Functional features of the respiratory system in children. The breath of the baby, as it should be

Respiratory organs in a child significantly different from the respiratory organs 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 have an increased incidence of respiratory diseases. The greatest number of these diseases falls on the age from 6 months to 2 years.

The study of the anatomical and physiological features of the respiratory organs and the implementation of a wide range of preventive measures, taking into account these features, can contribute to a significant reduction in respiratory diseases, which are still one of the main causes of infant 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 the nose, he does not know how to breathe through his mouth.

With age, as the upper jaw develops and the facial bones grow, the length and width of the action moves 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 cavity of the middle ear, which explains the frequency of its defeat in case of 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-shaped form. Its lumen is narrow, the cartilages are supple, the mucous membrane is very tender, 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 mild inflammation of the mucous membrane of the larynx, which leads to difficulty breathing.

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

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

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

chest cavity the child is relatively small. Respiratory excursion of the lungs is limited not only because of the low mobility of the chest, but also because of the small size of the 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 the weakness of the respiratory muscles. The lungs expand mainly towards the supple 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 of the functional features of breathing in children in different age periods.

The need for oxygen in 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 first breath of a newborn, breathing becomes correct and fairly uniform; sometimes it takes only a few days.

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

Counting the number of breaths should be done in a calm state of the child, following the respiratory movements of the chest or placing a hand on the stomach.

Vital capacity of the lungs the child is relatively large. In school-age children, it is determined by spirometry. The child is offered to take a deep breath and on a special device - a spirometer - they measure the maximum amount of air exhaled after this ( tab. 6.) (according to N. A. Shalkov).

Table 6. Vital lung capacity in children (in cm3)

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

Respiration is regulated by the respiratory center, which receives reflex stimuli from the pulmonary branches of the vagus nerve. The excitability of the respiratory center is regulated by the cerebral cortex and the degree of saturation of the blood with carbon dioxide. With age, the cortical regulation of respiration 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 nature of breathing and the shape of the chest almost do not differ from those of an adult.

The correct development of the chest, lungs and respiratory muscles of the child depends on the conditions in which he grows. If a child lives in a stuffy room where they smoke, cook food, wash and dry clothes, or stay in a stuffy, unventilated room, then conditions are created that disrupt the normal development of his chest and lungs.

To improve the health of the child and the good development of the respiratory system, to prevent respiratory diseases, it is necessary that the child spends a long time in the fresh air in winter and summer. Outdoor games, sports and physical exercises are especially useful.

An exceptionally important role in strengthening the health of children is played by taking them out of the city, where it is possible to organize the stay of children in the open air for a whole day.

Rooms where children are present must be thoroughly ventilated. In winter, windows or transoms should be opened several times a day in the prescribed manner. In a room with central heating, in the presence of transoms, ventilation can be carried out very often without cooling it. In the warm season, windows should be open around the clock.

The beginning of the formation of the tracheopulmonary system begins at the 3-4th week of embryonic development. Already by the 5th-6th week of embryonic development, branching of the second order appears and the formation of three lobes of the right lung and two lobes of the left lung is predetermined. During this period, the trunk of the pulmonary artery is formed, which grows into the lungs along the course of the primary bronchi.

In the embryo at the 6th-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, there are already areas of lung tissue. They, together with segmental bronchi, arteries and veins, form the embryonic lung segments.

Between the 4th and 6th months there is a rapid growth of the pulmonary vasculature.

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 in the airways, especially the respiratory section of the lungs, occur. The formation of the respiratory surface in individual sections of the lungs occurs unevenly. The condition and readiness of the surfactant film lining the lung surface is of great importance for the expansion of the respiratory apparatus of the lungs. Violation of the surface tension of the surfactant system leads to serious illnesses in a young child.

In the first months of life, the child retains the ratio of the length and width of the airways, as in the 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 child is thicker, looser, contains villi, outgrowths, especially in the interlobar grooves. Pathological foci appear in these areas. The lungs for the birth of a child are prepared to perform the function of respiration, but individual components are at the stage of development, 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. a period of intensive growth of the lung lobes (from 3 months to 3 years).
2. final differentiation of the entire 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 small bronchi grow intensively, 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 up to 8 months, the diameter of the alveoli is 0.06 mm, at 2 years - 0.12 mm, at 6 years - 0.2 mm, at 12 years - 0.25 mm.

In the first years of life, growth and differentiation of elements of the lung tissue and blood vessels occur. The ratio of share volumes in individual segments is leveled out. Already at the age of 6-7 years, the lungs are a formed organ and are indistinguishable in comparison with the lungs of adults.

Features of the child's respiratory tract

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

The main function of respiration is to conduct air into the lungs, clean it from dust particles, protect the lungs from the harmful effects of bacteria, viruses, and foreign particles. In addition, the respiratory tract warms and humidifies 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 atmospheric air and release gases into the atmosphere, primarily carbon dioxide.

Breathing mechanism. When inhaling, the diaphragm and chest muscles contract. Exhalation at an older age occurs passively under the influence of the elastic traction of the lungs. With obstruction of the bronchi, emphysema, as well as in newborns, active inspiration takes place.

Normally, respiration is established with such a frequency at which the volume of respiration is performed due to the minimum energy expenditure of the respiratory muscles. In newborns, 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 to form 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 property of easily binding oxygen and difficult to give it to the tissues. This helps the child in the presence of oxygen starvation.

The transport of carbon dioxide occurs in a dissolved form, the saturation of the blood with oxygen affects the content of carbon dioxide.

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

During breathing, its autoregulation is noted. When the lung is stretched during inhalation, the inspiratory center is inhibited, and during exhalation, exhalation is stimulated. Deep breathing or forced inflation of the lungs leads to reflex expansion of the bronchi and increases the tone of the respiratory muscles. With the collapse and compression of the lungs, the bronchi narrow.

The respiratory center is located in the medulla oblongata, from where commands are sent to the respiratory muscles. The bronchi lengthen during inhalation, and shorten and narrow during exhalation.

The relationship between the functions of respiration and blood circulation is manifested from the moment the lungs expand at the first breath of a newborn, when both the alveoli and blood vessels expand.

Respiratory problems in children can lead to impaired respiratory function and respiratory failure.

Features of the structure of the child's nose

In young children, the nasal passages are short, the nose is flattened due to an underdeveloped facial skeleton. The nasal passages are narrower, the shells are thickened. The nasal passages are finally formed only by 4 years. The nasal cavity is relatively small. The mucous membrane is very loose, well supplied with blood vessels. The inflammatory process leads to the development of edema and reduction due to this lumen of the nasal passages. Often there is stagnation of mucus in the nasal passages. It can dry out, forming crusts.

When closing the nasal passages, shortness of breath may occur, the child during this period cannot suckle the breast, worries, throws the breast, remains hungry. Children, due to the difficulty of nasal breathing, begin to breathe through the mouth, their heating of the incoming air is disturbed and their tendency to catarrhal diseases increases.

If nasal breathing is disturbed, there is a lack of odor discrimination. This leads to a violation of appetite, as well as a violation of the idea of ​​​​the external environment. Breathing through the nose is physiological, breathing through the mouth is a symptom of a disease of the nose.

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

Features of the lacrimal canal. The lacrimal canal is shorter than in adults, its valves are not sufficiently developed, and the outlet is close to the corner of the eyelids. In connection with these features, the infection quickly gets from the nose into the conjunctival sac.

Features of the pharynxchild

The pharynx in young children is relatively wide, the palatine tonsils are poorly developed, which explains the rare diseases of angina in the first year of life. Completely tonsils develop by 4-5 years. By the end of the first year of life, the tonsil tissue becomes hyperplastic. But its barrier function at this age is very low. The overgrown tonsil tissue can be susceptible to infection, so diseases such as tonsillitis, adenoiditis occur.

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

Features of the larynxchild

The larynx in children is funnel-shaped and is a continuation of the pharynx. In children, it is located higher than in adults, it has a narrowing in the area of ​​the cricoid cartilage, where the subglottic space is located. The glottis is formed by the vocal cords. They are short and thin, this is due to the high sonorous voice of the child. The diameter of the larynx in a newborn in the region of the subglottic space is 4 mm, at 5–7 years old it is 6–7 mm, by the age of 14 it is 1 cm. layer, which can lead to severe respiratory problems.

In boys older than 3 years, the thyroid cartilages form a sharper angle; from the age of 10, a typical male larynx is formed.

Features of the tracheachild

The trachea is a continuation of the larynx. It is wide and short, the framework of the trachea 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 a change in its lumen.

Anatomically, the trachea of ​​a newborn is at the level of the IV cervical vertebra, and in an adult it is 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 III thoracic vertebra, in children of 12 years old - at the level of the V-VI thoracic vertebra.

In the process of physiological respiration, 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 secret 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 in the direction 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-pitched cough, reminiscent of a cough "like a barrel".

Features of the bronchial tree of a child

The bronchi in children are formed by birth. Their mucous membrane is richly supplied with blood vessels, 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 the 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 dimensions of the bronchi change intensively 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 cylindrical epithelium with a ciliated apparatus is formed in the bronchi. With hyperemia of the bronchi and their edema, their lumen sharply decreases (up to its complete closure).

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

With age, as the bronchi grow, the appearance of wide lumen of the bronchi, the production of a less viscous secret by the bronchial glands, acute diseases of the bronchopulmonary system are less common compared to children of an earlier age.

Lung Featuresin children

The lungs in children, as in adults, are divided into lobes, lobes into segments. The lungs have a lobed structure, the segments in the lungs are separated from each other by narrow grooves and partitions made 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, the lungs in children increase due to the linear size, in parallel, the respiratory surface of the lungs increases.

In the development of the lungs, the following periods can be distinguished:

1) from birth to 2 years, when there is an intensive growth of the alveoli;

2) from 2 to 5 years, when elastic tissue develops intensively, bronchi with perebronchial 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 there is a further increase in lung mass due to the maturation of lung tissue.

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

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

The main function of the lungs is breathing. It is believed that 10,000 liters of air pass through the lungs every day. 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 - a surfactant, which also has a bactericidal effect, preventing fluid from entering the pulmonary alveoli.

With the help of the lungs, waste gases are removed 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: the younger the child, the more shallow his breathing. The respiratory rate in a newborn is 60, in a teenager it is already 16-18 respiratory movements per 1 minute. The development of the lungs is completed by the age of 20.

A wide variety of diseases can interfere with the vital function of breathing in 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 in the supine state in infants due to insufficient drainage function. Paravisceral pneumonia 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.

The following studies are of the greatest diagnostic value: x-ray, bronchological, determination of blood gas composition, blood pH, examination of the function of external respiration, examination of bronchial secretions, and computed tomography.

According to the frequency of breathing, its ratio with the pulse, the presence or absence of respiratory failure is judged (see Table 14).

The respiratory system is a collection of organs consisting of the respiratory tract (nose, pharynx, trachea, bronchi), lungs (bronchial tree, acini), as well as muscle groups that contribute to the contraction and relaxation of the chest. Breathing provides the cells of the body with oxygen, which in turn converts it into carbon dioxide. This process occurs in the pulmonary circulation.

The laying and development of the child's respiratory system begins during the 3rd week of a woman's pregnancy. It is formed from three rudiments:

• Splanchnotome.
• Mesenchyme.
• Epithelium of the foregut.

From the visceral and parietal sheets of the splanchnotome, the mesothelium of the pleura develops. It is represented by a single-layer squamous epithelium (polygonal cells), lining the entire surface of the pulmonary system, separating from other organs. The outer surface of the leaf is covered with microcilia that produce a serous fluid. It is necessary for sliding between the two layers of the pleura during inhalation and exhalation.

From the mesenchyme, namely the germ layer of the mesoderm, cartilage, muscle and connective tissue structures, and blood vessels are formed. From the epithelium of the anterior intestine takes the development of the bronchial tree, lungs, alveoli.

In the intrauterine period, the airways and lungs are filled with fluid, which is removed during childbirth with the first breath, and is also absorbed by the lymphatic system and partially into the blood vessels. Breathing is carried out at the expense of maternal blood, enriched with oxygen, through the umbilical cord.

By the eighth month of gestation, pneumocytes produce a surfactant called surfactant. It lines the inner surface of the alveoli, prevents them from falling off and sticking together, and is located at the air-liquid interface. Protects against harmful agents with the help of immunoglobulins and macrophages. Insufficient secretion or absence of surfactant threatens the development of respiratory distress syndrome.

A feature of the respiratory system in children is its imperfection. The formation and differentiation of tissues, cell structures is carried out in the first years of life and up to seven years.

Structure

Over time, the child's organs adapt to the environment in which he will live, the necessary immune, glandular cells are formed. In a newborn, the respiratory tract, unlike an adult organism, has:

• Narrower opening.
• Short stroke length.
• Many vascular vessels in a limited area of ​​the mucosa.
• Delicate, easily traumatized architectonics of the lining membranes.
• Loose structure of lymphoid tissue.

Upper paths

The baby's nose is small, its passages are narrow and short, so the slightest swelling can lead to obstruction, which makes sucking difficult.

The structure of the upper tract in a child:

1. Two nasal sinuses are developed - the upper and middle ones, the lower one will be formed by the age of four. The cartilage framework is soft and pliable. The mucous membrane has an abundance of blood and lymphatic vessels, and therefore minor manipulation can lead to injury. Nosebleeds are rarely noted - this is due to undeveloped cavernous tissue (it will form by the age of 9). All other cases of blood flow from the nose are considered pathological.
2. The maxillary sinuses, the frontal and ethmoid sinuses are not closed, protrude the mucous membrane, are formed by 2 years, cases of inflammatory lesions are rare. Thus, the shell is more adapted to the purification, humidification of the inhaled air. Full development of all sinuses occurs by the age of 15.
3. The nasolacrimal canal is short, exits in the corner of the eye, close to the nose, which ensures a rapid ascending spread of inflammation from the nose to the lacrimal sac and the development of polyetiological conjunctivitis.
4. The pharynx is short and narrow, due to which it is quickly infected through the nose. At the level between the oral cavity and the pharynx, there is a Pirogov-Waldeyer nasopharyngeal annular formation, consisting of seven structures. The concentration of lymphoid tissue protects the entrance to the respiratory and digestive organs from infectious agents, dust, allergens. Features of the structure of the ring: poorly formed tonsils, adenoids, they are loose, pliable to settlement in their crypts of inflammatory agents. There are chronic foci of infection, frequent respiratory diseases, tonsillitis, difficulty in nasal breathing. Such children develop neurological disorders, they usually walk with their mouths open and are less amenable to schooling.
5. The epiglottis is scapular, relatively wide and short. During breathing, it lies on the root of the tongue - opens the entrance to the lower paths, during the period of eating - prevents the foreign body from entering the respiratory passages.

lower paths

The larynx of a newborn is located higher than that of an adult individual, due to the muscular frame it is very mobile. It has the form of a funnel with a diameter of 0.4 cm, the narrowing is directed towards the vocal cords. The cords are short, which explains the high timbre of the voice. With a slight edema, during acute respiratory diseases, symptoms of croup, stenosis occur, which is characterized by heavy, wheezing breathing with the inability to perform a full breath. As a result, hypoxia develops. The laryngeal cartilages are rounded, their sharpening in boys takes place by the age of 10-12 years.

The trachea is already formed by the time of birth, is located at the level of the 4th cervical vertebra, is mobile, in the form of a funnel, then acquires a cylindrical appearance. The lumen is significantly narrowed, in contrast to an adult, there are few glandular areas in it. When coughing, it can be reduced by a third. Given the anatomical features, in inflammatory processes, narrowing and the occurrence of a barking cough, symptoms of hypoxia (cyanosis, shortness of breath) are inevitable. The frame of the trachea consists of cartilaginous semirings, muscle structures, connective tissue membrane. Bifurcation at birth is higher than in older children.

The bronchial tree is a continuation of the bifurcation of the trachea, divided into the right and left bronchus. The right one is wider and shorter, the left one is narrower and longer. The ciliated epithelium is well developed, producing physiological mucus that cleanses the bronchial lumen. Mucus cilia moves outward at a speed of up to 0.9 cm per minute.

A feature of the respiratory organs in children is a weak cough impulse, due to poorly developed torso muscles, incomplete myelin coverage of the nerve fibers of the tenth pair of cranial nerves. As a result, infected sputum does not go away, accumulates in the lumen of the bronchi of different calibers and there is a blockage with a thick secret. In the structure of the bronchus there are cartilage rings, with the exception of the terminal sections, which consist only of smooth muscles. When they are irritated, a sharp narrowing of the course may occur - an asthmatic picture appears.

The lungs are airy tissue, their differentiation continues up to 9 years of age, they consist of:

• Shares (right of three, left of two).
• Segments (right - 10, left - 9).
• Dolek.

The bronchioles end in a sac in the baby. With the growth of the child, the lung tissue grows, the sacs turn into alveolar clusters, and the vital capacity indicators increase. Active development from the 5th week of life. At birth, the weight of the paired organ is 60–70 grams, it is well supplied with blood and vascularized by lymph. Thus, it is full-blooded, and not airy as in older age. The important point is that the lungs are not innervated, inflammatory reactions are painless, and in this case, you can miss a serious illness.

Due to the anatomical and physiological structure, pathological processes develop in the basal regions, cases of atelectasis and emphysema are not uncommon.

Functional features

The first breath is carried out by reducing oxygen in the blood of the fetus and increasing the level of carbon dioxide, after clamping the umbilical cord, as well as changing the conditions of stay - from warm and humid to cold and dry. Signals along the nerve endings enter the central nervous system, and then to the respiratory center.

Features of the function of the respiratory system in children:

• Air conduction.
• Cleansing, warming, moisturizing.
• Oxygenation and removal of carbon dioxide.
• Protective immune function, synthesis of immunoglobulins.
• Metabolism is the synthesis of enzymes.
• Filtration - dust, blood clots.
• lipid and water metabolism.
• shallow breaths.
• Tachypnea.

In the first year of life, respiratory arrhythmia occurs, which is considered the norm, but its persistence and the occurrence of apnea after one year of age is fraught with respiratory arrest and death.

The frequency of respiratory movements directly depends on the age of the baby - the younger, the more often the breath is taken.

NPV norm:

• Newborn 39–60/minute.
• 1-2 years - 29-35 / min.
• 3-4 years - 23-28 / min.
• 5-6 years - 19-25 / min.
• 10 years - 19-21 / min.
• Adult - 16-21 / min.

Taking into account the peculiarities of the respiratory organs in children, the attentiveness and awareness of parents, timely examination, therapy reduces the risk of transition to the chronic stage of the disease and serious complications.

The first breath in newborns appears immediately after birth, often along with the first cry. Sometimes there is some delay in the first breath due to the pathology of childbirth (asphyxia, intracranial birth trauma) or as a result of reduced excitability of the respiratory center due to an adequate supply of oxygen in the blood of the newborn. In the latter case, there is a short-term cessation of breathing - apnea. If physiological breath holding is not delayed, does not lead to asphyxia, then it usually does not have a negative effect on the further development of the child. In the future, more or less rhythmic, but shallow breathing is established.

In some newborns, especially in premature babies, due to shallow breathing and a weak first cry, the lungs do not fully expand, which leads to the formation of atelectasis, more often in the posterior parts of the lungs. Often these atelectasis are the beginning of the development of pneumonia.

The depth of breathing in children in the first months of life is much less than in older children.

Absolute breathing volume(the amount of air inhaled) gradually increases with age.

Due to shallow breathing in newborns, the poverty of the respiratory tract with elastic tissue, there is a violation of the excretory ability of the bronchi, as a result of which secondary atelectasis is often observed. These atelectasis are more often observed in premature babies due to functional insufficiency of the respiratory center and the entire nervous system.

The respiratory rate in newborns, according to various authors, ranges from 40 to 60 per minute; with age, breathing becomes more rare. According to the observations of A.F. Tur, the frequency of inhalation in children of different ages is as follows:

In young children, the ratio of respiratory rate to pulse rate is 1:3.5 or 1:4.

The volume of the respiratory act multiplied by the frequency of respiration per minute is called minute volume of breathing. Its value is different depending on the age of the child: in a newborn it is 600-700 ml per minute, in the first year of life it is about 1700-1800 ml, in adults it is 6000-8000 ml per minute.

Due to the high respiratory rate in young children, the minute volume of breathing (per 1 kg of weight) is greater than in an adult. In children under 3 years old, it is 200 ml, and in an adult - 100 ml.

The study of external respiration is of great importance in determining the degree of respiratory failure. These studies are carried out using various functional tests (Stange, Hench, spirometry, etc.).

In young children, for obvious reasons, external respiration is examined by counting breaths, pneumography, and clinical observations of the rhythm, frequency, and nature of breathing.

The type of breathing in a newborn and infant is diaphragmatic or abdominal, which is explained by the high standing of the diaphragm, the significant size of the abdominal cavity, and the horizontal arrangement of the ribs. From 2-3 years of age, the type of breathing becomes mixed (chest-abdominal breathing) with the predominance of one or another type of breathing.

After 3-5 years, chest breathing gradually begins to predominate, which is associated with the development of the muscles of the shoulder girdle and a more oblique arrangement of the ribs.

Sex differences in the type of breathing are revealed at the age of 7-14 years: in boys, the abdominal type of breathing is gradually established, in girls - the thoracic type of breathing.

To cover all metabolic needs, a child needs more oxygen than an adult, which in children is achieved by rapid breathing. This requires the correct functioning of external respiration, pulmonary and internal, tissue respiration, i.e., so that normal gas exchange occurs between blood and tissues.

External respiration in children is violated due to the poor composition of the external air (for example, with insufficient ventilation of the premises where children are located). The state of the respiratory apparatus also affects the child's breathing: for example, breathing is quickly disturbed even with slight swelling of the alveolar epithelium, therefore, in young children, oxygen deficiency can more easily occur than in older children. It is known that the air exhaled by a child contains less carbon dioxide and more oxygen than the air exhaled by an adult.

The respiratory coefficient (the ratio between the volume of carbon dioxide released and the volume of oxygen absorbed) in a newborn is 0.7, and in an adult - 0.89, which is explained by the significant oxygen consumption of the newborn.

Easily occurring oxygen deficiency - hypoxemia and hypoxia - worsens the child's condition not only with pneumonia, but also with catarrh of the respiratory tract, bronchitis, rhinitis.

Respiration is regulated by the respiratory center, which is constantly influenced by the cerebral cortex. The activity of the respiratory center is characterized by automaticity and rhythm; two departments are distinguished in it - inspiratory and expiratory (N. A. Mislavsky).

Irritations from extero- and interoreceptors along centripetal pathways arrive at the respiratory center, where processes of excitation or inhibition appear. The role of impulses coming from the lungs is very important. The excitation that occurs during inspiration is transmitted through the vagus nerve to the respiratory center, causing its inhibition, as a result of which impulses are not sent to the respiratory muscles, they relax, and the exhalation phase begins. The afferent endings of the vagus nerve in the collapsed lung are not excited, and inhibitory impulses do not enter the respiratory center. The latter is excited again, which causes a new breath, etc.

The function of the respiratory center is influenced by the composition of the alveolar air, the composition of the blood, the content of oxygen, carbon dioxide, and metabolic products in it. The entire mechanism of external respiration is in close connection with the circulatory, digestive, and hematopoietic systems.

It is known that an increased content of carbon dioxide causes a deepening of respiration, and a lack of oxygen - an increase in respiration.

Under the influence of various emotional moments, the depth and frequency of breathing changes. Many works of domestic scientists have established that the regulation of breathing in children is carried out mainly by the neuroreflex way. Thus, the regulatory role of the central nervous system ensures the integrity of the child's body, its connection with the environment, as well as the dependence of respiration on the function of blood circulation, digestion, metabolism, etc.

Features of the respiratory system in young children

The respiratory organs in young children in anatomical and functional terms differ not only from those in adults, but even in older children. This is explained by the fact that in young children the process of anatomical and histological development has not yet been fully completed. This, of course, affects the frequency and nature of respiratory lesions in children of this age.

Nose the child is relatively small, short, the bridge of the nose is poorly developed, the nasal openings and nasal passages are narrow, the lower nasal passage is almost absent and is formed only by 4-5 years. With the growth of facial bones and teething, the width of the nasal passages increases. The choanae are narrow, resembling transverse fissures, and reach full development by the end of early childhood. The mucous membrane of the nose is delicate, lined with cylindrical ciliated epithelium, rich in blood and lymphatic vessels. Its slightest swelling makes breathing and sucking very difficult. Rhinitis in an infant is certainly combined with pharyngitis, the process is sometimes localized in the larynx, trachea and bronchi.

The cavernous tissue of the submucosal layer is very weakly expressed and develops sufficiently only by the age of 8-9, which, apparently, can explain the rather rare nosebleeds in young children.

Adnexal cavities nose in young children are practically absent, since they are very poorly developed (4-5 times less than in children of senior school age). The frontal sinuses and maxillary cavities develop by the age of 2, but they reach their final development much later, and therefore diseases of these sinuses in young children are extremely rare.

Eustachian tube short, wide, its direction is more horizontal than in an adult. This can explain the significant frequency of otitis in young children, especially in the pathological condition of the nasopharynx.

Nasopharynx and pharynx. The pharynx of a young child is short and has a more vertical direction. Both pharyngeal tonsils do not protrude into the pharyngeal cavity.

By the end of the first year, and in children suffering from exudative or lymphatic diathesis, the tonsils become noticeable much earlier even during a routine examination of the pharynx.

tonsils in children at an early age they also have structural features: the vessels and crypts in them are poorly expressed, as a result of which angina is rarely observed.

With age, lymphoid tissue grows and reaches a maximum between 5 and 10 years. However, even in early childhood, quite frequent catarrhal conditions of the nasopharynx with swelling and redness of the tonsils are noted.

With the growth of certain tonsils, various painful conditions are also observed: with an increase and inflammation of the nasopharyngeal tonsil, adenoids develop, nasal breathing is disturbed. The child begins to breathe through the mouth, speech becomes nasal, sometimes hearing goes down.

Larynx occupies the middle part of the neck anterior to the esophagus and in a child has a funnel-shaped shape with a narrow lumen, with supple and delicate cartilage. The most vigorous growth of the larynx is observed in the first year of life and at puberty.

In a child, the larynx is small, up to 3 years it has the same length in boys and girls. False vocal cords and mucous membrane in young children are tender, very rich in blood vessels. True vocal cords are shorter than in older children.

Particularly enhanced growth is observed in the first year of life and in puberty. The mucous membrane of the larynx is covered with a cylindrical ciliated epithelium, and on the true vocal cords the epithelium is multi-layered, flat, without signs of keratinization, in contrast to adults. The mucous membrane is rich in glands of the acinar type.

The indicated anatomical and physiological features of the larynx explain the difficulty in breathing, which is quite often observed even with mild inflammatory processes of the larynx, reaching stenosis of the larynx, known as "false croup".

Trachea. In children of the first six months of life, the trachea has a funnel-shaped shape, a narrow lumen, and is located 2-3 vertebrae higher than in adults.

The mucous membrane of the trachea is tender, rich in blood vessels and relatively dry due to insufficient development of the glands of the mucous membrane. The cartilage of the trachea is soft, easily compressed and can be displaced.

All these anatomical and physiological features of the trachea contribute to the more frequent occurrence of inflammatory processes and the onset of stenotic phenomena.

The trachea is divided into two main bronchi - right and left. The right bronchus is, as it were, a continuation of the trachea, which explains the more frequent ingress of foreign bodies into it. The left bronchus deviates from the trachea at an angle and is longer than the right one.

Bronchi. In newborns and young children, the bronchi are narrow, poor in muscle and elastic fibers, their mucous membrane is rich in blood vessels, due to which inflammatory processes occur more quickly, and the lumen of the bronchi narrows faster than in older children. In the postnatal period, the differentiation of the structures of the walls of the bronchi, most intensely expressed in the system of the muscular type of the bronchi (V.I. Puzik). The age structure of the bronchial tree plays an important role in the pathology of this organ.

The greatest increase in the size of the bronchi (sagittal and frontal) occurs during the first year of life; the left bronchus lags behind the right.

Lungs. The main functional unit of the lungs is the acinus, consisting of a group of alveoli and bronchioles (1st, 2nd and 3rd order), within which the main function of the lungs is carried out - gas exchange.

In young children, the lungs are more full-blooded and less airy. Interstitial, interstitial tissue of the lung is more developed than in older children, more abundantly supplied with blood vessels.

The lungs of a child are looser, richer in lymphatic vessels and smooth muscle fibers. These structural features of the lungs of a child suggest that they have a greater ability to reduce and more rapidly resorb intraalveolar exudate.

The lungs of an infant are poor in elastic tissue, especially in the circumference of the alveoli and in the walls of the capillaries, which can explain their tendency to form atelectasis, the development of emphysema, and a protective compensatory reaction of the lungs to infection in pneumonia.

The weight of the lungs of a newborn child is, according to Gundobin, 1/34 - 1/54 of his body weight; by the age of 12, it increases 10 times compared with the weight of the lungs of newborns. The right lung is usually larger than the left.

Lung growth occurs with the age of the child, mainly due to an increase in the volume of the alveoli (from 0.05 mm in newborns to 0.12 mm by the end of early childhood and 0.17 mm in adolescence).

At the same time, there is an increase in the capacity of the alveoli and an increase in the elastic elements around the alveoli and capillaries, the replacement of the connective tissue layer with elastic tissue.

Pulmonary fissures in young children are mild and represent shallow furrows on the surfaces of the lungs.

Due to the proximity of the root of the lungs, a group of lymph nodes, as it were, protrudes into the main cracks on both sides and is a source of interlobar pleurisy.

The processes of growth and differentiation of the functional elements of the lung - in the lobule, acinus and intralobular bronchi - end by the age of 7 years (A.I. Strukov, V.I. Puzik).

In recent years, an important contribution to pediatrics has been the developed doctrine of segmental structure of the lungs(A. I. Strukov and I. M. Kodolova).

The authors showed that by the time of the birth of a child, all segments and their corresponding bronchi have already been formed, as in adults. However, this similarity is only external, and in the postnatal period, the differentiation of the lung parenchyma and the growth of subsegmental bronchi continue.

Each segment has its own innervation, artery and vein. On the right there are 10 segments: in the upper lobe -3, in the middle - 2, in the lower - 5. On the left there are 9 (rarely 10) segments: in the upper lobe - 3, in the tongue of the middle lobe -2, in the lower - 4 segments. Each segment consists of 2 subsegments and only the VI and X segments consist of 3 subsegments.

Rice. 1. Scheme of the segmental structure of the lungs according to the nomenclature of the International Congress of Otolaryngologists in 1949 in London.

1st segment s. apicale (1); 2nd segment s. posterius (2); 3rd segment s. anterius (3); 4th segment s. Iaterale (4); 5th segment s. mediale(5); 6th segment s. apicale superius (6); 7th segment s. (basale) mediale (not visible in the diagram); 8th segment s. (basale) anterius (8); 9th segment s. (basale) Iaterale (9); 10th segment s. (basale) posterius (10).

Currently, the generally accepted nomenclature for segments and bronchi is the nomenclature adopted in 1945 at the International Congress of Anatomists in Paris and in 1949 at the International Congress of Otolaryngologists in London.

Based on this, simple schemes of the segmental structure of the lungs have been created [F. Kovacs and Z. Zhebek, 1958, Boyden (Boyden, 1945) and others] (Fig. 1).

lung root(hilus). It consists of large bronchi, nerves, blood vessels, a huge number of lymph nodes.

Lymph nodes in the lungs are divided into the following groups (according to A. F. Tour): 1) tracheal; 2) bifurcation; 3) bronchopulmonary; 4) lymph nodes of large vessels. All lymph nodes are connected by lymphatic pathways with the lungs, as well as with mediastinal and supraclavicular lymph nodes.

The root of the right lung is located slightly higher (at the level of V-VI thoracic vertebrae), the left one is lower (at the level of VI-VII vertebrae). As a rule, the root of the left lung as a whole and its individual elements (pulmonary artery, vein, bronchi) are somewhat behind in their development from the corresponding formations on the right side.

Pleura. In newborns and young children, the pleura is thin, easily displaced. The pleural cavity, as in adults, is formed by two sheets of the pleura - visceral and parietal, as well as two visceral sheets in the interlobar spaces. The pleural cavity in children of this age is easily extensible due to the weak attachment of the parietal pleura to the chest. The accumulation of fluid in the pleura resulting from inflammatory processes in the lungs in young children easily causes them to displace the mediastinal organs, since they are surrounded by loose fiber, which often leads to significant circulatory disorders.

Mediastinum. In children, it is relatively larger than in adults, more elastic and supple. The mediastinum is bounded behind by the bodies of the vertebrae, from below by the diaphragm, from the sides by the sheets of the pleura enveloping the lungs, and in front by the handle and body of the sternum. In the upper part of the mediastinum are the thymus, trachea, large bronchi, lymph nodes, nerve trunks (n. recurrens, n. phrenicus), veins, ascending aortic arch. In the lower part of the mediastinum are the heart, blood vessels, nerves. In the posterior mediastinum are n. vagus, n. sympaticus and part of the esophagus.

Rib cage. The structure and shape of the chest in children can vary significantly depending on the age of the child. The chest of a newborn is relatively shorter in the longitudinal direction, its anteroposterior diameter is almost equal to the transverse one. The shape of the chest is conical, or almost cylindrical, the epigastric angle is very obtuse due to the fact that the ribs in young children are located almost horizontally and perpendicular to the spine (Fig. 2).

The chest is constantly in a state of inhalation, which cannot but affect the physiology and pathology of respiration. This also explains the diaphragmatic nature of breathing in young children.

With age, the anterior part of the chest, sternum, trachea descend with the diaphragm down, the ribs take a more inclined position, as a result of which the chest cavity increases and the epigastric angle becomes more acute. The chest gradually moves from the inspiratory position to the expiratory one, which is one of the prerequisites for the development of chest breathing.

Diaphragm. In children, the diaphragm is high. When it is reduced, the dome flattens and thus the vertical size of the chest cavity increases. Therefore, pathological changes in the abdominal cavity (tumors, enlargement of the liver, spleen, intestinal flatulence and other conditions accompanied by difficulty in diaphragm movements) reduce ventilation to a certain extent.

These features of the anatomical structure of the respiratory organs cause changes in the physiology of respiration in young children.

All of these anatomical and physiological features of breathing in children put the child at a disadvantage compared to adults, which to some extent explains the significant frequency respiratory diseases in young children, as well as their more severe course.

Features of the chest predetermine the shallow nature of breathing in infants, its high frequency, arrhythmia, and irregular alternation of pauses between inhalation and exhalation. At the same time, the depth of breathing (absolute capacity), that is, the amount of air that inhales, in a newborn is much less than in the following periods of childhood and in adults. With age, the capacity of the respiratory act increases. The frequency of breathing in a child is the higher, the smaller it is.

In young children, the need for oxygen is large (increased metabolism), because the shallow nature of breathing is compensated by its frequency. A newborn baby is, as if in a state of constant shortness of breath (physiological shortness of breath of the newborn).

Acceleration of breathing in a child often occurs when he screams, cries, with physical exertion, bronchitis, pneumonia. Minute respiratory capacity is the capacity of the respiratory act multiplied by the frequency. It indicates the degree of oxygen saturation of the lungs. Its absolute value in a child is less than in an adult.

Determination of VC is possible in children from 5-6 years old using a spirometer. Determine the maximum amount of air that is exhaled into the spirometer tube after a maximum breath. With age, VC increases, it also grows as a result of training.

Relative minute respiratory capacity (per 1 kg of body weight) as a result of accelerated breathing in children is much greater than in adults; from birth to 3 years - 200 ml, at 11 years old - 180 ml, in an adult - 100 ml.

The type of breathing in a newborn and a child in the first year of life is diaphragmatic, or abdominal, from 2 years of age breathing is mixed - diaphragmatic-thoracic, and from 8-10 years old in boys it is abdominal, in girls it is chest. The rhythm of breathing in young children is unstable, the pauses between inhalation and exhalation are uneven. This is due to the incomplete development of the respiratory center and increased excitability of the vagal receptors. Respiration is regulated by the respiratory center, which receives reflex irritations from the branches of the vagus nerve.

Gas exchange in the lungs of an infant is more vigorous than in older children and adults. It consists of three phases: 1) external respiration - exchange through the alveoli of the lungs between atmospheric air (air of the external environment) and pulmonary air; 2) pulmonary respiration - exchange between the air of the lungs and blood (due to the diffusion of gases); 3) tissue (internal) respiration - gas exchange between blood and tissues.

The correct development of the chest, lungs, respiratory muscles of the child depends on the conditions in which he grows. To strengthen it and the normal development of the respiratory system, to prevent diseases of the respiratory system, it is necessary that the child stays in the fresh air for a long time in winter and summer. Especially useful outdoor games, sports, physical exercises, outdoors, regular ventilation of rooms where children are.

You should diligently ventilate the room during cleaning, explain to parents the importance of this event.