Functions and structure of the oral cavity

The mouth of any living creature is a complex biomechanical system, providing it with food, and hence existence. In higher organisms, the mouth, or, to put it scientifically, the oral cavity, carries an additional important load - sound production. The structure of the human oral cavity is the most complex, which was influenced by communication functions and a number of features related to the development of the human body.

Structure and function of the oral cavity

In all living organisms, including humans, the mouth is the first department of the digestive system. This is his most important and common function for most creatures, no matter what form nature has come up with. In humans, it is a gap that can open wide. With the mouth we grab or take food, hold it, crush it, moisten it with plenty of saliva, and push it into the esophagus, which in fact is a hollow tube through which food slips into the stomach for processing. But the beginning of digestion begins already in the mouth. That is why the ancient philosophers said how many times you will spend, you will live for so many years.

The second function of the mouth is the pronunciation of sounds. Man not only publishes them, but also unites them in complex combinations. Therefore, the structure of the oral cavity in humans is much more complicated than that of our smaller brothers.

The third function of the mouth is participation in the process of breathing. Here it is his job to only take portions of air and transmit them to the respiratory tract, when for some reason the nose can not cope with it and partly during the conversation.

Anatomical structure

We daily use all parts of the mouth, and some of them even repeatedly contemplate. In science, the structure of the oral cavity is specified. The photo clearly shows what it is.

Physicians in this body distinguish two departments, called the vestibule of the mouth and actually its cavity.

On the eve there are external organs (cheeks, lips) and internal (gums, teeth). So to speak, the entrance to the mouth is called the oral slit.

The oral cavity itself is a kind of space, limited on all sides by organs and their parts. Bottom is the bottom of our mouth, the top of the palate, the front of the gums, and also the teeth, behind the tonsils, which are the border between the mouth and throat, on the sides of the cheek, in the center of the tongue. All internal parts of the oral cavity are covered with a mucous membrane.

Lips

This body, which so much attention is paid to the weaker sex to rule the strong sex, in fact, is a pair of muscular folds surrounding the mouth slit. In humans, they participate in the retention of food entering the mouth, in sound formation, in mimic movements. Isolate the upper and lower lips, the structure of which is approximately the same and includes three parts:

- Outer - covered with keratinous planar multilayered epithelium.

- Intermediate - has several layers, the outer one of which is also horny. It is very thin and transparent. Through it the capillaries perfectly permeate, which determines the pinkish-red color of the lips. Where the horny skin layer passes into the mucous membrane, a lot of nerve endings are concentrated (several dozen times more than at the fingertips), so the lips of a person are unusually sensitive.

- Mucous, occupying the back of the lips. It has many ducts of the salivary glands (labial). Cover it with a nonkeratinized epithelium.

The mucous lip passes into the mucous gum to form two longitudinal folds, called the bridles of the upper lip and the lower one.

The border of the lower lip and chin is the horizontal chin-labial furrow.

The border of the upper lip and cheeks are nasolabial folds.

Between themselves, lips are joined at the corners of the mouth by lip adhesions.

Cheeks

The structure of the oral cavity includes a paired organ, all known as cheeks. They are divided into right and left, each has an external and internal parts. The outer is covered with a delicate, delicate skin, the inner non-coronary mucosa, which passes into the mucous gum. Also in the cheeks is a fat body. In infants, it plays an important role in the sucking process, so it is developed significantly. In adults, the fatty body flattenes and shifts backwards. In medicine, he is called the fatty lump of Bish. Cheek muscles are the basis of the cheeks. The gland in the submucosa is small. Their ducts open in the mucous membrane.

Sky

This part of the mouth is inherently a septum between the oral cavity and the nasal, as well as between the nasal part of the pharynx. The functions of the palate are basically just the formation of sounds. In chewing food it participates slightly, as it has lost clear expression of transverse folds (in infants they are more noticeable). In addition, the palate enters the articulatory apparatus, which provides bite. Distinguish between the palate and soft.

On a solid account for 2/3 of the part. It is formed by the plates of the palatines and the processes of the maxillary bones fused together. If for some reason the splice does not occur, the baby is born with an anomaly called the wolf mouth. In this case, the nasal and oral cavities are not separated. Without specialized care, such a child dies.

Mucous in normal development should fuse with the upper palate and smoothly move to the soft palate, and then to the alveolar processes in the upper jaw, forming the upper gums.

On the soft palate is only 1/3 of the part, but it has a significant effect on the structure of the mouth and throat. In fact, the soft palate is a specific pleat of the mucous, like a curtain hanging over the root of the tongue. It separates the mouth from the pharynx. In the center of this "curtain" is a small outgrowth called a tongue. It helps to form sounds.

From the edges of the "curtain" are the front arch (palate-lingual) and the posterior (palate-pharyngeal). Between them there is a hole where the accumulation of cells of lymphoid tissue (palatine tonsil) is formed. At 1 cm from it is located carotid artery.

Language

This body performs many functions:

- chewing (in infants sucking);

- sound-forming;

- salivating;

- perceiving taste.

The shape of a person's tongue is influenced not by the structure of the oral cavity, but by its functional state. In the language, a root and a body with a back are selected (the side facing the palate). The body of the tongue crosses the longitudinal groove, and in the place of its connection with the root lies a transverse groove. Under the tongue is a special fold, called a bridle. Near it are channels of the salivary glands.

The mucous membrane is covered by a multilayered epithelium, in which taste receptors, glands and lymphomas are located. Upper, tip and lateral parts of the tongue are covered with dozens of papillae, divided into mushroom-shaped, filiform, conical, leaf-shaped, grooved. At the root of the tongue there are no papillae, but there are clusters of lymphatic cells that form lingual tonsils.

Teeth and gums

These two interconnected parts have a great influence on the features of the structure of the oral cavity. Teeth in humans begin to develop at the embryo stage. The newborn in each jaw has 18 follicles (10 milk teeth and 8 molars). They are arranged in two rows: labial and lingual. The rule is the appearance of baby teeth, when the baby was 6 to 12 months old. Age, when the norm of the milk teeth fall, even more stretched - from 6 years to 12. Adults should have 28 to 32 teeth. The smaller number negatively affects the processing of food and, as a consequence, the work of the digestive tract, since it is the teeth that play the main role in chewing food. In addition, they participate in the correct sound formation. The structure of any of the teeth (indigenous or dairy) is the same and includes the root, crown and neck. The root is in the dental alveolus, at the end has a tiny hole through which the veins, arteries and nerves pass through the tooth. A person has formed 4 varieties of teeth, each of which has a certain shape of the crown:

- incisors (in the form of a bit with a cutting surface);

- fangs (cone-shaped);

- premolars (oval, has a small chewing surface with two tubercles);

- large root (cubic with 3-5 tubercles).

Cervical teeth occupy a small area between the crown and root and are covered by the gums. At its core gums are mucous membranes. Their structure includes:

- the interdental papilla;

- Gingival margin;

- alveolar area;

- a mobile gum.

The gums consist of multilayered epithelium and lamina.

They are based on a specific stroma, consisting of a variety of collagen fibers, which ensure a tight fit of the mucosa to the teeth and the proper chewing process.

Microflora

The structure of the mouth and oral cavity will not be fully disclosed, if we do not mention the billions of microorganisms for which, during evolution, the human mouth has become not just a house, but an entire universe. Our oral cavity is attractive for the smallest bioforms, thanks to its following features:

- stable, moreover, the optimum temperature;

- constantly high humidity;

- slightly alkaline medium;

- practically constant availability of nutrients in free access.

Babies are born with microbes in the mouth, which are moved there from the birth canals of women in childbirth for the shortest time, while newborns pass them. Further colonization moves with astonishing speed, and after a month of germs in the mouth of the child there are several dozen species and millions of individuals. In adults, the number of microbial species in the mouth varies from 160 to 500, and their number reaches billions. Not the least role in such a large-scale settlement is played by the structure of the oral cavity. Only teeth (especially sick and unclean) and almost constantly present on them dental plaque contain millions of microorganisms.

Among them, the prevalence of bacteria, the leader among which are streptococci (up to 60%).

In addition to them, fungi (mainly candida) and viruses live in the mouth.

Structure and function of the oral mucosa

The penetration of pathogenic microbes into the tissues of the oral cavity is protected by the mucous membrane. This is one of its main functions - the first to take on the impact of viruses and bacteria.

It also covers the tissues of the mouth from the effects of unfavorable temperatures, harmful substances and mechanical injuries.

In addition to protective, the mucosa performs another very important function - the secretory one.

Features of the structure of the oral mucosa are such that glandular cells are located in its submucosa. Their clusters form small salivary glands. They continuously and regularly moisturize the mucous membrane, ensuring that it performs protective functions.

Depending on which parts the mucous membrane covers, it can be with a keratinized surface layer or epithelium (25%), with non-keratinizing (60%) and with mixed (15%).

The horny epithelium covers only the solid palate and gums, because they participate in chewing and interact with solid food fragments.

The non-cornificating epithelium covers the cheeks, soft palate, its outgrowth is the tongue, that is those parts of the mouth that need flexibility.

The structure of both epithelia includes 4 layers. The first two of them, basal and prickly, are in both.

The cornified layer occupies the horny third position, and the fourth horny (there are cells without nuclei in it and almost no leukocytes).

In the non-heathing, the third layer is intermediate, and the fourth layer is superficial. There is a congestion of leukocyte cells, which also affects the protective functions of the mucosa.

Mixed epithelium covers the tongue.

The structure of the oral mucosa has other features:

- Absence of a muscular plate in it.

- Absence in some parts of the oral cavity of the submucosa, that is, the mucosa lies directly on the muscles (observed, for example, in the tongue), or directly on the bone (for example, on the hard palate) and firmly fuses with the underlying tissues.

- The presence of multiple capillaries (this gives the mucous characteristic reddish color).

Structure of the oral cavity in children

During the life of a person, the structure of his organs changes. Thus, the structure of the oral cavity of children before the year differs significantly from its structure in adults, and not only by the absence of teeth, as mentioned above.

The primary mouth of the embryo is formed in the second week after conception. In newborns, as everyone knows, there are no teeth. But this is not the same as the absence of teeth in the elderly. The fact is that in the oral cavity of babies teeth are in the state of rudiments, and, simultaneously, both dairy and permanent. At some point they will appear on the surface of the gums. In the oral cavity of the elderly, the alveolar processes themselves are already atrophied, that is, there are no teeth and will not. All parts of the mouth of a newborn are created by nature so as to ensure the process of sucking. Distinctive differences that help to grip the nipple:

- Soft lips with a specific labial pillow.

- A relatively well developed circular muscle in the mouth.

- Grassy membrane with a lot of tubercles.

- Transverse folds in the solid palate are clearly defined.

- The position of the lower jaw is distal (the baby pushes his lower jaw, and makes it move back and forth, not in the sides or in a circular manner, as in chewing).

An important feature of babies is that they can swallow and simultaneously breathe.

The structure of the oral mucosa of infants is also different from adults. Epithelium in children under one year consists only of basal and spine-like layers, and the epithelial papillae are very poorly developed. In the connective layer of the mucosa there are protein structures transmitted from the mother along with immunity. Adulthood, the baby loses its immune properties. This also applies to the tissues of the oral mucosa. In the future, the epithelium thickens in it, the amount of glycogen on the hard palate and gums decreases.

By three years in children, the oral mucosa has more distinct regional differences, the epithelium acquires the ability to coronate. But in the connective layer of the mucosa and near the blood vessels there are still many cellular elements. This promotes increased permeability and, as a consequence, the occurrence of herpetic stomatitis.

By age 14, the structure of the oral mucosa in adolescents is not much different from adults, but against the background of hormonal changes in the body they may have mucosal diseases: mild leukopenia and juvenile gingivitis.