The anatomical structure of the oral cavity. The structure and function of the oral cavity of children and adults

The mouth of a living organism is a separate structure that provides nutrition for the normal functioning of all systems and organs. All developed creatures are endowed with the gift of pronouncing various sounds, characteristic of their species. His functional anatomy in humans it is considered the most complex due to the influence of various evolutionary conditions. The oral cavity is a part of the digestive system, protected by the lips, teeth and cheeks on the outside, and inside by the gums.

Departments and structure (diagram) of the oral cavity with a photo

By its structure, the human oral cavity is fundamentally different from the animal: we can eat plant foods, meat, fish. There are several sections of the organ, the main of which is the vestibule of the oral cavity. Understand the features of the structure oral cavity help photo.

The vestibule is the space bounded in front by the lips and cheeks, and behind by the teeth and gums. Its shape and size are extremely important, a small vestibule opens the gate for bacteria to enter.

The upper part is called the palate and the lower part is called the floor of the mouth. The floor of the mouth, as well as the lower wall, is formed by tissue that extends from the insertion of the tongue to the small bone underneath. They are located between the tongue and the hyoid bone. The bottom of the oral cavity ends in the lower part of the diaphragm, which is formed by the paired muscle.

On both sides of the floor of the mouth are three more forming muscles. Below, next to the jaw-hyoid muscle, the base of the digastric muscle is visible. Next, we can observe the muscle cushion of the floor of the mouth.

Musculocutaneous organ - lips

This muscular organ acts as a gateway. The lips have an outer skin with a layer of the epidermis. Its cells are constantly dying off and changing for new ones. The lip is protected from above by the hairs growing on it. The pink intermediate part is located on the border with the mucosa. This part of the labial folds is not capable of keratinization; its cells always remain moist. It is located inside the oral cavity.

Dentition

The teeth in the oral cavity together with the gums strongly affect the vital functions of the body. The development of the oral cavity and dentition begins in the womb. In humans, teeth consist of a root, crown, and neck. The root is hidden in the gum, which is attached from below to the bottom of the oral cavity, and from above to the palate, and has an entrance for the nerve and blood vessels. There are 4 types of teeth that differ in crown shape:

The dental neck is covered by the gum, which can be attributed to mucous surfaces. Why do you need gums? Its value is very great and comes down to keeping the teeth in place. The walls of the gums must always be healthy, otherwise inflammation will penetrate. The development of infectious processes often turns into chronic stage... Its constituent parts:

• interdental papilla;
• gingival margin;
• alveolar site;
• movable gums.

Bridle

The frenum of the tongue is a small fold. It is located below the bottom of the tongue and extends to the bottom of the mouth. On both sides of it there are sublingual folds, similar to small rollers. Due to the presence of the ducts of the salivary glands, they are formed. The bridle is mobile, it can easily gather in small folds. This is due to the fact that it has a weak connection with the surrounding tissues.

Oral mucosa

The organs of the oral cavity are permeated with a network of capillaries, and therefore there is a constant blood supply. In addition, it is rich in salivary glands in the mouth, which protect it from drying out.

Depending on the location, the mucosa may have a keratinized layer (about a quarter of the entire mucosa). Areas without such a layer occupy 60% and another type is referred to as a mixed variant, which accounts for 15% of the surface.

The gums and palate are covered with a mucous membrane capable of keratinization, since they are directly involved in grinding food. Without the ability to coarse, you can find mucous in all parts of the oral cavity, requiring elasticity. Both types of mucosa consist of 4 layers, 2 of which are the same. See below for a diagram of mucosal layers.

When carrying out dental procedures, so that saliva does not flow into a tooth or its wall cleaned of caries, various methods of moisture isolation are used. The most popular are the use of cotton swabs and special suction. The importance of this method cannot be underestimated: the ingress of saliva will lead to a poor-quality installation of the seal and its rapid loss.

Muscles of the mouth

Muscle tissue is divided into 2 types. One is represented by the circular muscle of the floor of the oral cavity, which, when contracted, narrows the cavity space. The rest are located radially and are responsible for expanding the lumen of the pharynx. The circular muscle consists of bundle tissue and is located in the folds of the lips, tightly connects to the skin and participates in the movement of the labial folds.

The zygomaticus muscle extends from the area near the ear. Descending, this muscle of the floor of the mouth connects with the circular and skin in the corner. The small zygomatic muscle originates at the front of the cheekbone.

The medial muscle tissue is intertwined with the zygomaticus major muscle. The tissues of the cheeks are directed forward and connect to the orbicularis muscle of the floor of the mouth, mucous membrane and corners of the lips. Outside there is a fatty layer of the cheek, and inside is a mucous membrane.

There are parotid glands near the front of the masseter muscle. Adequate development of facial muscles provides a person with developed facial expressions. The muscles in the cheeks help to move the corner of the mouth to the side. The muscles of laughter begin from the masseter muscle and from the middle of the upper lip, connecting to the tissues in the corner of the mouth.

The muscle responsible for its downward movement is located in the lower jaw, below the chin. It has a complex structure: it is directed upwards, tapers closer to the corner, connecting with the skin and upper lip. The muscle that helps lower the lower lip is located under the previous one and originates from the front of the lower jaw. Directed upward and connected to the skin of the chin and lower lip.

Heaven and tongue

The sky is top wall the oral cavity, the so-called vault, constantly moistened by the mucous membrane. The sky has 2 parts. Solid sky will separate the oral cavity from the nasopharynx, it is rounded. The soft palate, covered with a special mucous membrane, separates the pharynx, which has a tongue that participates in the process of sound production. The small tongue is shaped like a scapula. The striated muscles give it movement and is also covered with a protective moist layer. The tongue is involved in the grinding of food and the ability to speak. Read more about this in the video clip.

The glands responsible for the production of saliva

The oral cavity contains several differently developed and functioning salivary glands. The glands of the oral cavity are paired and unpaired. The sublingual gland is the smallest. It looks like an ellipse. The parotid salivary gland is one of the largest. It has an asymmetrical shape and is located on the lower jaw, about auricles.

Blood supply and innervation of the maxillofacial region

Blood supply to the brain and cervical produced by the common carotid arteries. The common carotid artery, as a rule, does not form branches. Blood supply goes through paired terminal branches: the internal and external carotid arteries. The bottom is permeated with blood vessels filling from the outer carotid artery... The blood supply to the teeth is due to the maxillary artery.

All mouth organs have nerve endings: 12 paired and 5 nerves connected to the cerebral cortex. The hypoglossal, lingual and maxillary-hypoglossal nerves fit the floor of the mouth. Innervation of the teeth, chewing muscles, skin and the anterior part of the brain creates a ternary nerve. Innervation of the part facial muscles persons carry out facial nerve... Innervation of part of the tongue, pharynx and parotid gland created by the glossopharyngeal nerve. Nervus vagus connected to the sky.

Oral environment

Saliva is a colorless liquid secreted by glands into the oral cavity and has a complex composition. The totality of saliva secreted by all glands is called the oral fluid and its structure is complemented by food particles, various microbes, and elements of tartar are also found. Due to the influence of saliva, taste buds are activated in humans, food is moistened. It also helps to keep the mouth clean due to its antibacterial properties.

Is the environment in our mouth acidic or alkaline? Does adult saliva have a pH of 5.6-7.6? None of the options are correct. The alkaline pH ranges from 7.1 to 14, and the acidic pH ranges from 6.9 to zero. Our saliva has a slightly acidic environment.

The composition of saliva in the oral cavity changes depending on the appearance of any irritating factors. By determining the pH of the saliva in the oral cavity, it is possible to monitor the state of the body.

Relatively constant temperature mouth is 34 - 36 ° C. When measured with a thermometer, the temperature will always be 0.5 - 0.6 degrees higher than under the arm. In children, temperature readings are different from adults and depend on the measurement method.

Oral functions with table

The functions are shown schematically in the table:

Anomalies in the development of the oral cavity

There are many deviations from the norm in medicine, and such manifestations are not uncommon. They appear both on the eve and at the bottom of the mouth. It will be advisable to talk only about the most common anomalies in the development of the oral cavity.

The developmental disorder of the oral cavity leading to a bifurcation of the upper lip is called the cleft lip. This is a characteristic lip separation that is unilateral or bilateral, partially or fully pronounced. As a result of a defect in the structure of the oral cavity, subcutaneous bifurcation occurs.

Anomalies in the development of the oral cavity and face in rare cases is expressed in non-union of the upper lip and palate at the same time, a complete through bifurcation of the lip and palate. There are one-sided and two-sided forms. With this pathology, there is a gap between the cavity and the nose. Often accompanied by Grauhan's disease. Splitting of the upper lip fold, with a pronounced median shape - this pathology is less common than others.

The cleft palate anomaly is otherwise called the cleft palate. It is expressed by a complete bifurcation of the hard and soft palate, or partial, that is, only one part. A through or submucosal bifurcation is also observed.

Anomalies associated with the development of the form of the language are often of two types. A forked tongue, when the cleft is located in the middle, which makes the features of the structure resemble a serpentine. It also occurs in patients with the appearance of a characteristic process that resembles an additional tongue. It is located closer to the bottom of the mouth.

(Greek stoma - mouth, hence dentistry), is divided into two sections: vestibule of the mouth, vestibulum oris, and the oral cavity itself, cavitas oris propria... The vestibule of the mouth is the space between the lips and cheeks on the outside and the teeth and gums on the inside. Through mouth, rima oris, the vestibule of the mouth opens outward.

Lips, labia oris, represent the fibers of the circular muscle of the mouth, covered outside with skin, inside - with a mucous membrane. At the corners of the mouth opening, the lips pass one into the other through adhesions, commissurae labiorum... The skin passes on the lips into the mucous membrane of the mouth, which, continuing from the upper lip to the surface gums, gingiva, forms a fairly well-defined midline bridle, frenulum labii superioris. Frenulum labii inferioris usually subtle. Cheeks, bussae, have the same structure as the lips, but instead of m. orbicularis oris, the buccal muscle is laid here, i.e. buccinator.

Cavitas oris propria extends from the teeth in front and laterally to the entrance to the pharynx from behind. From above, the oral cavity is limited by the hard palate and the anterior region of the soft; bottom is formed diaphragm of the mouth, diaphragma oris (paired m. mylohyoideus) and is busy with the tongue. With the mouth closed, the tongue touches the palate with its upper surface, so that the cavitas oris is reduced to a narrow slit-like space between them. The mucous membrane, passing to the lower surface of the tip of the tongue, forms along the midline frenulum of the tongue, frenulum linguae... On the sides of the bridle, a small papilla, caruncula sublingualis, with an opening on it of the excretory duct of the submandibular and sublingual salivary glands is noticeable. Laterally and posteriorly caruncula sublingulaisstretches from each side p sublingual fold, plica sublingualis, resulting from the sublingual salivary gland located here.

EMBRYOLOGY AND HISTOLOGY OF THE ORAL CAVITY AND TEETH

The structure of the oral cavity

Oral cavity. The mouth gap is limited by the upper and lower lips, passing from the sides to the corners of the mouth. In the red border of the lips, there are external and internal surfaces. The epithelium of the outer surface of the lips has a stratum corneum, which is relatively transparent due to the content of eleidin in the cells. The outer surface of the red border without a sharp border passes into the inner one. IN anterior section the lower lip along the line of closure opens the excretory ducts of the mucous glands (10-12) located deep in the submucous layer (fig.1) .

Figure: 1 Lip structure

(fig.2) In the peripheral part of the outer surface of the lips, mainly in the area of \u200b\u200bthe corners of the mouth, numerous glands are sometimes visible in the form of small yellowish nodules, the excretory ducts of which open on the surface of the epithelium. On the inner surface of the lips along the midline, bridles are attached, passing to the alveolar process of the upper and alveolar parts of the lower jaw. The thickness of the lips is made up of subcutaneous fat and the circular muscle of the mouth.

Figure: 2 Vestibule of the oral cavity

The part of the mucous membrane covering the alveolar process of the upper and alveolar parts of the lower jaw and covering the teeth and the areas of the necks of the teeth is called the gum, which, due to the absence of the submucous layer, is motionlessly fused with the periosteum. At the base of the alveolar process of the upper jaw and the alveolar part of the lower jaw, the mucous membrane is mobile. The area of \u200b\u200bthe mucous membrane of the gums between the movable and fixed part is called the transitional fold. The marginal part of the gum, filling the spaces between the teeth, forms the interdental papillae. The gums are covered with stratified squamous epithelium, which has a stratum corneum in the most injured areas. No glands were found in the gums (fig.3).

Figure: 3 Oral cavity

Cheeks. In the thickness of the cheek, there is adipose tissue and bundles of the buccal muscle. In the submucosal layer of the cheeks, there are a large number of mucous and mixed glands, which are located mainly along the line of closing the teeth. In the posterior part of the cheeks, under the layer of epithelium, numerous small glands are sometimes visible (Fordyce's field).

Figure: 4 Inner cheek area

(fig. 4)On the inner surface of the cheeks with an open mouth in the area of \u200b\u200bthe crown of the second molar of the upper jaw, an elevation of the mucous membrane in the form of a papilla is projected, at the apex of which or under it the excretory duct of the parotid salivary gland opens.

The space limited on one side by the cheeks, and on the other by the alveolar processes and teeth, is called the vestibule of the oral cavity.

In the posterior part, the pterygoid fold separates the oral cavity from the pharynx.

Solid sky... In the anterior part of the hard palate, the transverse folds of the mucous membrane are symmetrically located. In front of them, along the midline in the direction of the necks of the central incisors, there is a thickening of the mucous membrane - the incisal papilla.

In the area of \u200b\u200bthe palatine suture, there is a longitudinal bone eminence (torus).

The mucous membrane of the gums and hard palate is motionless, since it does not have a submucous layer.

In the posterolateral areas of the hard palate, in the submucous layer, there is a large accumulation of adipose and lymphoid tissue. The mucous membrane of the hard palate is covered with epithelium, which tends to keratinization.

On the border with the soft palate, on the sides of the palatine suture, there are often symmetrical slit-like depressions (palatine fossae) into which the excretory ducts of the mucous glands open (fig. 5).

Figure: 5 Sky region

Soft sky... It is a muscular plate covered with a mucous membrane. The surface of the soft palate facing the nasopharynx is lined with multi-row ciliated epithelium. The protrusion of the soft palate along the midline is called the uvula (palatine). On the sides of the soft palate, there are two folds - the palatine-lingual and the palatopharyngeal, between which there is an accumulation of lymphoid tissue - the pharyngeal tonsil.

The submucous layer of the soft palate contains a large number of mucous and mixed glands (fig. 6).

Figure: 6 Pharynx area

The bottom of the mouth is occupied by the tongue. In the sublingual region, the mucous membrane forms a series of folds. In the anterior section along the midline, there is a fold that runs from the alveolar process to the lower surface of the tongue (frenum of the tongue). On the sides of the bridle, small elevations are noted, at the top of which the excretory ducts of the submandibular and sublingual salivary glands open (fig. 7).

Tongue... It is a muscular organ covered with a mucous membrane. Distinguish between the back, wider section (root of the tongue), the middle part (body of the tongue) and the tip (top of the tongue). The mucous membrane of the tongue has a rough, villous surface, in which the papillae lie: filiform, mushroom, leaf-shaped and surrounded by a roller.

Filiform papillae evenly distributed over the entire back of the tongue. The superficial epithelial cells of these papillae are partially keratinized, which gives the tongue a whitish tint.

Mushroom papillae look like red dots, located mainly in the region of the apex of the tongue; they have a narrow base and a wider top. The epithelium covering them is not keratinized and contains a large number of taste buds.

Papillae located in the posterolateral parts of the tongue in the form of 3 - 8 transverse folds, separated by narrow grooves. The epithelium of the leaf-shaped papillae contains taste buds.

Grooved papillae (papillae surrounded by a shaft) are located on the border of the root and body of the tongue in the form of the Roman numeral V, contain a large number of taste buds, the excretory ducts of the protein glands open into the epithelium covering them. Behind the papillae, surrounded by a shaft, and located here in the midline of the blind opening of the tongue, the mucous membrane has a tuberosity due to the lymphoid tissue of which it consists lingual tonsil, located in the submucosal layer (fig. 8).

Figure: 8 Language

On the lower surface of the tongue, on the sides of the frenum, there are symmetrical thin fringed folds, as well as a clearly contoured pattern blood vessels... In the thickness of the muscle tissue of the tip of the tongue, there are paired anterior glands, the excretory ducts of which open with pinpoint holes. On the lower lateral surface of the tongue in front of the leaf-shaped papillae, the lateral glands are localized (fig. 9).

Figure: 9 Language(side view)

The structure of the oral mucosa... The mucous membrane of the mouth consists of three layers: the epithelium, the mucous membrane itself, the submucosa.

Epithelium. The mucous membrane of the mouth is lined with stratified squamous epithelium, the thickness of which is 200-500 microns. It consists of several layers of cells of different shapes, closely interconnected by intercellular bridges; tonofibrils pass through these bridges, which, fastening the cells together, like a zipper, determine the mechanical strength and elasticity of the epithelial layer.

According to the shape of the cells and their relation to dyes, several layers are distinguished in the epithelium: basal, subulate, granular, horny.

Areas of the oral mucosa epithelium exposed to the greatest mechanical stress (hard palate, gums, back of the tongue, lips) show signs of keratinization.

A layer of its own mucous membrane. This layer consists of dense connective tissue permeated with collagen and elastic fibers, and forms protrusions towards the epithelium (connective tissue papillae), in which capillaries pass and nerve receptors are embedded.

Without a clear border, it passes into the submucous layer, consisting of looser connective tissue. In some areas of the oral cavity (tongue, gums, hard palate), the submucosa is absent, and the mucous membrane is directly adhered to the intermuscular connective tissue or periosteum and relatively motionless.

DEVELOPMENT OF THE TOOTH.

Three periods are distinguished during the development of teeth:

laying and formation of tooth germs;

differentiation of tooth germs;

histogenesis of dental tissues.

Teething of the crown of a milk tooth.

Baby teeth erupt at 6 - 7 months of a child's life. By the time a tooth erupts, its crown is fully developed. The development of the root and its final formation occurs after the eruption of the crown. For deciduous teeth, this is done within 1.5-2 years, for permanent teeth - 3-4 years.

In the light of modern ideas, teething is caused by many external and internal factors and is closely related to the general condition of the child.

Immediately before eruption, a small protrusion of the mucous membrane (mound) is formed at the apex of the alveolar process in the corresponding place of this process.

Subsequently, the epithelium of the tooth germ comes into contact with the mucous membrane of the alveolar process, which becomes thinner and breaks through at the top of the tubercles or the incisal edge of the erupting tooth. It is believed that the epithelium of the future gum grows together with the epithelium of the dental organ and, after eruption of the tooth, remains on the surface of its crown in the form of a thin structureless shell - the enamel cuticle.

After the eruption of the crown in the area of \u200b\u200bthe tooth neck, the gum epithelium grows together with the enamel cuticle, forming an epithelial attachment. The slit-like depression between the crown of the tooth and the gum is called the physiological dentogingival groove.

Teething of deciduous teeth occurs at a certain time and in a strict sequence, mainly in corresponding pairs, namely:

During the eruption permanent tooth the bone tissue of the alveoli, which separates the root of the temporary tooth, gradually dissolves. The so-called resorbing organ, which consists of young connective tissue with a large number of multinucleated giant cells (osteoclasts) and lymphocytes, takes an active part in the resorption process. Then the gradual resorption of the root of the milk tooth begins. Root resorption occurs asymmetrically in the form of gaps, niches, primarily in the areas of contact between the crown of a permanent tooth and a temporary root.

The roots of incisors and canines are absorbed to a greater extent from the lingual, molars - from the inter-root surface. At the same time, in the upper temporary molars, the buccal roots dissolve faster, in the lower ones, the posterior (distal) root. It is assumed that the pulp of the milk tooth is also actively involved in the resorption of the root, which by this time turns into granulation tissue.

By the time a permanent tooth erupts, the root of the temporary one almost completely disappears, and its crown loses its support and is, as it were, pushed out by the permanent tooth.

After the crown of a deciduous tooth has fallen out, tubercles or incisal edges of the corresponding permanent tooth can usually be found in the dental alveolus.

Eruption of the crown of a permanent tooth.

This process is considered complete only after the extension of the crown into the oral cavity, which is accompanied by the formation of a physiological periodontal groove.

The timing and sequence of the eruption of permanent teeth are as follows:

The eruption of the teeth of the lower jaw of both temporary and permanent bite is somewhat ahead of the eruption of the corresponding teeth of the upper jaw.

Content of the article: classList.toggle () "\u003e expand

The oral cavity (cavum oris) is the initial part of the digestive tract, in which the chemical and mechanical processing of food takes place. The oral cavity is opened in front by the oral slit, from behind it communicates with the pharynx.

The structure of the oral cavity

Anatomically, the mouth consists of the following parts: lips, cheeks, gums, teeth, tongue, palate, uvula, tonsils. The uvula (plays a role in the formation of sounds) and tonsils (perform protective and hematopoietic functions) do not play a role in digestion.

The oral cavity consists of the vestibule and the oral cavity itself. The vestibule is limited by the upper and lower lip, as well as by the teeth. The main function of this department is to capture and hold food. Directly the oral cavity in front is bounded by the teeth, on the sides - by the cheeks, below - by the muscles of the diaphragm of the mouth, above - by the hard and soft palate. The palatine uvula is a conditional border between the oral cavity and the oropharynx.

The mucous membrane of the oral cavity is equipped with a huge number of small glands, which are actively involved in the formation of saliva.

Lips - musculocutaneous grooves, in which the following areas are distinguished:

• Skin - located on the outer, visible side, covered with a layer of keratinized epithelium, there are ducts on it that produce sebum, provide sweating;
• Intermediate - an area covered with pink skin. The segment (border), where the transition of the skin to the mucous membrane occurs, is brightly colored in red, this zone is supplied a large number blood vessels, nerve plexuses, is a sensitive area;
• Mucous membrane - located on the inner surface of the lips, covered with squamous epithelium.

Cheeks - symmetrical zone, composed of the buccal muscle, which is covered by the skin and contains the fatty body.

Gum - consists of mucous membranes; the gum is divided into several parts:

• Free (marginal) - smooth mucous, encircling the dental neck;
• Gingival groove - located between the gum and the tooth;
• Interdental papilla - localized between adjacent teeth;
• Attached (alveolar) - immovable gum area, grows together with the dental root and periosteum.

Teeth - participate in grinding food; in adulthood, 28–32 teeth are present. The tooth consists of a crown, which is covered with enamel (it consists of a mineral substance, in particular calcium and phosphorus salts, is devoid of sensitivity), a neck and a root.

Under the enamel is dentin - a light solid yellow color, similar to bone, it protects the tooth from mechanical damage... Inside there is a pulp chamber, which is filled with connective tissue (pulp), it supplies the tooth nutrients... Depending on the function, teeth are divided into the following types:

• Fangs (eye teeth) - tear food into tiny pieces;
• Incisors - for biting food;
• Large and small molars (molars, premolars) - grind, grind food.

Teeth differ in appearance due to the different structure of the crown. In incisors, it flattens at the top and has a cutting edge, as a result of which the main purpose of incisors is to bite off food. In canines, the crown is usually triangular and pointed, and therefore, the main purpose of these teeth is to capture and hold food.

Teeth are a very important part digestive system, on which the speed and quality of assimilation of nutrients largely depends.

Each tooth has three parts:

• Crown - part of the tooth protruding above the gum;
• The neck is a somewhat narrowed part, which is located at the border of the transition of the crown to the root;
• The root is the part of the tooth that is located in the alveolar cell of the jaw (a special depression in the bone for the tooth).

- muscle formation pink and spatulate, almost completely fills the mouth. On the upper part there are taste buds (mushroom, leaf-shaped, grooved), which look like a small elevation above the surface.

Filamentous give the tongue a peculiar velvety appearance and act as sensitive receptors.

And mushroom-shaped and grooved, in fact, they are taste buds, thanks to which we feel food and distinguish sour from salty, sweet from bitter.

The tongue takes part in the chewing process, salivation, taste assessment, provides a person with articulate speech. It is noteworthy that after the interaction of food with taste buds, motor-secretory activation of the entire digestive tract occurs.

Main areas of the language:

• Root - makes up 1/3 part;
• Body - 2/3, located near the teeth;
• Apex - bordered by the posterior surface of the incisors;
• Back - outer surface;
• Frenum - connects the floor of the mouth and lower part language.

May indicate various diseases.

Taste receptors are distributed over the surface of the tongue in a special way, so that each of its sections is responsible for the perception of a specific type of taste sensitivity:

Sky - the upper zone of the mouth, divided into 2 areas: soft and hard palate. The soft palate is a slimy furrow that hangs over the root of the tongue, separating the mouth and pharynx. There is a tongue on it, which is involved in the reproduction of sounds, closes the entrance to the nasopharynx. Solid sky - bone structure, separates the oral cavity and nasopharynx.

Salivary glands belong to the exocrine ducts, they secrete a secret called saliva. The average amount of saliva that a person produces per day is one and a half to two liters.

The following large paired salivary glands are shared:

• The parotid is the largest gland, irregular in shape, grayish-pink in color. The duct is localized on the lateral surface of the lower jaw below the auricles. The saliva produced is highly acidic, saturated with potassium and sodium chloride;
• The sublingual is a small oval-shaped gland, located at the bottom of the oral cavity on the sides of the tongue. The secreted saliva has a high alkaline activity, saturated with serous secretions and mucin;
• Submandibular - the size of walnut, rounded, located in the submandibular triangle. The saliva produced contains serous and mucous secretions.

Saliva is 99% water and 1% dry matter, which is represented by the following elements:

• Inorganic compounds such as phosphates, chlorides, sulfates, calcium, potassium, sodium ions;
• Organic protein complexes:
  • Lysozyme: imparts bactericidal properties to saliva, due to which it inactivates some bacterial agents;
  • Mucin: has enveloping properties and facilitates the passage of the food bolus into the oropharynx and esophagus;
  • Maltase and Amylase: These are digestive enzymes that are capable of breaking down carbohydrate compounds.

Based on the composition of saliva, its main functions can be distinguished:

• Takes part in the digestion of carbohydrates;
• Envelopes the food lump, making it comfortable to swallow;
• Trophic function. Inorganic compounds of saliva serve as a source for the formation and strengthening of tooth enamel;
• Suppression of bacterial agents, i.e. protective function.

Normal teeth Questions and answers Functions and structure of the human oral cavity

The process of digesting food begins in the mouth. It is in the human mouth that food acquires the temperature and consistency necessary for its further processing. The oral cavity has interesting building and performs a number of important functions.

The structure of the oral cavity

The mouth consists of the vestibule and the oral cavity. The vestibule is limited to the lips and teeth and performs the functions of grasping and biting off food. The oral cavity in its front part is bounded by the teeth, on the sides - by the cheeks, from above - by the palate, from below - by muscles.

Lips

Lips are a musculocutaneous organ.

The lips are the vestibule of the mouth, the musculocutaneous organ. With the help of the upper and lower lips, we grab and hold food, after which it goes directly into the mouth. Lip structure:

• external part of the lips consists of keratinized epithelium, here are the ducts responsible for the production of sebum for perspiration,
• intermediate part - this is the very border of a pale pink color, the transition of the skin to the mucous membrane. It is a sensitive area with a large number of blood vessels and nerve endings,
• mucous - the inside of the lips.

The cheeks are made up of the cheek muscles containing the fatty body and covered with skin.

The gums are covered with mucous membranes. Desna consists of several departments:

• loose mucosa surrounds the neck of the tooth,
• gingival sulcus - the area between the tooth and the gum,
• the interdental papilla is located between adjacent teeth,
• alveolar mucosa is a fixed area of \u200b\u200bthe gum that grows together with the root and periosteum.

Teeth

The teeth are directly involved in biting off and grinding food. The upper part of the tooth is a crown covered with enamel (composed of phosphorus and calcium salts). Then the crown goes into the neck and root.

Under the enamel is a layer of dentin, a yellow substance that protects the tooth from external damage. Inside the tooth there is a pulp - this is a bundle of nerve endings and blood vessels, it is she who supplies the tooth with the useful substances necessary for its normal functioning.

Teeth are divided into several types depending on their functional purpose:

The teeth differ from each other in the structure of the crown, appearance... Teeth play an important role in digestion, as the quality of chopping food and the subsequent absorption of nutrients by the body depends on them.

Mucous membrane

The entire human oral cavity is covered with a mucous membrane, which performs a protective function. In the area of \u200b\u200bthe cheeks, lips and the lower part of the mouth, the mucous membrane is collected in folds, and in the upper part, on the contrary, it is stretched and firmly fixed on the bone tissue. The oral mucosa performs a number of functions:

• Protective... In the oral cavity there is always a large number of various pathogenic microorganisms, which, under favorable conditions for them, provoke the development of dental diseases. The mucous membrane retains the infection and removes it with the help of saliva,
• Sensitive... Thanks to sensory, heat and taste receptors, the mucous membrane acts in the body as a kind of indicator,
• Suction... The mucous membrane absorbs protein and mineral compounds. This is why some medications it is recommended to dissolve or retain in the mouth.

Muscle

The upper jaw is motionless, only the lower jaw moves, several muscles help it in this: the chewing, temporal, medial pterygoid. The lateral pterygoid muscle is responsible for forward movement. Goes down lower jaw with the help of the jaw-hypoglossal and sublingual muscles.

The fibers of the circular muscles are located in the tissues of the lips, the task of which is to ensure the opening-closing of the mouth and the extension of the lips forward. The cheek muscles are located in the cheeks. The tongue contains several types of muscles that are responsible for its movements when swallowing, chewing and articulating.

Tongue and palate

The tongue is a muscular organ that fills almost the entire oral cavity. On top are taste buds, which are of several types:

• filamentous - sensitive receptors, thanks to them the tongue has a velvety appearance,
• mushroom and grooved - these are taste buds, with the help of which a person feels the taste of food and drinks.

The tongue takes part in chewing food, articulation, salivation, and taste perception. Interestingly, after the food contacts the taste buds, the entire digestive tract... Parts of the tongue: root, body, tip, back, frenum.

The taste buds are located on the tongue in such a way that the organ is divided into sections, each of which is responsible for the perception of a specific taste.

The tongue is responsible for articulating, chewing and swallowing food.

The palate is top part mouth, which separates it from the nasopharynx. The palate is divided into soft and hard. It is the hard palate that separates the oral cavity from the nasopharynx.

Microflora

As part of microflora healthy person bacteria predominate, while fungi and viruses are present in smaller numbers. The bulk of bacteria are streptococci and lactobacilli. For some disorders in the body and favorable conditions the infection can penetrate into the mouth and provoke the development of various dental diseases.

Salivary glands

The salivary glands are responsible for the production of saliva, a special secretion involved in the digestion of food. This is a paired organ. The salivary glands are divided into several types:

Saliva is 99% water, 1% is:

1. Inorganic substances (chlorides, phosphates, sulfates),
2. Organic compounds:

• lysozyme helps saliva to eliminate pathogenic microorganisms that enter the oral cavity,
• mucin provides an enveloping property to saliva, which allows the food lump to move along the oropharynx into the esophagus,
• amylase and maltase are enzymes that break down carbohydrate compounds.

Saliva functions: digestion of carbohydrates, formation of a food lump, strengthening of enamel, suppression of pathogenic agents.

Oral functions

Let's summarize. Based on the foregoing, it can be concluded that the human oral cavity performs a number of vital functions for the body:

1. Digestive.

It is in the mouth that the digestion process begins. The quality of its further digestion depends on the quality of grinding food with teeth. That is why, with the loss of a large number of teeth, serious problems with the gastrointestinal tract must develop. Teeth, tongue, saliva take part in food processing.

For problems with natural nasal breathing, as well as for severe physical activity a person has the ability to breathe through the mouth. But the physiological and correct breathing for the body is through the nose. Therefore, the restoration of nasal breathing is very important for the normal functioning of the whole organism.

1. Speech.

The quality of pronunciation and articulation depends on the structure of the human oral cavity. These are the features of the bite, the location of the teeth, bridles, tongue.

1. Analytical room.

The receptor apparatus of the mouth is connected with the digestive tract, the brain. In the oral cavity, food is analyzed according to the parameters: taste, temperature, tactile sensitivity. Receptors transmit the received information via nerves to the central nervous system.

1. Protective function.

The high regenerative capacity of the epithelium provides reliable protection against many damaging external factors... A good blood supply to the mouth ensures fast healing mucous membrane when it is damaged. IN salivary glands special compounds are produced that destroy pathogenic microorganisms and prevent their penetration into the body.