic and sympathetic nerves with the participation of the salivary center, embedded in the medulla oblongata. Salivation is also influenced by humoral factors. For example, atropine suppresses the secretion of the salivary glands, and pilocarpine causes increased secretion even in conditions of their denervation.

Salivation can be impaired in various pathological conditions: excessive salivation (hypersalivation) is observed with nausea of \u200b\u200bvarious origins, neuralgia trigeminal nerve, stomatitis; decreased (hyposalivation) - with some infectious diseases, pneumonia, diabetes mellitus, etc.

DISEASES OF THE SALIVARY GLANDS

Pathologies of the development of the salivary gland are very rare. Sometimes the congenital absence of these glands is possible.

Salivary gland injuries are rarely isolated. They can occur as a result of gunshot wounds, cutting or bruised lacerations. The parotid gland is most commonly affected.

In this case, the integrity of the excretory duct of the gland, the facial nerve and the external carotid artery is often violated. A wound to the parotid gland can be complicated by the formation of a salivary fistula. Irritation and maceration of the skin is sometimes noted around the mouth of the fistula. Treatment is prompt. Recurrences of salivary fistula are frequent.

After an inflammatory process or trauma as a result of the closure of the common duct or the duct extending from the gland lobule, retention cysts are formed, more often in the small salivary glands (lower lip, cheeks), less often in the large salivary glands.

The most common salivary diseases:

• sialadenitis;
• sialolithiasis;
• mumps.

The function of the salivary glands is the production of saliva, which contains substances that take part in the breakdown of food. The glands are divided according to the type and type of secretion secreted.

Salivary glands

There are two types of salivary glands: large and small. The latter are located in the oral cavity and differ in the nature of the secreted fluid. The large salivary glands are divided into:

1. Parotid - these are the largest of all, they consist of a front and a back. They produce saliva, which takes part in the process of digesting food. The secret enters the oral cavity, passing through the parotid ducts.

The parotid glands are located next to the facial nerve, therefore, if their functionality is impaired, facial expressions may also suffer. They produce about 20% of the total volume of saliva secreted.

1. Submandibular produce a secret that consists of serous fluid and mucus. This is 70% of the total volume of saliva that enters the mouth through the submandibular canal.
2. Sublingual are under the tongue, producing mainly mucus. From here, about five percent of all saliva enters the oral cavity.

In the submucosal space of the oral cavity there are about a thousand small ducts, they are localized in the labial, buccal tissue, tongue, palate, between muscle tissues. Small salivary glands end in separate ducts or one common one, through which saliva is secreted and covers all mucous membranes.

Functions, task and composition of saliva

Main goals:

• moisturizing the oral mucosa,
• wetting food while chewing,
• increased taste sensations,
• protection of teeth,
• a natural process of cleansing mucous membranes: saliva washes away plaque, bacteria, viruses from them.

The location of the salivary glands.

The large salivary glands produce saliva. It contains a large number of enzymes that are involved in digestion. Enzymes are protein components responsible for the process of digesting food from the moment it is processed in the mouth to the process of digestion in the stomach.

The salivary glands perform an important excretory function: in case of impaired renal function and a decrease in the efficiency of their activity, excretions (urea, carbon dioxide, ammonia, creatine) begin to be produced in saliva in a large volume. Saliva is directly involved in the elimination of hormones (androgens, estrogens) from the body.

The regulatory function of the salivary glands is to produce hormones: growth factors, parotin. Renin, erythropoietin, and kallikrein were also found in the salivary glands.

Saliva constituents: enzymes, inorganic substances, cations, microelements, proteins. All types of salivary glands are involved in the production of secretions that form saliva. In the oral cavity, it interacts with other substances, fulfilling its functional purpose.

How much saliva is produced per day?

The body produces about 220 mg of saliva per day, the volume of which may vary due to some factors. Due to nervous overexcitation, the volume of saliva can increase significantly. With age, a person gradually decreases the amount of secretion produced.

During sleep, saliva is produced about 15 times less than during wakefulness. The smell of delicious food that induces appetite also makes a person salivate.

Possible pathologies

Diseases of the salivary glands in most cases are the consequences of trauma:

• the most common injury is a violation of the integrity of the parotid glands, which can also occur as a result of trauma to the carotid artery or facial nerve,
• sialodenitis - inflammation of the salivary glands, which develops against the background of infection,
• sialolithiasis (stone formation) often develops as a complication of sialadenitis. Stones form in the ducts, preventing saliva from flowing out,
• mumps develops against the background of inflammation of the salivary ducts,
• tumor processes.

Causes of inflammatory processes, symptoms

The salivary glands also perform an excretory function.

The reasons for the development of the inflammatory process can be:

• narrowing of the lumen of the excretory duct of the gland,
• diseases of an infectious nature (ARVI, flu, otitis media),
• the formation of a plug in the duct, consisting of leukocytes,
• for musicians playing wind instruments, this can be a complication of their professional activities.

Symptoms:

• the temperature can rise both significantly and to subfebrile levels,
• the salivary gland swells, increases in size,
• there is pain when swallowing and palpation,
• the formation of pus that comes out of the mouth,
• unpleasant odor from the mouth,
• at the site of the inflammatory process, the skin turns red.

Research and diagnostic methods

The examination begins with examination, palpation, questioning of the patient. To assess the state of the salivary glands, special diagnostic methods are used:

• probing allows you to determine the narrowing of the duct, the presence of stones in it, stagnation,
• sialometry makes it possible to determine the volume of saliva secreted and deviations from the norm,
• cytological examination of the secreted secretion makes it possible to identify inflammatory processes and pathogens of pathology,
• radiography,
• An MRI or CT scan can determine the presence of benign and malignant neoplasms, their size and exact location.