Anatomical and physiological features of the respiratory system in children. Respiratory diseases in children

The respiratory organs in children not only have an absolutely smaller size, but, in addition, they also differ in some incomplete anatomical and histological structure. The child’s nose is relatively small, its cavities are underdeveloped, and the nasal passages are narrow; The lower nasal passage in the first months of life is completely absent or rudimentarily developed. The mucous membrane is tender, rich in blood vessels, the submucosa in the first years of life is poor in cavernous tissue; at 8-9 years old, the cavernous tissue is already quite developed, and there is especially a lot of it during puberty.

Paranasal cavities in children early age very poorly developed or even completely absent. Frontal sinus appears only in the 2nd year of life, by 6 years it reaches the size of a pea and is finally formed only by 15 years. The maxillary cavity, although already present in newborns, is very small and only from 2 years of age begins to noticeably increase in volume; approximately the same must be said about sinus ethmoidalis. Sinus sphenoidalis in young children is very small; up to 3 years of age, its contents are easily emptied into the nasal cavity; from the age of 6 years, this cavity begins to rapidly increase. Due to the poor development of the paranasal cavities in young children, inflammatory processes from the nasal mucosa very rarely spread to these cavities.

The nasolacrimal duct is short, its external opening is located close to the corner of the eyelids, the valves are underdeveloped, which makes it very easy for infection to enter the conjunctival sac from the nose.

The pharynx in children is relatively narrow and has a more vertical direction. Waldeyer's ring in newborns is poorly developed; pharyngeal tonsils are not noticeable when examining the pharynx and become visible only by the end of the 1st year of life; in the following years, on the contrary, the accumulations of lymphoid tissue and tonsils hypertrophy somewhat, reaching maximum growth most often between 5 and 10 years. IN puberty tonsils begin to undergo reverse development, and after puberty it is comparatively very rare to see their hypertrophy. Enlargements of the adenoids are most pronounced in children with exudative and lymphatic diathesis; they especially often experience nasal breathing disorders, chronic catarrhal conditions of the nasopharynx, and sleep disturbances.

The larynx in very young children has a funnel-shaped shape, later - cylindrical; it is located slightly higher than in adults; its lower end in newborns is at the level of the fourth cervical vertebra (in adults, 1-12 vertebrae lower). The most vigorous growth of the transverse and anteroposterior dimensions of the larynx is observed in the 1st year of life and at the age of 14-16 years; With age, the funnel-shaped shape of the larynx gradually approaches cylindrical. The larynx in young children is relatively longer than in adults.

The cartilages of the larynx in children are tender and very pliable; the epiglottis is relatively narrow up to 12-13 years of age and infants it can be easily seen even with a routine examination of the pharynx.

Gender differences in the larynx in boys and girls begin to emerge only after 3 years, when the angle between the plates of the thyroid cartilage in boys becomes more acute. From the age of 10, boys already have quite clearly identified features characteristic of the male larynx.

The indicated anatomical and histological features of the larynx explain the mild onset of stenotic phenomena in children, even with relatively moderate inflammatory phenomena. Hoarseness, often observed in young children after a cry, usually does not depend on inflammatory phenomena, but on the lethargy of the easily fatigued muscles of the glottis.

The trachea in newborns has a length of about 4 cm, by 14-15 years it reaches approximately 7 cm, and in adults it is 12 cm. In children of the first months of life, it has a somewhat funnel-shaped shape and is located higher in them than in adults; in newborns, the upper end of the trachea is at the level of the IV cervical vertebra, in adults - at the level of VII.

The bifurcation of the trachea in newborns corresponds to the III-JV thoracic vertebrae, in 5-year-old children - IV-V and 12-year-olds - V-VI vertebrae.

The growth of the trachea is approximately parallel to the growth of the trunk; There is an almost constant relationship between the width of the trachea and the circumference of the chest at all ages. The cross section of the trachea in children in the first months of life resembles an ellipse, in subsequent ages it resembles a circle.

The tracheal mucosa is tender, rich in blood vessels and relatively dry due to insufficient secretion of mucous glands. The muscle layer of the membranous part of the tracheal wall is well developed even in newborns; elastic tissue is found in relatively small quantities.

A child's trachea is soft and easily compressed; under the influence of inflammatory processes, stenotic phenomena easily occur. The trachea is mobile to some extent and can be displaced under the influence of unilateral pressure (exudate, tumor).

Bronchi. The right bronchus is like a continuation of the trachea, the left one extends at a large angle; This explains the more frequent entry of foreign bodies into the right bronchus. The bronchi are narrow, their cartilage is soft, muscle and elastic fibers are relatively poorly developed, the mucous membrane is rich in blood vessels, but relatively dry.

The lungs of a newborn weigh about 50 g, by 6 months their weight doubles, by one year it triples, by 12 years it reaches 10 times its original weight; in adults, the lungs weigh almost 20 times more than at birth. The right lung is usually slightly larger than the left. In young children, the pulmonary fissures are often weakly expressed, only in the form of shallow grooves on the surface of the lungs; Especially often, the middle lobe of the right lung almost merges with the upper one. The large, or main, oblique fissure separates the lower lobe on the right from the upper and middle lobes, and the small horizontal fissure runs between the upper and middle lobes. There is only one slot on the left.

The differentiation of individual cellular elements must be distinguished from the growth of lung mass. The main anatomical and histological unit of the lung is the acinus, which, however, has a relatively primitive character in children under 2 years of age. From 2 to 3 years, cartilaginous muscular bronchi develop vigorously; from 6-7 years of age, the histostructure of the acinus basically coincides with that of an adult; The sacculi that are sometimes encountered no longer have a muscular layer. Interstitial (connective) tissue in children is loose and rich in lymphatic and blood vessels. The children's lung is poor in elastic tissue, especially around the alveoli.

The epithelium of the alveoli in non-breathing stillborns is cubic, in breathing newborns and in older children it is flat.

The differentiation of the children's lung is thus characterized by quantitative and qualitative changes: a decrease respiratory bronchioles, the development of alveoli from the alveolar ducts, an increase in the capacity of the alveoli themselves, the gradual reverse development of intrapulmonary connective tissue layers and the growth of elastic elements.

The volume of the lungs of already breathing newborns is 70 cm3, by the age of 15 their volume increases 10 times and in adults - 20 times. The overall growth of the lungs occurs mainly due to an increase in the volume of the alveoli, while the number of the latter remains more or less constant.

The breathing surface of the lungs in children is relatively larger than in adults; The contact surface of the alveolar air with the vascular pulmonary capillary system decreases relatively with age. The amount of blood flowing through the lungs per unit time is greater in children than in adults, which creates the most favorable conditions for gas exchange.

Children, especially young children, are prone to pulmonary atelectasis and hypostasis, the occurrence of which is favored by the richness of the lungs in blood and insufficient development of elastic tissue.

The mediastinum in children is relatively larger than in adults; in its upper part it contains the trachea, large bronchi, thymus gland and lymph nodes, arteries and large nerve trunks; in its lower part there is the heart, blood vessels and nerves.

The lymph nodes. Distinguish the following groups lymph nodes in the lungs: 1) tracheal, 2) bifurcation, 3) bronchopulmonary (at the point where the bronchi enter the lungs) and 4) nodes of large vessels. These groups of lymph nodes are connected by lymphatic tracts to the lungs, mediastinal and supraclavicular nodes.

Rib cage. Relatively large lungs, heart and mediastinum occupy relatively more space in the child's chest and determine some of its features. The chest is always in a state of inhalation, the thin intercostal spaces are smoothed out, and the ribs are pressed quite strongly into the lungs.

In very young children, the ribs are almost perpendicular to the spine, and increasing the capacity of the chest by raising the ribs is almost impossible. This explains the diaphragmatic nature of breathing at this age. In newborns and children in the first months of life, the anteroposterior and lateral diameters of the chest are almost equal, and the epigastric angle is very obtuse.

As the child ages, the cross-section of the chest takes on an oval or kidney-shaped shape.

The frontal diameter increases, the sagittal diameter decreases relatively, and the curvature of the ribs increases significantly; the epigastric angle becomes more acute.

These ratios are characterized by the chest indicator ( percentage between the anteroposterior and transverse diameters of the chest): in a fetus of the early embryonic period it is 185, in a newborn - 90, by the end of the year - 80, by 8 years - 70, after puberty it increases slightly again and fluctuates around 72-75 .

The angle between the costal arch and the medial section of the chest in a newborn is approximately 60°, by the end of the 1st year of life - 45°, at the age of 5 years - 30°, at 15 years - 20° and after the end of puberty - about 15 °.

The position of the sternum also changes with age; its upper edge, lying in a newborn at the level of the VII cervical vertebra, by 6-7 years of age drops to the level of the II-III thoracic vertebrae. The dome of the diaphragm, which reaches the upper edge of the fourth rib in infants, drops somewhat lower with age.

From the above it is clear that the chest in children gradually moves from the inspiratory position to the expiratory position, which is the anatomical prerequisite for the development of the thoracic (costal) type of breathing.

The structure and shape of the chest can vary significantly depending on the individual characteristics of the child. The shape of the chest in children is especially easily affected by past diseases (rickets, pleurisy) and various negative effects. environment. Age-related anatomical features of the chest also determine some physiological features of the breathing of children in different periods childhood.

The first breath of a newborn. During the period of intrauterine development in the fetus, gas exchange occurs exclusively due to the placental circulation. At the end of this period, the fetus develops regular intrauterine respiratory movements, indicating the ability respiratory center react to irritation. From the moment the baby is born, gas exchange stops due to the placental circulation and pulmonary respiration begins.

The physiological causative agent of the respiratory center is a lack of oxygen and carbon dioxide, the increased accumulation of which from the moment of cessation of placental circulation is the cause of the first deep breath of the newborn; it is possible that the cause of the first breath should be considered not so much an excess of carbon dioxide in the blood of a newborn, but mainly a lack of oxygen in it.

The first breath, accompanied by the first cry, in most cases appears in the newborn immediately - as soon as the passage of the fetus through the birth canal mother. However, in cases where a child is born with a sufficient supply of oxygen in the blood or there is a slightly reduced excitability of the respiratory center, several seconds, and sometimes even minutes, pass until the first breath appears. This short-term holding of breath is called neonatal apnea.

After the first deep breath, healthy children establish correct and mostly fairly uniform breathing; The uneven breathing rhythm observed in some cases during the first hours and even days of a child’s life usually quickly levels out.

The respiratory rate in newborns is about 40-60 per minute; With age, breathing becomes more rare, gradually approaching the rhythm of an adult. According to our observations, the respiratory rate in children is as follows.

Children's age

Until the age of 8, boys breathe more frequently than girls; In the prepubertal period, girls are ahead of boys in breathing frequency, and in all subsequent years their breathing remains more frequent.

Children are characterized by mild excitability of the respiratory center: mild physical stress and mental arousal, slight increases in body temperature and ambient air almost always cause a significant increase in breathing, and sometimes some disruption of the correct respiratory rhythm.

On average, one respiratory movement in newborns accounts for 2'/2-3 pulse beats, in children at the end of the 1st year of life and older - 3-4 beats, and, finally, in adults - 4-5 heart beats. These ratios usually persist when heart rate and breathing increase under the influence of physical and mental stress.

Breath volume. To assess the functional capacity of the respiratory organs, the volume of one respiratory movement, minute volume of breathing and vital capacity of the lungs are usually taken into account.

The volume of each respiratory movement in a newborn in a state of quiet sleep is on average 20 cm3, in a one-month-old child it increases to approximately 25 cm3, by the end of the year reaches 80 cm3, by 5 years - about 150 cm3, by 12 years - on average about 250 cm3 and by 14-16 years it increases to 300-400 cm3; however, this value, apparently, can fluctuate within fairly wide individual limits, since the data of different authors differ greatly. When screaming, the volume of breathing increases sharply - 2-3 and even 5 times.

The minute volume of breathing (the volume of one breath multiplied by the number of respiratory movements) quickly increases with age and is approximately equal to 800-900 cm3 in a newborn, 1400 cm3 in a child aged 1 month, by the end of the 1st year - about 2600 cm3, in at the age of 5 years - about 3200 cm3 and at 12-15 years - about 5000 cm3.

The vital capacity of the lungs, i.e., the amount of air maximally exhaled after maximal inhalation, can only be indicated for children starting from 5-6 years old, since the research methodology itself requires the active participation of the child; at 5-6 years old, the vital capacity fluctuates around 1150 cm3, at 9-10 years old - about 1600 cm3, and at 14-16 years old - 3200 cm3. Boys have a larger lung capacity than Girls; The greatest lung capacity occurs with thoracoabdominal breathing, the smallest with purely chest breathing.

The type of breathing varies depending on the age and gender of the child; In children of the newborn period, diaphragmatic breathing predominates with little participation of the costal muscles. In children infancy so-called thoracic-abdominal breathing with a predominance of diaphragmatic breathing is detected; excursions of the chest are weakly expressed in its upper parts and, conversely, much stronger in the lower parts. As the child moves from a constant horizontal position to a vertical position, the type of breathing also changes; at this age (the beginning of the 2nd year of life) it is characterized by a combination of diaphragmatic and chest breathing, and in some cases one predominates, in others the other. At the age of 3-7 years due to muscle development shoulder girdle Chest breathing is becoming more and more clearly visible, beginning to definitely dominate over diaphragmatic breathing.

The first differences in the type of breathing depending on gender begin to clearly appear at the age of 7-14 years; During the prepubertal and pubertal periods, boys develop mainly the abdominal type, and girls develop the thoracic type of breathing. Age-related changes The type of breathing is predetermined by the above-mentioned anatomical features of the chest of children at different periods of life.

Increasing the capacity of the chest by raising the ribs in infants is almost impossible due to the horizontal position of the ribs; it becomes possible in later periods, when the ribs drop somewhat downwards and anteriorly and when they are raised, the anteroposterior and lateral dimensions of the chest increase.

Features of breathing regulation

As is known, the act of breathing is regulated by the respiratory center, whose activity is characterized by automaticity and rhythm. The respiratory center is located in the middle third of the medulla oblongata on either side of the midline. Excitation, rhythmically arising in the cells of the respiratory center, along centrifugal (efferent) nerve pathways transmitted to the respiratory muscles. Various irritations affecting the extero- and interoreceptors of the human body travel through centripetal pathways to the respiratory center and affect the processes of excitation and inhibition that occur in it; The role of impulses coming from the lungs themselves is especially great when irritating numerous receptors embedded in the bronchioles and alveoli; the excitation that occurs during inhalation in these interoreceptors along the fibers vagus nerve transmitted to the respiratory center and inhibits its activity; the inhibited center does not send exciting impulses to the respiratory muscles, and they relax, and the exhalation phase begins; in a collapsed lung, the afferent endings of the vagus nerve are not excited, therefore, the inhibitory influence coming through its fibers is eliminated, the respiratory center is excited again, the resulting impulses are sent to the respiratory muscles and a new breath occurs; self-regulation occurs: inhalation causes exhalation, and the latter causes inhalation. Of course, the composition of the alveolar air also plays a role.

Consequently, the regulation of breathing in children is carried out mainly by the neuro-reflex pathway. Irritation of the endings of the centripetal nerves of the skin, muscles, vascular reflexogenic zones, endings of the sinocarotid nerve, etc., in the same reflex way, affects the rhythm and depth of breathing. The composition of the blood, the content of oxygen and carbon dioxide in it, the reaction of the blood, the accumulation of lactic acid or various pathological metabolic products in it also affect the function of the respiratory center; these irritations can be transmitted to it as a result of the influence of the blood composition on the receptors embedded in the walls of the vessels themselves, as well as as a result of the direct effect on the respiratory center of the composition of the blood washing it (humoral influence).

The function of the respiratory center of the medulla oblongata is constantly regulated by the cerebral cortex. The rhythm of breathing and its depth change under the influence of various emotional moments; an adult and older children can voluntarily change both the depth and frequency of breathing and can hold it for some time. Experiments on animals and observations in humans have proven the possibility of conditioned reflex effects on breathing. All this speaks to the regulatory role of the cerebral cortex. In very young children, it is often necessary to observe disturbances in the rhythm of breathing, even short-term complete cessation of breathing, for example in premature infants, which must be explained by the morphological immaturity of their central and peripheral nervous systems and, in particular, the cerebral cortex. A slight disturbance in the rhythm of breathing during sleep and in older children must be explained by the unique relationship between the cortex and the subcortical region of the brain.

The regulatory role of the central nervous system ensures the integrity of the body and explains the dependence of breathing on the function of other organs - the circulatory system, digestion, blood system, metabolic processes, etc. The close dependence of the function of some organs on the function of others is especially pronounced in children with less perfect regulation cortico-visceral connections.

Protective reflexes from the mucous membranes of the respiratory tract - sneezing and coughing - are expressed, although less clearly, already in children of the newborn period.

The formation of the tracheopulmonary system begins at 3-4 weeks embryonic development. Already by the 5th-6th week of embryo development, second-order branches appear 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, 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. Growth occurs within 3 months bronchial tree, segmental and sub segmental bronchi.

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 young children.

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 intensive growth of the pulmonary 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 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 lung tissue elements and blood vessels occur. 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.

Features of the child's respiratory tract

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 of carbon dioxide occurs in dissolved form; blood saturation 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, 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.

With respiratory diseases in children, respiratory dysfunction and respiratory failure may occur.

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 and well supplied with 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 a disturbance in appetite, as well as a disturbance in the understanding of the 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 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 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: its narrow lumen, 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 located at the level of the 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 a 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 of the bronchopulmonary system are less common compared to children of younger ages.

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: 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 minute. Lung development is completed by age 20.

A variety of diseases can impair 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 a supine state in infants 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, bronchological, determination gas composition blood, 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 is judged (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 respiration, that is, 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 the 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 is very important. It warms, moisturizes and cleanses (which helps preserve tooth enamel) the air passing into the lungs irritates nerve endings, which 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.

The main vital function of the respiratory organs is to provide tissues with oxygen and remove carbon dioxide.

The respiratory organs consist of air-conducting (respiratory) tracts and paired respiratory organs - the lungs. The respiratory tract is divided into upper (from the opening of the nose to the vocal cords) and lower (larynx, trachea, lobar and segmental bronchi, including intrapulmonary branches of the bronchi). By the time the child is born, their morphological structure is still imperfect, which is also associated with the functional characteristics of breathing.

Intensive growth and differentiation of the respiratory organs continues during the first months and years of life. The formation of the respiratory organs ends on average by the age of 7, and only their sizes subsequently increase.

Anatomical and physiological features. All airways in a child are significantly smaller and have narrower openings than in an adult.

The features of their morphological structure in children of the first years of life are the following:

1) thin, delicate, easily wounded dry mucous membrane with insufficient development of glands, reduced production of secretory immunoglobulin A (SIg A) and surfactant deficiency;

2) rich vascularization of the submucosal layer, represented predominantly by loose fiber and containing few elastic and connective tissue elements;

3) softness and pliability of the cartilaginous frame lower sections respiratory tract, lack of elastic tissue in them and lungs.

This reduces the barrier function of the mucous membrane, facilitates easier penetration of the infectious agent into the bloodstream, and also creates the preconditions for narrowing of the airways due to rapidly occurring swelling or compression of the pliable respiratory tubes from the outside ( thymus gland, abnormally located vessels, enlarged tracheobronchial lymph nodes).

Nose and nasopharyngeal space. In young children, the nose and nasopharyngeal space are small, the nasal cavity is low and narrow due to insufficient development of the facial skeleton. The shells are thick, the nasal passages are narrow, the lower one is formed only by 4 years. Even slight hyperemia and swelling of the mucous membrane during a runny nose makes the nasal passages obstructed, causes shortness of breath, and makes breastfeeding difficult. Cavernous tissue develops by the age of 8-9 years, so nosebleeds in young children are rare and caused by pathological conditions. During puberty they are observed more often.

Paranasal (paranasal) sinuses. By the birth of the child, only the maxillary (maxillary) sinuses are formed; The frontal and ethmoid are open protrusions of the mucous membrane, taking shape in the form of cavities only after 2 years; the main sinus is absent. All paranasal sinuses develop completely by the age of 12-15, however, sinusitis can also develop in children in the first two years of life.
Nasolacrimal duct. It is short, its valves are underdeveloped, the outlet is located close to the corner of the eyelids, which facilitates the spread of infection from the nose to the conjunctival sac.

Pharynx.
In young children, the pharynx is relatively wide, tonsils at birth they are clearly visible, but do not protrude due to well-developed arches. Their crypts and vessels are poorly developed, which to some extent explains rare diseases sore throat in the first year of life. By the end of the first year lymphoid tissue tonsils, including the nasopharyngeal tonsils (adenoids), often hyperplasia, especially in children with diathesis. Their barrier function at this age is low, like that of lymph nodes. The overgrown lymphoid tissue is populated by viruses and microorganisms, and foci of infection are formed - adenoiditis and chronic tonsillitis. In this case, frequent sore throats and acute respiratory viral infections are observed, nasal breathing is often disrupted, the facial skeleton changes and an “adenoid face” is formed.

Epiglottis.
Closely related to the root of the tongue. In newborns it is relatively short and wide. The incorrect position and softness of its cartilage can cause a functional narrowing of the entrance to the larynx and the appearance of noisy (stridor) breathing.

Larynx. In children, the larynx is higher than in adults, it descends with age, and is very mobile. Its position is not constant even in the same patient. It has a funnel-shaped shape with a distinct narrowing in the area of ​​the subglottic space, limited by the rigid cricoid cartilage. The diameter of the larynx in this place in a newborn is only 4 mm and increases slowly (6-7 mm at 5-7 years, 1 cm by 14 years), its expansion is impossible. A narrow lumen, an abundance of nerve receptors in the subglottic space, and easily occurring swelling of the submucosal layer can cause severe breathing problems even with minor manifestations respiratory infection(croup syndrome).

The thyroid cartilages form a blunt, rounded angle in young children, which becomes sharper in boys after 3 years of age. From the age of 10, the characteristic male larynx is formed. True vocal cords in children it is shorter than in adults, which explains the height and timbre of the child’s voice.

Trachea.
In children in the first months of life, the trachea is often funnel-shaped; at older ages, cylindrical and conical shapes predominate. Its upper end is located in newborns much higher than in adults (at the level of the IV and VI cervical vertebrae, respectively), and gradually descends, like the level of the tracheal bifurcation (from the III thoracic vertebra in a newborn to V-VI at 12-14 years). The tracheal framework consists of 14-16 cartilaginous half-rings connected posteriorly by a fibrous membrane (instead of an elastic end plate in adults). The membrane contains many muscle fibers, the contraction or relaxation of which changes the lumen of the organ.

The child’s trachea is very mobile, which, along with the changing lumen and softness of the cartilage, sometimes leads to a slit-like collapse during exhalation (collapse) and is the cause of expiratory shortness of breath or rough snoring breathing (congenital stridor). Symptoms of stridor usually disappear by age 2 as the cartilage becomes denser.

Bronchial tree.
By the time of birth, the bronchial tree is formed. As the child grows, the number of branches and their distribution in the lung tissue do not change. The size of the bronchi increases rapidly in the first year of life and during puberty. They are also based on cartilaginous semirings, in early childhood without a closing elastic plate, connected by a fibrous membrane containing muscle fibers. The cartilage of the bronchi is very elastic, soft, springy and easily displaced. The right main bronchus is usually an almost direct continuation of the trachea, so it is in it that foreign bodies are most often found.

The bronchi, like the trachea, are lined with multirow cylindrical epithelium, the ciliated apparatus of which is formed after the birth of the child. Hyperemia and swelling of the bronchial mucosa, its inflammatory swelling significantly narrow the lumen of the bronchi, up to their complete obstruction. Thus, with an increase in the thickness of the submucosal layer and mucous membrane by 1 mm, the total area of ​​the bronchial lumen of a newborn decreases by 75% (in an adult - by 19%). Active bronchial motility is insufficient due to poor development of muscles and ciliated epithelium.

Incomplete myelination of the vagus nerve and underdevelopment of the respiratory muscles contribute to the weakness of the cough impulse in a small child; Infected mucus accumulating in the bronchial tree clogs the lumens of the small bronchi, promotes atelectasis and infection of the lung tissue. So the main functional feature of the bronchial tree of a small child is the insufficient performance of the drainage and cleansing function.

Lungs.
In children, as in adults, the lungs have a segmental structure. The segments are separated from each other by narrow grooves and layers of connective tissue (lobular lung). The main structural unit is the acini, but its terminal bronchioles end not in a cluster of alveoli, as in an adult, but in a sac (sacculus). New alveoli are gradually formed from the “lace” edges of the latter, the number of which in a newborn is 3 times less than in an adult. The diameter of each alveoli also increases (0.05 mm in a newborn, 0.12 mm at 4-5 years, 0.17 mm at 15 years). At the same time, the vital capacity of the lungs increases.

The interstitial tissue in a child's lung is loose, rich in blood vessels, fiber, and contains very little connective tissue and elastic fibers. In this regard, the lungs of a child in the first years of life are more full-blooded and less airy than those of an adult. Underdevelopment of the elastic framework of the lungs contributes to both the occurrence of emphysema and atelectasis of the lung tissue. Atelectasis occurs especially often in the posterior regions of the lungs, where hypoventilation and blood stagnation are constantly observed due to the forced horizontal position of a small child (mainly on the back).

The tendency to atelectasis is enhanced by a deficiency of surfactant, a film that regulates alveolar surface tension and is produced by alveolar macrophages. It is this deficiency that leads to insufficient expansion of the lungs in premature infants after birth (physiological atelectasis), and also underlies the respiratory distress syndrome, clinically manifested by severe respiratory failure.
Pleural cavity. In a child, it is easily extensible due to weak attachment of the parietal layers. The visceral pleura, especially in newborns, is relatively thick, loose, folded, contains villi and outgrowths, most pronounced in the sinuses and interlobar grooves. In these areas there are conditions for more rapid occurrence infectious foci.

Root of the lung.
Consists of large bronchi, vessels and lymph nodes (tracheobronchial, bifurcation, bronchopulmonary and around large vessels). Their structure and function are similar to peripheral lymph nodes. They easily respond to the introduction of infection - a picture of both nonspecific and specific (tuberculous) bronchoadenitis is created. The root of the lung is integral part mediastinum.

The latter is characterized by easy displacement and is often the site of development of inflammatory foci, from where the infectious process spreads to the bronchi and lungs. The mediastinum also contains the spectacle gland (thymus), which at birth has big sizes and normally decreases gradually during the first two years of life. Enlarged thymus can cause compression of the trachea and large vessels, impair breathing and blood circulation.

Diaphragm.
Due to the characteristics of the chest, the diaphragm plays a large role in the breathing mechanism of a small child, ensuring the depth of inspiration. The weakness of its contractions partly explains the extremely shallow breathing of the newborn. Any processes that impede the movement of the diaphragm (formation of a gas bubble in the stomach, flatulence, intestinal paresis, enlargement of parenchymal organs, intoxication, etc.) reduce ventilation of the lungs (restrictive respiratory failure).

The main functional physiological features of the respiratory organs are the following:

1) the depth of breathing, the absolute and relative volumes of one respiratory act in a child are significantly less than in an adult. With age, these figures gradually increase. When screaming, the volume of breathing increases 2-5 times. The absolute value of the minute volume of respiration is less than that of an adult, and the relative value (per 1 kg of body weight) is much greater;

2) the respiratory rate increases, the younger the child. It compensates for the small volume of each respiratory act and provides oxygen to the child’s body. Rhythm instability and short (3-5 min) pauses in breathing (apnea) in newborns and premature infants are associated with incomplete differentiation of the respiratory center and its hypoxia. Oxygen inhalation usually eliminates respiratory arrhythmia in these children;

3) gas exchange in children is carried out more vigorously than in adults, due to the rich vascularization of the lungs, blood flow speed, and high diffusion capacity. At the same time, the function of external respiration in a small child is disrupted very quickly due to insufficient excursion of the lungs and straightening of the alveoli.

Swelling of the epithelium of the alveoli or interstitium of the lungs, exclusion of even a small area of ​​lung tissue from the act of breathing (atelectasis, congestion in the posterior regions of the lungs, focal pneumonia, restrictive changes) reduce pulmonary ventilation, cause hypoxemia and accumulation of carbon dioxide in the blood, i.e., the development of respiratory failure, as well as respiratory acidosis. Tissue respiration occurs in a child at higher energy costs than in adults, and is easily disrupted with the formation metabolic acidosis due to the instability of enzyme systems characteristic of early childhood.

Research methodology.
When assessing the condition of the respiratory organs, questioning (usually the mother) and objective methods are used - examination and counting the number of respiratory movements, palpation, percussion, auscultation, as well as laboratory and instrumental studies.

Questioning. The mother is asked how the perinatal period and childbirth proceeded, what the child was sick with, including shortly before the present illness, what symptoms were observed at the onset of the illness. Pay special attention to nasal discharge and difficulty in nasal breathing, the nature of cough (periodic, paroxysmal, barking, etc.) and breathing (hoarse, whistling, audible at a distance, etc.), as well as contacts with patients with respiratory or other acute or chronic infection.

Visual inspection. Examination of the face, neck, chest, and limbs provides more information the younger the child. Pay attention to the child’s scream, voice and cough. The examination helps to identify, first of all, signs of hypoxemia and respiratory failure - cyanosis and shortness of breath.
Cyanosis may be pronounced in certain areas ( nasolabial triangle, fingers) and be widespread. With advanced microcirculation disorders, a rough cyanotic (marble) pattern on the skin is observed. Cyanosis may appear during crying, swaddling, feeding, or be constant.

Expansion of the superficial capillary network in the area of ​​the VII cervical vertebra (Frank's symptom) may indicate an enlargement of the tracheobronchial lymph nodes. Pronounced vasculature on the skin of the chest is sometimes an additional symptom of hypertension in the pulmonary artery system.
Dyspnea is often accompanied by the participation of accessory muscles and retraction of the compliant areas of the chest.
Inspiratory dyspnea with difficult, sonorous, sometimes whistling inhalation is observed with croup syndrome and any obstruction of the upper respiratory tract.

Expiratory shortness of breath with difficulty and prolongation of exhalation is characteristic of obstructive bronchitis, bronchial asthma, bronchiolitis, viral respiratory syncytial infection, significant enlargement of tracheobronchial lymph nodes.

Mixed shortness of breath is observed with pneumonia, pleurisy, circulatory disorders, restrictive respiratory failure (severe flatulence, ascites). Puffing shortness of breath of a mixed nature is observed in severe rickets.

Swelling and tension of the wings of the nose indicate difficulty breathing and are the equivalent of shortness of breath in newborns and children in the first months of life.

It is also necessary to pay attention to nasal discharge and its nature. Bloody, especially unilateral, discharge can be observed with a foreign body in the nasal passages or nasal diphtheria. Pink foam coming from the nose and mouth is one of the symptoms acute pneumonia in newborns.

The child's voice allows us to judge the condition of the upper respiratory tract. A hoarse, low-pitched voice or complete aphonia is characteristic of laryngitis and croup syndrome. A rough, low voice is characteristic of hypothyroidism. The voice acquires a nasal, nasal tone when chronic runny nose, adenoids, paresis of the velum palatine (due to birth trauma, poliomyelitis, diphtheria), tumors and abscesses of the pharynx, congenital defects of the upper jaw.
The cry of a healthy full-term baby is loud, sonorous, promotes the straightening of lung tissue and the disappearance of atelectasis. A premature and weakened baby has a weak cry. Crying after feeding, before defecation, during urination requires, accordingly, the exclusion of hypo-galactia, fissures anus, phimosis, vulvitis and urethritis. A periodic loud cry is often observed with otitis, meningitis, abdominal pain, a monotonous, inexpressive “brain” cry - with organic damage to the central nervous system.

Cough- a very valuable diagnostic sign. To artificially induce a cough, you can press on the cartilage of the trachea, the root of the tongue, or irritate the pharynx. A barking, rough cough that gradually loses sonority is characteristic of croup syndrome. A paroxysmal, prolonged cough consisting of successive cough shocks, accompanied by a loud, difficult inhalation (reprise) and ending with vomiting, is observed with whooping cough.

Bitonal cough is characteristic of enlarged tracheobronchial and bifurcation intrathoracic lymph nodes. Short painful cough with groaning exhalation often occurs with pleuropneumonia; dry, painful - with pharyngitis, tracheitis, pleurisy; wet - for bronchitis, bronchiolitis. It must be remembered that swelling of the mucous membrane of the nasopharynx, enlarged adenoids, and excessive mucus formation can cause a persistent cough, especially when changing position and without affecting the underlying respiratory tract.

Counting the number of respiratory movements should be carried out at the beginning of the examination in a state of rest (or sleep), since the child easily experiences tachypnea under any influence, including emotional. Brady pnea is rare in children (with meningitis and other brain lesions, uremia). In cases of severe intoxication, the breathing of a “hunted animal” is sometimes observed - frequent and deep. The count is made within a minute, better in sleeping children and by breathing sounds, through a phonendoscope brought to the nose. In older children, counting is done with a hand placed on the chest and stomach at the same time (on the costal arch), since children are characterized by abdominal or mixed types of breathing. The respiratory rate of a newborn child is 40-60 per minute, a one-year-old child is 30-35, 5-6 years old is 20-25, 10 years old is 1R-20, an adult is 15-16 per minute.

Palpation.
Palpation reveals chest deformities (congenital, associated with rickets or other bone formation defects). In addition, the thickness of the skin fold is determined symmetrically on both sides of the chest and the bulging or retraction of the intercostal spaces, the lag of one half of the chest during breathing. Swelling of the fiber, a thicker fold on one side, bulging of the intercostal spaces are characteristic of exudative pleurisy. Recession of the intercostal spaces can be observed with atelectasis and adhesive processes in the cavity of the pleura and pericardium.

Percussion.
In children, percussion has a number of features:

1) the position of the child’s body should ensure maximum symmetry of both halves of the chest. Therefore, the back is percussed with the child standing or sitting with legs crossed or extended, side surfaces chest - in a standing or sitting position with hands on the back of the head or extended forward, and the chest - lying down;

2) percussion should be quiet - finger on finger or direct, since the chest of a child resonates much more than that of an adult;

3) the pessimeter finger is located perpendicular to the ribs, which creates conditions for a more uniform formation of percussion tone.

The percussion tone in a healthy child of the first years of life is usually high, clear, with a slightly boxy tint. When screaming, it can change - from distinct tympanitis at maximum inspiration and shortening during exhalation.

Any stable change in the nature of the percussion tone should alert the doctor. For bronchitis, bronchiolitis, asthmatic syndrome and asthma, and often bronchopneumonia with small-sized foci of compaction of lung tissue and vicarious emphysema, a box or high-pitched tympanic sound may occur. With pneumonia, especially prolonged and chronic ones, a “variegated” sound is possible - alternating areas of shortening of the tone and percussion tympanic sound. Significant local or total shortening of tone indicates massive (lobar, segmental) pneumonia or pleurisy. Enlargement of the tracheobronchial lymph nodes is detected by direct percussion along the spinous processes of the vertebrae, starting from the lower thoracic regions.

Shortening of the sound below the second thoracic vertebra indicates possible bronchoadenitis (Coranyi de la Campa symptom).

The boundaries of the lungs are determined along the same lines as in adults, on average 1 cm higher due to the higher position of the diaphragm (in children of early and early childhood) preschool age). The mobility of the pulmonary edge is determined when the child breathes freely.

Auscultation. Features of the technique: 1) strictly symmetrical position of both halves of the chest, similar to that during percussion; 2) the use of a special children's stethoscope - with long tubes and a small diameter, since the membrane can distort the sound.

The normal respiratory sounds heard depend on age: up to 6 months in a healthy child, breathing is weakened vesicular due to its superficial nature; at the age of 6 months - 7 years, puerid (children's) breathing is heard, with a more distinct inhalation and a relatively louder and longer exhalation. In school-age children and adolescents, breathing is the same as in adults - vesicular (the ratio of the duration of inhalation and exhalation is 3:1). When a child is crying, auscultation is no less valuable than at rest. When screaming, the depth of inspiration increases, bronchophony is well defined, increasing over areas of compaction of the lung tissue, and various wheezing sounds are heard.

Pathological breathing sounds include the following types of breathing:

1) bronchial (the ratio of the duration of inhalation and exhalation is 1:1), observed during infiltration of the lung tissue and above the zone of the lung pressed with liquid or air, while an extended exhalation indicates bronchospasm;

2) weakened vesicular in children older than one year with pleurisy, tuberculous infiltration of lung tissue, painful inhalation (with a rib fracture, myositis, appendicitis, peritonitis), severe bronchial obstruction, foreign body;

3) amphoric, heard over bullous (with destructive pneumonia) and other cavities in the lungs.

Wheezing is heard during various pathological processes in the bronchi and lungs, most often at the depth of inspiration. Dry wheezing of a conductive nature (rough, sonorous, whistling) is heard with laryngitis, pharyngitis, tracheitis, asthmatic bronchitis, foreign body, attack of bronchial asthma. In the latter case, they can be heard at a distance. Moist rales - large and medium bubble - indicate damage to the bronchi; small, voiced ones are formed in the bronchioles, crepitants - in the alveoli.

The prevalence and stability of auscultation of wheezes are of diagnostic importance: small and crepitating wheezes detected locally over a long period of time are more likely to indicate a pneumonic focus. Diffuse, intermittent, variable-caliber moist rales are more typical of bronchitis or bronchiolitis.

Bronchoadenitis is characterized by D'Espina's symptom - clear auscultation of whispered speech over the spinous processes below the first thoracic vertebra. Pleural friction noise is detected in pleurisy and is characterized in children by instability and a transient nature.
The oropharynx is the last place to be examined in a child. The patient’s head and hands are securely fixed by the mother or a nurse; first, the mucous membrane of the cheeks, gums, teeth, tongue, hard and soft palate are examined using a spatula. Then use a spatula to press down on the root of the tongue and examine the palatine tonsils, arches, and the back wall of the pharynx. In young children, the epiglottis can often be examined. The main signs of damage to the oropharynx, which have diagnostic value, see Digestive and abdominal organs.
Laboratory and instrumental research.

The following studies are of greatest diagnostic importance:
1) x-ray;
2) bronchological;
3) determination of gas composition, blood pH, acid-base balance;
4) external respiration functions;
5) analysis of bronchial secretions.

The features of instrumental and laboratory research in pediatric practice are the following:
1) technical difficulties of bronchological examination associated with the small size of the airways;
2) the use of general anesthesia, especially in young children, for bronchoscopy and bronchography;
3) mandatory participation in the bronchological examination of specialists - pediatrician, pediatric bronchopulmonologist, anesthesiologist;
4) the impossibility of using the most common spirographic determination of external respiration function in children under 5-6 years of age and the use of pneumography and general plethysmography in this group of patients;
5) difficulties in conducting gas analytical studies in newborns and children under 3 years of age due to rapid breathing and a negative attitude towards the methods used.

In development respiratory system There are several stages:

Stage 1 – before the 16th week of 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 with a thin layer; during inhalation, the volume of the alveoli increases, surface tension increases, which leads to breathing 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, and during cesarean 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 according to the type of gasping (inspiratory “flash”) - this is deep breath with difficulty breathing. Such breathing persists in healthy full-term infants until the first 3 hours of life. U healthy newborn With the child's 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 has an environmental temperature that 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 baby has well-expressed protective reflexes - coughing and sneezing. Already in the first days after the birth of a child, the Hering-Breuer reflex functions, which, at threshold stretching of the pulmonary alveoli, leads 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, there is no lower nasal passage, turbinate, which are formed by the age of 4. 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 in children in the first six months of life is impossible, since big tongue pushes the epiglottis posteriorly. 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 the facial bones increase in size ( 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. During puberty, the tonsils begin to undergo reverse development. The Eustachian tubes in young children are wide, short, straight, located horizontally and at horizontal position child, the 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 entry of a 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 bronchial mucosa 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 an 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, directed with its apex towards root of the lung, 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 - 1, 2 and 3rd, the 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.

d) 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).