Anatomical and physiological features of the respiratory system in children. Clinical significance

The formation of the tracheopulmonary system begins at 3-4 weeks embryonic development. Already by the 5-6th week of embryo development, second-order branches appear and the formation of three lobes is predetermined right lung and two lobes of the left lung. During this period, a trunk is formed pulmonary artery, growing into the lungs along the primary bronchi.

In the embryo, at the 6-8th week of development, the main arterial and venous collectors of the lungs are formed. Within 3 months, the bronchial tree grows, segmental and subsegmental bronchi appear.

During the 11-12th week of development, areas of lung tissue are already present. They, together with the segmental bronchi, arteries and veins, form the embryonic segments of the lungs.

Rapid growth is observed between 4 and 6 months vascular system lungs.

In fetuses at 7 months, the lung tissue acquires the features of a porous canal structure; the future air spaces are filled with fluid, which is secreted by the cells lining the bronchi.

At 8-9 months of the intrauterine period, further development of the functional units of the lungs occurs.

The birth of a child requires the immediate functioning of the lungs; during this period, with the onset of breathing, significant changes occur in the airways, especially the respiratory part of the lungs. The formation of the respiratory surface in individual parts of the lungs occurs unevenly. For the management of the respiratory apparatus of the lungs, the condition and readiness of the surfactant film lining the lung surface are of great importance. Violation of the surface tension of the surfactant system leads to serious illnesses in the child early age.

In the first months of life, the child maintains the ratio of the length and width of the airways, like a fetus, when the trachea and bronchi are shorter and wider than in adults, and the small bronchi are narrower.

The pleura covering the lungs in a newborn baby is thicker, looser, contains villi and outgrowths, especially in the interlobar grooves. Pathological foci appear in these areas. Before the birth of a child, the lungs are prepared to perform the respiratory function, but individual components are in the development stage, the formation and maturation of the alveoli is rapidly proceeding, the small lumen of the muscular arteries is being reconstructed and the barrier function is being eliminated.

After three months of age, period II is distinguished.

1. period of intense growth pulmonary lobes(from 3 months to 3 years).
2. final differentiation of all bronchopulmonary system(from 3 to 7 years).

Intensive growth of the trachea and bronchi occurs in the 1st–2nd year of life, which slows down in subsequent years, and the small bronchi grow intensively, and the branching angles of the bronchi also increase. The diameter of the alveoli increases, and the respiratory surface of the lungs doubles with age. In children under 8 months, the diameter of the alveoli is 0.06 mm, in 2 years - 0.12 mm, in 6 years - 0.2 mm, in 12 years - 0.25 mm.

In the first years of life, growth and differentiation of elements occur lung tissue, vessels. The ratio of the volumes of shares in individual segments is equalized. Already at 6-7 years of age, the lungs are a fully formed organ and are indistinguishable from the lungs of adults.

Peculiarities respiratory tract baby

The respiratory tract is divided into upper, which includes the nose, paranasal sinuses, pharynx, Eustachian tubes, and lower, which includes the larynx, trachea, bronchi.

The main function of breathing is to conduct air into the lungs, cleanse it of dust particles, protect the lungs from harmful effects bacteria, viruses, foreign particles. In addition, the airways warm and humidify the inhaled air.

The lungs are represented by small sacs that contain air. They connect with each other. The main function of the lungs is to absorb oxygen from the atmospheric air and release gases into the atmosphere, primarily acid coal.

Breathing mechanism. When inhaling, the diaphragm and chest muscles contract. Exhalation in older age occurs passively under the influence of elastic traction of the lungs. With bronchial obstruction, emphysema, and also in newborns, active inhalation occurs.

Normally, breathing is established at a frequency at which the volume of breathing is performed due to the minimum energy expenditure of the respiratory muscles. In newborn children, the respiratory rate is 30-40, in adults - 16-20 per minute.

The main carrier of oxygen is hemoglobin. In the pulmonary capillaries, oxygen binds to hemoglobin, forming oxyhemoglobin. In newborns, fetal hemoglobin predominates. On the first day of life, it is contained in the body about 70%, by the end of the 2nd week - 50%. Fetal hemoglobin has the ability to easily bind oxygen and difficult to release it to tissues. This helps the child in the presence of oxygen starvation.

Transport carbon dioxide occurs in dissolved form, oxygen saturation of the blood affects the carbon dioxide content.

The respiratory function is closely related to the pulmonary circulation. This is a complex process.

During breathing, autoregulation is noted. When the lung stretches during inhalation, the inhalation center is inhibited, and exhalation is stimulated during exhalation. Deep breathing or forced inflation of the lungs leads to a reflex expansion of the bronchi and increases the tone of the respiratory muscles. When the lungs collapse and are compressed, the bronchi become narrowed.

The medulla oblongata contains the respiratory center, from where commands are sent to the respiratory muscles. The bronchi lengthen when you inhale, and shorten and narrow when you exhale.

The relationship between the functions of breathing and blood circulation appears from the moment the lungs expand during the first breath of a newborn, when both the alveoli and blood vessels expand.

Respiratory diseases in children may cause problems respiratory function and respiratory failure.

Features of the structure of a child's nose

In young children, the nasal passages are short, the nose is flattened due to an insufficiently developed facial skeleton. The nasal passages are narrower, the conchae are thickened. The nasal passages are fully formed only by the age of 4 years. The nasal cavity is relatively small in size. The mucous membrane is very loose, well supplied blood vessels. The inflammatory process leads to the development of edema and, as a result, a reduction in the lumen of the nasal passages. Mucus often stagnates in the nasal passages. It can dry out, forming crusts.

When the nasal passages close, shortness of breath may occur; during this period, the child cannot suckle at the breast, becomes anxious, abandons the breast, and remains hungry. Children, due to difficulty in nasal breathing, begin to breathe through their mouths, their warming of the incoming air is disrupted and their susceptibility to colds increases.

If nasal breathing is impaired, there is a lack of discrimination of odors. This leads to loss of appetite, as well as a violation of the idea of external environment. Breathing through the nose is physiological, breathing through the mouth is a sign of nasal disease.

Accessory nasal cavities. The paranasal cavities, or sinuses, as they are called, are limited spaces filled with air. The maxillary (maxillary) sinuses are formed by the age of 7. Ethmoidal - by the age of 12, the frontal is fully formed by the age of 19.

Features of the nasolacrimal duct. The nasolacrimal duct is shorter than in adults, its valves are not sufficiently developed, and the outlet is located close to the corner of the eyelids. Due to these features, the infection quickly spreads from the nose to the conjunctival sac.

Features of the pharynxbaby

The pharynx in young children is relatively wide, the palatine tonsils are poorly developed, which explains the rare cases of sore throat in the first year of life. The tonsils are fully developed by the age of 4-5 years. By the end of the first year of life, almond tissue hyperplasias. But its barrier function at this age is very low. Overgrown almond tissue can be susceptible to infection, which is why diseases such as tonsillitis and adenoiditis occur.

The Eustachian tubes open into the nasopharynx and connect it to the middle ear. If an infection travels from the nasopharynx to the middle ear, otitis media occurs.

Features of the larynxbaby

The larynx in children is funnel-shaped and is an extension of the pharynx. In children it is located higher than in adults and has a narrowing in the area cricoid cartilage, where the subglottic space is located. The glottis is formed by the vocal cords. They are short and thin, this is responsible for the child’s high, sonorous voice. The diameter of the larynx in a newborn in the area of ​​the subglottic space is 4 mm, at 5-7 years old - 6-7 mm, by 14 years old - 1 cm. Features of the larynx in children are: narrow clearance, many nerve receptors, easily occurring swelling of the submucosal layer, which can lead to severe breathing problems.

The thyroid cartilages form a more acute angle in boys over 3 years of age; from the age of 10, a typical male larynx is formed.

Features of the tracheababy

The trachea is a continuation of the larynx. It is wide and short, the tracheal frame consists of 14-16 cartilaginous rings, which are connected by a fibrous membrane instead of an elastic end plate in adults. The presence of a large number of muscle fibers in the membrane contributes to changes in its lumen.

Anatomically, the trachea of ​​a newborn is at level IV cervical vertebra, and in an adult - at the level of the VI-VII cervical vertebra. In children, it gradually descends, as does its bifurcation, which is located in a newborn at the level of the third thoracic vertebra, in children 12 years old - at the level of the V-VI thoracic vertebra.

In progress physiological breathing the lumen of the trachea changes. During coughing, it decreases by 1/3 of its transverse and longitudinal dimensions. The mucous membrane of the trachea is rich in glands that secrete a secretion that covers the surface of the trachea with a layer 5 microns thick.

The ciliated epithelium promotes the movement of mucus at a speed of 10-15 mm/min from the inside to the outside.

Features of the trachea in children contribute to the development of its inflammation - tracheitis, which is accompanied by a rough, low-timbre cough, reminiscent of a cough “like in a barrel”.

Features of the child's bronchial tree

The bronchi in children are formed at birth. Their mucous membrane is richly supplied with blood vessels and is covered with a layer of mucus, which moves at a speed of 0.25-1 cm/min. A feature of the bronchi in children is that elastic and muscle fibers are poorly developed.

The bronchial tree branches to the bronchi of the 21st order. With age, the number of branches and their distribution remain constant. The size of the bronchi changes rapidly in the first year of life and during puberty. They are based on cartilaginous semirings in early childhood. Bronchial cartilage is very elastic, pliable, soft and easily displaced. The right bronchus is wider than the left and is a continuation of the trachea, so foreign bodies are more often found in it.

After the birth of a child, a columnar epithelium with a ciliated apparatus is formed in the bronchi. With hyperemia of the bronchi and their swelling, their lumen sharply decreases (up to its complete closure).

Underdevelopment of the respiratory muscles contributes to a weak cough impulse in small child, which can lead to blockage of small bronchi with mucus, and this, in turn, leads to infection of the lung tissue and disruption of the cleansing drainage function of the bronchi.

With age, as the bronchi grow, wide lumens of the bronchi appear, and the bronchial glands produce less viscous secretions. acute diseases bronchopulmonary system compared to younger children.

Features of the lungsin children

The lungs in children, as in adults, are divided into lobes, and lobes into segments. The lungs have a lobular structure, the segments in the lungs are separated from each other by narrow grooves and partitions of connective tissue. The main structural unit is the alveoli. Their number in a newborn is 3 times less than in an adult. Alveoli begin to develop from 4-6 weeks of age, their formation occurs up to 8 years. After 8 years, children’s lungs increase due to their linear size, and at the same time, the respiratory surface of the lungs increases.

The following periods can be distinguished in the development of the lungs:

1) from birth to 2 years, when intensive growth of the alveoli occurs;

2) from 2 to 5 years, when elastic tissue intensively develops, bronchi with peribronchial inclusions of lung tissue are formed;

3) from 5 to 7 years, the functional abilities of the lungs are finally formed;

4) from 7 to 12 years, when a further increase in lung mass occurs due to the maturation of lung tissue.

Anatomically, the right lung consists of three lobes (upper, middle and lower). By 2 years, the sizes of the individual lobes correspond to each other, like in an adult.

In addition to the lobar division, segmental division is distinguished in the lungs: in the right lung there are 10 segments, in the left - 9.

The main function of the lungs is breathing. It is believed that 10,000 liters of air pass through the lungs daily. Oxygen absorbed from the inhaled air ensures the functioning of many organs and systems; the lungs take part in all types of metabolism.

The respiratory function of the lungs is carried out with the help of a biologically active substance - surfactant, which also has a bactericidal effect, preventing fluid from entering the pulmonary alveoli.

The lungs remove waste gases from the body.

A feature of the lungs in children is the immaturity of the alveoli; they have a small volume. This is compensated by increased breathing: than younger child, the more shallow his breathing. The respiratory rate in a newborn is 60, in an adolescent it is already 16-18 breathing movements in 1 minute. Lung development is completed by age 20.

The most various diseases may interfere with the vital respiratory function of children. Due to the characteristics of aeration, drainage function and evacuation of secretions from the lungs, the inflammatory process is often localized in the lower lobe. This occurs when children are lying down infancy due to insufficient drainage function. Paravisceral pneumonia most often occurs in the second segment of the upper lobe, as well as in the basal-posterior segment of the lower lobe. The middle lobe of the right lung may often be affected.

Greatest diagnostic value have the following studies: x-ray, bronchology, determination of blood gas composition, blood pH, study of external respiration function, study of bronchial secretions, computed tomography.

By the frequency of breathing and its relationship with the pulse, the presence or absence of respiratory failure(see table 14).

The respiratory organs are in close connection with the circulatory system. They enrich the blood with oxygen, necessary for oxidative processes occurring in all tissues.

Tissue respiration, that is, the use of oxygen directly from the blood, occurs in the prenatal period, along with the development of the fetus, and external breathing, i.e., the exchange of gases in the lungs, begins in the newborn after cutting the umbilical cord.

What is the mechanism of breathing?

With each inhalation, the chest expands. The air pressure in it decreases and, according to the laws of physics, outside air enters the lungs, filling the rarefied space formed here. When you exhale, the chest contracts and air from the lungs rushes out. The chest is brought into motion thanks to the work of the intercostal muscles and the diaphragm (the abdominal barrier).

The act of breathing is controlled by the breathing center. It is located in medulla oblongata. Carbon dioxide accumulating in the blood serves as an irritant to the respiratory center. Inhalation is replaced by exhalation reflexively (unconsciously). But the higher department, the cortex, also takes part in the regulation of breathing. cerebral hemispheres; With an effort of will, you can hold your breath for a short time or make it more often, deeper.

The so-called airways, i.e., nasal cavities, larynx, bronchi, are relatively narrow in a child. The mucous membrane is tender. It has a dense network of tiny vessels (capillaries), is easily inflamed and swells; this leads to the switching off of breathing through the nose.

Meanwhile, nasal breathing very important. It warms, moisturizes and cleanses (which helps preserve tooth enamel) the air passing into the lungs, irritates the nerve endings that affect the stretching of the bronchi and pulmonary vesicles.

Increased metabolism and, in connection with this, an increased need for oxygen and active motor activity lead to an increase in the vital capacity of the lungs (the amount of air that can be exhaled after a maximum inhalation).

In a three-year-old child, the vital capacity of the lungs is close to 500 cubic cm; by the age of 7 it doubles, by 10 it triples, and by 13 it quadruples.

Due to the fact that the volume of air in the airways of children is less than that of adults, and the need for oxidative processes is high, the child has to breathe more often.

The number of respiratory movements per minute in a newborn is 45-40, in a one-year-old - 30, in a six-year-old - 20, in a ten-year-old - 18. In physically trained people, the respiratory rate at rest is lower. This is due to the fact that they breathe more deeply. and the oxygen utilization rate is higher.

Hygiene and training of the respiratory tract

It is necessary to pay serious attention to the respiratory hygiene of children, in particular to hardening and accustoming them to nasal breathing.

Respiratory organs in a child differ significantly from the respiratory system of an adult. By the time of birth, the child’s respiratory system has not yet reached full development, therefore, in the absence of proper care, children experience an increased incidence of respiratory diseases. Largest number These diseases occur between the ages of 6 months and 2 years.

Studying the anatomical and physiological characteristics of the respiratory organs and conducting a wide range of preventive measures Taking these features into account, they can contribute to a significant reduction in respiratory diseases, which are still one of the main causes of child mortality.

Nose the child is relatively small, the nasal passages are narrow. The mucous membrane lining them is tender, easily vulnerable, rich in blood and lymphatic vessels; this creates conditions for the development of an inflammatory reaction and swelling of the mucous membrane during infection of the upper respiratory tract.

Normally, a child breathes through his nose; he cannot breathe through his mouth.

With age, as the upper jaw develops and the facial bones grow, the length and width of the tracts increase.

The Eustachian tube, which connects the nasopharynx with the tympanic cavity of the ear, is relatively short and wide; it has a more horizontal direction than that of an adult. All this contributes to the introduction of infection from the nasopharynx into the middle ear cavity, which explains the frequency of its involvement in upper respiratory tract disease in a child.

The frontal sinus and maxillary cavities develop only by 2 years, but they reach their final development much later.

Larynx in young children it has a funnel shape. Its lumen is narrow, the cartilage is pliable, the mucous membrane is very delicate, rich in blood vessels. The glottis is narrow and short. These features explain the frequency and ease of narrowing of the glottis (stenosis), even with relatively moderate inflammation mucous membrane of the larynx, which leads to difficulty breathing.

Trachea and bronchi also have a narrower clearance; their mucous membrane is rich in blood vessels; when inflamed, it easily swells, which causes a narrowing of the lumen of the trachea and bronchi.

Lungs, infant differ from the lungs of an adult in the weak development of elastic tissue, greater blood supply and less airiness. Poor development of elastic lung tissue and insufficient excursion of the chest explains the frequency of atelectasis (collapse of lung tissue) in infants, especially in the lower posterior sections of the lungs, since these sections are poorly ventilated.

Lung growth and development occurs over a fairly long period of time. Lung growth is especially vigorous in the first 3 months of life. As the lungs develop, their structure changes: connective tissue layers are replaced by elastic tissue, the number of alveoli increases, which significantly increases the vital capacity of the lungs.

Thoracic cavity the child's is relatively small. The respiratory excursion of the lungs is limited not only due to the low mobility of the chest, but also due to its small size pleural cavity, which in a young child is very narrow, almost slit-like. Thus, the lungs almost completely fill the chest.

The mobility of the chest is also limited due to weakness of the respiratory muscles. The lungs expand mainly towards the pliable diaphragm, therefore, before walking, the type of breathing in children is diaphragmatic. With age, the respiratory excursion of the chest increases and a thoracic or abdominal type of breathing appears.

Age-related anatomical and morphological features of the chest determine some functional features of the breathing of children at different age periods.

The oxygen requirement of a child during a period of intensive growth is very high due to increased metabolism. Since breathing in infants and young children is superficial, the high oxygen demand is covered by the respiratory rate.

Within a few hours after the newborn’s first breath, breathing becomes correct and fairly uniform; sometimes it is established only after a few days.

Number of respirations in a newborn up to 40-60 per minute, in a child of 6 months - 35-40, in 12 months - 30-35, in 5-6 years - 25, at the age of 15 years - 20, in an adult - 16.

The number of respirations must be counted calm state child, watching the breathing movements of the chest or placing a hand on the stomach.

Vital capacity of the lungs the child's is relatively large. In school-age children, it is determined by spirometry. The child is asked to do deep breath and pa special device- spirometer - measure the maximum amount of air exhaled after this ( table 6.) (according to N.A. Shalkova).

Table 6. Vital capacity of the lungs in children (in cm3)

With age, the vital capacity of the lungs increases. It also increases as a result of training, with physical work and playing sports.

Breathing is regulated by the respiratory center, which receives reflex irritations from the pulmonary branches vagus nerve. The excitability of the respiratory center is regulated by the cerebral cortex and the degree of blood saturation with carbon dioxide. With age, cortical regulation of breathing improves.

As the lungs and chest develop and the respiratory muscles strengthen, breathing becomes deeper and less frequent. By the age of 7-12, the breathing pattern and shape of the chest are almost no different from those of an adult.

Proper development of the chest, lungs and respiratory muscles a child depends on the conditions in which he grows up. If a child lives in a stuffy room where people smoke, cook food, wash and dry clothes, or is in a stuffy, unventilated room, then conditions are created that violate normal development his chest and lungs.

To strengthen the child’s health and good development of the respiratory system, prevent respiratory diseases, it is necessary for the child to be on fresh air winter and summer. Outdoor games, sports and physical exercise are especially useful.

Exclusively important role in strengthening the health of children, it is necessary to take them out of the city, where it is possible to organize the children’s stay in the air for the whole day.

The rooms in which children are located must be thoroughly ventilated. In winter, you should open the windows or transoms several times a day according to the established procedure. In a room with central heating, if there are transoms, ventilation can be carried out very often without cooling it. During the warm season, windows should be open around the clock.

There are several stages in the development of the respiratory system:

Stage 1 – up to 16 weeks intrauterine development the formation of bronchial glands occurs.

From the 16th week - the recanalization stage - cellular elements begin to produce mucus and fluid and, as a result, the cells are completely displaced, the bronchi acquire lumen, and the lungs become hollow.

Stage 3 - alveolar - begins from 22 - 24 weeks and continues until the birth of the child. During this period, the formation of the acini, alveoli, and the synthesis of surfactant occurs.

By the time of birth, there are about 70 million alveoli in the fetal lungs. From 22-24 weeks, differentiation of alveolocytes begins - the cells lining inner surface alveoli

There are 2 types of alveolocytes: type 1 (95%), type 2 – 5%.

Surfactant is a substance that prevents the alveoli from collapsing due to changes in surface tension.

It lines the alveoli from the inside thin layer, during inspiration, the volume of the alveoli increases, surface tension increases, which leads to respiratory resistance.

During exhalation, the volume of the alveoli decreases (more than 20-50 times), surfactant prevents their collapse. Since 2 enzymes are involved in the production of surfactant, they are activated by different dates gestation (at the latest from 35-36 weeks), it is clear that the shorter the child’s gestational age, the more pronounced the surfactant deficiency and the higher the likelihood of developing bronchopulmonary pathology.

Surfactant deficiency also develops in mothers with preeclampsia, during complicated pregnancy, caesarean section. The immaturity of the surfactant system is manifested by the development of respiratory distress syndrome.

Surfactant deficiency leads to collapse of the alveoli and the formation of atelectasis, as a result of which the function of gas exchange is disrupted, the pressure in the pulmonary circulation increases, which leads to the persistence of fetal circulation and the functioning of the patent ductus arteriosus and oval window.

As a result, hypoxia and acidosis develop, vascular permeability increases and the liquid part of the blood with proteins sweats into the alveoli. Proteins are deposited on the wall of the alveoli in the form of half rings - hyaline membranes. This leads to impaired diffusion of gases and the development of severe respiratory failure, which is manifested by shortness of breath, cyanosis, tachycardia, and the participation of auxiliary muscles in the act of breathing.

The clinical picture develops within 3 hours from the moment of birth and changes increase within 2-3 days.

AFO of the respiratory organs

By the time a child is born, the respiratory system reaches morphological maturity and can perform the function of breathing.
In a newborn, the respiratory tract is filled with a liquid that has low viscosity and a small amount of protein, which ensures its rapid absorption after the birth of the child through the lymphatic and blood vessels. In the early neonatal period, the child adapts to extrauterine existence.
After 1 inhalation, a short inspiratory pause occurs, lasting 1-2 seconds, after which exhalation occurs, accompanied by a loud cry of the child. In this case, the first respiratory movement in a newborn is carried out as a gasping (inspiratory “flash”) - this is a deep breath with difficult exhalation. Such breathing persists in healthy full-term infants until the first 3 hours of life. In a healthy newborn baby, with the first exhalation, most of the alveoli expand, and at the same time, vasodilation occurs. Complete expansion of the alveoli occurs within the first 2-4 days after birth.
The mechanism of the first breath. The main trigger point is hypoxia, which occurs as a result of clamping of the umbilical cord. After ligation of the umbilical cord, oxygen tension in the blood drops, carbon dioxide pressure increases and pH decreases. In addition, for a newborn child big influence renders temperature environment, which is lower than in the womb. Contraction of the diaphragm creates negative pressure in the chest cavity, which allows air to enter the airways more easily.

A newborn child has well-expressed defensive reflexes– cough and sneezing. Already in the first days after the birth of a child, the Hering-Breuer reflex functions, leading to threshold stretching pulmonary alveoli to the transition of inhalation to exhalation. In an adult, this reflex occurs only with very strong stretching of the lungs.

Anatomically, the upper, middle and lower respiratory tract are distinguished. The nose is relatively small at the time of birth, the nasal passages are narrow, the lower nasal passage and the nasal concha, which are formed by the age of 4, are absent. Submucosal tissue is poorly developed (matures by 8-9 years), cavernous or cavernous tissue is underdeveloped up to 2 years (as a result, young children do not experience nosebleeds). The nasal mucosa is delicate, relatively dry, and rich in blood vessels. Due to the narrowness of the nasal passages and the abundant blood supply to their mucous membrane, even minor inflammation causes difficulty breathing through the nose in young children. Breathing through the mouth is impossible in children in the first six months of life, since the large tongue pushes the epiglottis backward. The exit from the nose - the choanae - is especially narrow in young children, which is often the cause of long-term disruption of nasal breathing in them.

The paranasal sinuses in young children are very poorly developed or completely absent. As they increase in size facial bones (upper jaw) and teeth erupt, the length and width of the nasal passages and the volume of the paranasal sinuses increase. These features explain the rarity of diseases such as sinusitis, frontal sinusitis, ethmoiditis in early childhood. A wide nasolacrimal duct with underdeveloped valves contributes to the transfer of inflammation from the nose to the mucous membrane of the eyes.

The pharynx is narrow and small. The lymphopharyngeal ring (Waldeyer-Pirogov) is poorly developed. It consists of 6 tonsils:

• 2 palatines (between the anterior and posterior palatines)

  2 tubes (near the Eustachian tubes)

  1 throat (in the upper part of the nasopharynx)

  1 lingual (in the area of ​​the root of the tongue).

The palatine tonsils are not visible in newborns; by the end of the 1st year of life they begin to protrude from behind the palatine arches. By the age of 4-10 years, the tonsils are well developed and their hypertrophy can easily occur. IN puberty tonsils begin to undergo reverse development. The Eustachian tubes in young children are wide, short, straight, located horizontally and at horizontal position baby pathological process from the nasopharynx easily spreads to the middle ear, causing the development of otitis media. With age they become narrow, long, and tortuous.

The larynx has a funnel shape. The glottis is narrow and located high (at the level of the 4th cervical vertebra, and in adults - at the level of the 7th cervical vertebra). Elastic tissue is poorly developed. The larynx is relatively longer and narrower than in adults; its cartilages are very pliable. With age, the larynx acquires a cylindrical shape, becomes wide and descends 1-2 vertebrae lower. The false vocal cords and mucous membrane are delicate, rich in blood and lymphatic vessels, elastic tissue is poorly developed. The glottis in children is narrow. Young children's vocal cords are shorter than those of older children, which is why they have a high-pitched voice. From the age of 12, boys' vocal cords become longer than girls'.

The bifurcation of the trachea lies higher than in an adult. The cartilaginous frame of the trachea is soft and easily narrows the lumen. Elastic tissue is poorly developed, the mucous membrane of the trachea is tender and richly supplied with blood vessels. The growth of the trachea occurs in parallel with the growth of the body, most intensively in the 1st year of life and during puberty.

The bronchi are richly supplied with blood, muscle and elastic fibers in young children are underdeveloped, and the lumen of the bronchi is narrow. Their mucous membrane is richly vascularized.
The right bronchus is like a continuation of the trachea; it is shorter and wider than the left. This explains the frequent occurrence foreign body into the right main bronchus.
The bronchial tree is poorly developed.
There are bronchi of the 1st order - main, 2nd order - lobar (3 on the right, 2 on the left), 3rd order - segmental (10 on the right, 9 on the left). The bronchi are narrow, their cartilage is soft. Muscle and elastic fibers in children of the 1st year of life are not yet sufficiently developed, the blood supply is good. The mucous membrane of the bronchi is lined with ciliated epithelium, which provides mucociliary clearance, which plays a major role in protecting the lungs from various pathogens from the upper respiratory tract and has immune function(secretory immunoglobulin A). The tenderness of the bronchial mucosa and the narrowness of their lumen explain the frequent occurrence of bronchiolitis with the syndrome of complete or partial obstruction and pulmonary atelectasis in young children.

Lung tissue is less airy, elastic tissue is underdeveloped. In the right lung there are 3 lobes, in the left 2. Then the lobar bronchi are divided into segmental ones. A segment is an independently functioning unit of the lung, with its apex directed towards the root of the lung, and has an independent artery and nerve. Each segment has independent ventilation, a terminal artery and intersegmental septa made of elastic connective tissue. The segmental structure of the lungs is already well expressed in newborns. There are 10 segments in the right lung, and 9 in the left lung. The upper left and right lobes are divided into three segments - 1st, 2nd and 3rd, middle right lobe- into two segments - 4th and 5th. In the left lung, the middle lobe corresponds to the lingular lobe, which also consists of two segments - the 4th and 5th. The lower lobe of the right lung is divided into five segments - 6, 7, 8, 9 and 10th, the left lung - into four segments - 6, 7, 8 and 9th. The acini are underdeveloped, the alveoli begin to form from 4 to 6 weeks of life and their number quickly increases within 1 year, increasing up to 8 years.

The oxygen requirement in children is much higher than in adults. Thus, in children of the 1st year of life, the need for oxygen per 1 kg of body weight is about 8 ml/min, in adults - 4.5 ml/min. The shallow nature of breathing in children is compensated by a high breathing frequency, the participation of most of the lungs in breathing

In the fetus and newborn, hemoglobin F predominates, which has an increased affinity for oxygen, and therefore the dissociation curve of oxyhemoglobin is shifted to the left and up. Meanwhile, in a newborn, like in a fetus, red blood cells contain extremely little 2,3-diphosphoglycerate (2,3-DPG), which also causes less saturation of hemoglobin with oxygen than in an adult. At the same time, in the fetus and newborn, oxygen is more easily transferred to the tissues.

In healthy children, depending on age, different breathing patterns are determined:

a) vesicular - exhalation is one third of inhalation.

b) puerile breathing - enhanced vesicular

V) hard breathing- exhalation is more than half of inhalation or equal to it.

G) bronchial breathing- exhalation is longer than inhalation.

It is also necessary to note the sonority of breathing (normal, increased, weakened). In children of the first 6 months. breathing is weakened. After 6 months up to 6 years of age, breathing is puerile, and from 6 years of age - vesicular or intensely vesicular (one third of inhalation and two thirds of exhalation are heard), it is heard evenly over the entire surface.

Respiratory rate (RR)

	Frequency per minute
Premature
Newborn

Stange test - holding your breath while inhaling (6-16 years old - from 16 to 35 seconds).

Gench's test - holding your breath while exhaling (N - 21-39 seconds).