The human respiratory system diagram. Respiratory organs and their functions: nasal cavity, larynx, trachea, bronchi, lungs. Respiratory tract pathologies

Functions of the respiratory system

STRUCTURE OF THE RESPIRATORY SYSTEM

Control questions

1. What organs are called parenchymal?

2. What membranes are isolated in the walls of hollow organs?

3. What organs form the walls of the oral cavity?

4. Tell us about the structure of the tooth. How do different types of teeth differ in shape?

5. What are the terms of eruption of milk and permanent teeth. Write the complete formula of milk and permanent teeth.

6. What papillae are there on the surface of the tongue?

7. Name the anatomical muscle groups of the tongue, the function of each muscle of the tongue.

8. List the groups of small salivary glands. Where do the ducts of the major salivary glands open in the oral cavity?

9. Name the muscles of the soft palate, their places of origin and attachment.

10. In what places does the esophagus have narrowings, what causes them?

11. At the level of which vertebrae are the entrance and exit openings of the stomach located? Name the ligaments (peritoneal) of the stomach.

12. Describe the structure and functions of the stomach.

13. What is the length and thickness of the small intestine?

14. What anatomical formations are visible on the surface of the mucous membrane of the small intestine throughout its entire length?

15. How does the structure of the large intestine differ from the small intestine?

16. Where on the front abdominal wall converge lines of projections of the upper and lower boundaries of the liver? Describe the structure of the liver and gallbladder.

17. What organs does the visceral surface of the liver come into contact with? Name the size and volume of the gallbladder.

18. How is digestion regulated?

1. Supplying the body with oxygen and removing carbon dioxide;

2. Thermoregulatory function (up to 10% of the heat in the body is spent on the evaporation of water from the surface of the lungs);

3. Excretory function - removal of carbon dioxide, water vapor, volatile substances (alcohol, acetone, etc.) with exhaled air;

4. Participation in water exchange;

5. Participation in maintaining acid-base balance;

6. The largest blood depot;

7. Endocrine function - hormone-like substances are formed in the lungs;

8. Participation in sound reproduction and speech formation;

9. Protective function;

10. Perception of smells (smell), etc.

Respiratory system ( systems respiratorium) comprises respiratory tract and paired respiratory organs - lungs (Fig. 4.1; Table 4.1). The airways are divided into upper and lower airways according to their position in the body. lower divisions. The upper respiratory tract includes the nasal cavity, bow pharynx, oral part of the pharynx, to the lower respiratory tract - larynx, trachea, bronchi, including intrapulmonary branches of the bronchi.

Rice. 4.1. Respiratory system. 1 - oral cavity; 2 - nasal part of the pharynx; 3 - soft palate; 4 - language; 5 - oral part of the pharynx; 6 - epiglottis; 7 - guttural part of the pharynx; 8 - larynx; 9 - esophagus; 10 - trachea; 11 - the top of the lung; 12 - upper lobe left lung; 13 - left main bronchus; 14 - lower lobe of the left lung; 15 - alveoli; 16 - right main bronchus; 17 - right lung; 18 - hyoid bone; 19 - lower jaw; 20 - vestibule of the mouth; 21 - oral fissure; 22 - hard palate; 23 - nasal cavity

The respiratory tract consists of tubes, the lumen of which is preserved due to the presence of a bone or cartilaginous skeleton in their walls. This morphological feature is fully consistent with the function of the respiratory tract - conducting air into the lungs and out of the lungs. The inner surface of the respiratory tract is covered with a mucous membrane, which is lined with ciliated epithelium, contains significant

Table 4.1. The main characteristic of the respiratory system

the number of glands that secrete mucus. Due to this, it performs a protective function. Passing through the respiratory tract, the air is purified, warmed and humidified. In the process of evolution, the larynx was formed on the path of the air stream - a complex organ that performs the function of voice formation. Through the respiratory tract, air enters the lungs, which are the main organs of the respiratory system. In the lungs, gas exchange occurs between air and blood by diffusion of gases (oxygen and carbon dioxide) through the walls of the pulmonary alveoli and adjacent blood capillaries.

nasal cavity (cavitalis nasi) includes the external nose and the nasal cavity proper (Fig. 4.2).

Rice. 4.2. Nasal cavity. Sagittal section.

External nose includes the root, back, apex and wings of the nose. nose root located in the upper part of the face and separated from the forehead by a notch - the nose bridge. The sides of the external nose are connected along the midline and form the back of the nose, and the lower parts of the sides are the wings of the nose, which limit the nostrils with their lower edges , serving for the passage of air into the nasal cavity and out of it. Along the midline, the nostrils are separated from each other by the movable (webbed) part of the nasal septum. The external nose has a bone and cartilaginous skeleton formed by the nasal bones, frontal processes upper jaws and several hyaline cartilages.

The actual nasal cavity divided by the nasal septum into two almost symmetrical parts, which open in front on the face with nostrils , and behind through the choanae , communicate with the nasal part of the pharynx. In each half of the nasal cavity, a nasal vestibule is isolated, which is bounded from above by a small elevation - the threshold of the nasal cavity, formed by the upper edge of the large cartilage of the wing of the nose. The vestibule is covered from the inside by the skin of the external nose continuing here through the nostrils. The skin of the vestibule contains sebaceous, sweat glands and hard hair - vibris.

Most of The nasal cavity is represented by the nasal passages, with which the paranasal sinuses communicate. There are upper, middle and lower nasal passages, each of them is located under the corresponding nasal concha. Behind and above the superior turbinate is a sphenoid-ethmoid depression. Between the nasal septum and the medial surfaces of the turbinates is a common nasal passage, which looks like a narrow vertical slit. The posterior cells of the ethmoid bone open into the upper nasal passage with one or more openings. The lateral wall of the middle nasal passage forms a rounded protrusion towards the nasal concha - a large ethmoid vesicle. In front and below the large ethmoid vesicle there is a deep semilunar cleft , through which the frontal sinus communicates with the middle nasal passage. Middle and anterior cells (sinuses) of the ethmoid bone, frontal sinus, maxillary sinus open into the middle nasal passage. The lower opening of the nasolacrimal duct leads to the inferior nasal passage.

Nasal mucosa continues into the mucous membrane of the paranasal sinuses, lacrimal sac, nasal part of the pharynx and soft palate (through the choanae). It is tightly fused with the periosteum and perichondrium of the walls of the nasal cavity. In accordance with the structure and function, the olfactory mucosa is distinguished in the mucous membrane of the nasal cavity (the part of the membrane covering the right and left upper nasal conchas and part of the middle ones, as well as the corresponding upper section nasal septum containing olfactory neurosensory cells) and the respiratory region (the rest of the nasal mucosa). The mucous membrane of the respiratory region is covered with ciliated epithelium, it contains mucous and serous glands. In the region of the lower shell, the mucous membrane and submucosa are rich in venous vessels, which form cavernous venous plexuses of the shells, the presence of which contributes to the warming of the inhaled air.

Larynx(larynx) performs the functions of breathing, voice formation and protection of the lower respiratory tract from foreign particles entering them. It occupies a middle position in the anterior region of the neck, forms a barely noticeable (in women) or strongly protruding forward (in men) elevation - a protrusion of the larynx (Fig. 4.3). Behind the larynx is the laryngeal part of the pharynx. The close connection of these organs is explained by the development of the respiratory system from the ventral wall of the pharyngeal intestine. In the pharynx there is a crossroads of the digestive and respiratory tracts.

larynx cavity can be divided into three sections: the vestibule of the larynx, the interventricular section and the subvocal cavity (Fig. 4.4).

Throat vestibule extends from the entrance to the larynx to the folds of the vestibule. The anterior wall of the vestibule (its height is 4 cm) is formed by a mucous membrane-covered epiglottis, and the posterior (1.0–1.5 cm in height) is formed by arytenoid cartilages.

Rice. 4.3. Larynx and thyroid gland.

Rice. 4.4. The cavity of the larynx on the sagittal section.

Interventricular department- the narrowest, extending from the folds of the vestibule above to the vocal folds below. Between the fold of the vestibule (false vocal fold) and the vocal fold on each side of the larynx is the ventricle of the larynx . The right and left vocal folds limit the glottis, which is the narrowest part of the larynx cavity. The length of the glottis (anteroposterior size) in men reaches 20-24 mm, in women - 16-19 mm. The width of the glottis during quiet breathing is 5 mm, during voice formation it reaches 15 mm. With the maximum expansion of the glottis (singing, screaming), tracheal rings are visible up to its division into the main bronchi.

lower division laryngeal cavity located under the glottis subvocal cavity, gradually expands and continues into the tracheal cavity. The mucous membrane lining the cavity of the larynx is pink color, covered with ciliated epithelium, contains many serous-mucous glands, especially in the region of the folds of the vestibule and ventricles of the larynx; glandular secretion moisturizes the vocal folds. In the region of the vocal folds, the mucous membrane is covered with a multilayer squamous epithelium, tightly grows together with the submucosa and does not contain glands.

Cartilages of the larynx. The skeleton of the larynx is formed by paired (arytenoid, corniculate and wedge-shaped) and unpaired (thyroid, cricoid and epiglottis) cartilages.

Thyroid cartilage – hyaline, unpaired, the largest of the cartilages of the larynx, consists of two quadrangular plates connected to each other in front at an angle of 90 o (in men) and 120 o (in women) (Fig. 4.5). In front of the cartilage there is an upper thyroid notch and a weakly expressed inferior thyroid notch. The posterior edges of the plates of the thyroid cartilage form a longer upper horn on each side and a short lower horn.

Rice. 4.5. Thyroid cartilage. A - front view; B - rear view. B - top view (with cricoid cartilage).

Cricoid cartilage- hyaline, unpaired, shaped like a ring, consists of an arc and a quadrangular plate. On the upper edge of the plate at the corners there are two articular surfaces for articulation with the right and left arytenoid cartilages. At the point of transition of the cricoid cartilage arc into its plate, on each side there is an articular platform for connection with lower horn thyroid cartilage.

arytenoid cartilage – hyaline, paired, similar in shape to a trihedral pyramid. The vocal process protrudes from the base of the arytenoid cartilage, formed by elastic cartilage to which the vocal cord is attached. Laterally from the base of the arytenoid cartilage, its muscular process departs for muscle attachment.

At the apex of the arytenoid cartilage in the thickness back section aryepiglottic fold lies corniculate cartilage. This is a paired elastic cartilage that forms a horn-shaped tubercle protruding above the top of the arytenoid cartilage.

sphenoid cartilage – paired, elastic. The cartilage is located in the thickness of the scoop-epiglottic fold, where it forms a wedge-shaped tubercle protruding above it. .

Epiglottis is based on epiglottic cartilage - unpaired, elastic in structure, leaf-shaped, flexible. The epiglottis is located above the entrance to the larynx, covering it from the front. The narrower lower end is the stalk of the epiglottis , attached to the inner surface of the thyroid cartilage.

Cartilage joints of the larynx. The cartilages of the larynx are connected to each other, as well as to the hyoid bone with the help of joints and ligaments. The mobility of the cartilage of the larynx is ensured by the presence of two paired joints and the action of the corresponding muscles on them (Fig. 4.6).

Rice. 4.6. Joints and ligaments of the larynx. Front view (A) and rear view (B)

cricothyroid joint- This is a paired, combined joint. Movement is carried out around the frontal axis passing through the middle of the joint. Leaning forward increases the distance between the angle of the thyroid cartilage and the arytenoid cartilages.

cricoarytenoid joint- paired, formed by a concave articular surface on the basis of the arytenoid cartilage and a convex articular surface on the plate of the cricoid cartilage. Movement in the joint occurs around vertical axis. With the rotation of the right and left arytenoid cartilages inward (under the action of the corresponding muscles), the vocal processes, together with the vocal cords attached to them, approach (the glottis narrows), and when rotated outward, they are removed, diverge to the sides (the glottis expands). In the cricoarytenoid joint, sliding is also possible, in which the arytenoid cartilages either move away from each other or approach each other. When the arytenoid cartilages slide, approaching each other, the posterior intercartilaginous part of the glottis narrows.

Along with the joints, the cartilages of the larynx are connected to each other, as well as to the hyoid bone by means of ligaments ( continuous connections). Between the hyoid bone and the upper edge of the thyroid cartilage, the median shield-hyoid ligament is stretched. Along the edges, the lateral shield-hyoid ligaments can be distinguished. The anterior surface of the epiglottis is attached to the hyoid bone by the hyoid-epiglottic ligament, and to the thyroid cartilage by the thyroid-epiglottic ligament.

Muscles of the larynx. All muscles of the larynx can be divided into three groups: dilators of the glottis (posterior and lateral cricoarytenoid muscles, etc.), constrictors (thyroid-arytenoid, anterior and oblique arytenoid muscles, etc.) and muscles that stretch (strain) the vocal cords (crico-thyroid and vocal muscles).

Trachea ( trachea) is an unpaired organ that serves to pass air into and out of the lungs. It starts from the lower border of the larynx at the level of the lower edge of the VI cervical vertebra and ends at the level of the upper edge of the V thoracic vertebra, where it divides into two main bronchi. This place is called bifurcation of the trachea (Fig. 4.7).

The trachea is in the form of a tube 9 to 11 cm long, somewhat compressed from front to back. The trachea is located in the neck area - the cervical part , and in the chest cavity thoracic part. AT cervical region the thyroid gland is attached to the trachea. Behind the trachea is the esophagus, and on the sides of it are the right and left neurovascular bundles (common carotid artery, internal jugular vein and vagus nerve). In the chest cavity in front of the trachea are the aortic arch, brachiocephalic trunk, left brachiocephalic vein, the beginning of the left common carotid artery and thymus (thymus).

To the right and left of the trachea is the right and left mediastinal pleura. The wall of the trachea consists of a mucous membrane, submucosa, fibrous-muscular-cartilaginous and connective tissue membranes. The basis of the trachea are 16–20 cartilaginous hyaline semirings, occupying about two thirds of the circumference of the trachea, with the open part facing backwards. Thanks to the cartilaginous half-rings, the trachea has flexibility and elasticity. Neighboring cartilages of the trachea are interconnected by fibrous annular ligaments.

Rice. 4.7. Trachea and bronchi. Front view.

main bronchi ( bronchi principales)(right and left) depart from the trachea at the level of the upper edge of the V thoracic vertebra and go to the gate of the corresponding lung. The right main bronchus has a more vertical direction, it is shorter and wider than the left one, and serves (in direction) as if a continuation of the trachea. Therefore, foreign bodies get into the right main bronchus more often than into the left one.

The length of the right bronchus (from the beginning to branching into the lobar bronchi) is about 3 cm, the left - 4-5 cm. Above the left main bronchus lies the aortic arch, above the right - the unpaired vein before it flows into the superior vena cava. The wall of the main bronchi in its structure resembles the wall of the trachea. Their skeleton is cartilaginous half-rings (in the right bronchus 6-8, in the left 9-12), behind the main bronchi have a membranous wall. From the inside, the main bronchi are lined with a mucous membrane, outside they are covered with a connective tissue membrane (adventitia).

Lung (rito). The right and left lungs are located in the chest cavity, in its right and left halves, each in its own pleural sac. Lungs located in pleural sacs, separated from each other mediastinum which contains the heart, large vessels(aorta, superior vena cava), esophagus and other organs. Below the lungs are adjacent to the diaphragm, in front, side and back, each lung is in contact with the chest wall. The left lung is narrower and longer, here part of the left half of the chest cavity is occupied by the heart, which is turned to the left with its apex (Fig. 4.8).

Rice. 4.8. Lungs. Front view.

The lung has the shape of an irregular cone with a flattened one side (facing the mediastinum). With the help of slits deeply protruding into it, it is divided into lobes, of which the right has three (upper, middle and lower), the left has two (upper and lower).

On the medial surface of each lung, slightly above its middle, there is an oval depression - the gate of the lung, through which the main bronchus, pulmonary artery, nerves enter the lung, and the pulmonary veins exit, lymphatic vessels. These formations make up the root of the lung.

At the gates of the lung, the main bronchus splits into lobar bronchi, of which there are three in the right lung, and two in the left, which are also divided into two or three segmental bronchi each. The segmental bronchus is included in the segment, which is a section of the lung, the base facing the surface of the organ, and the apex - to the root. The pulmonary segment consists of pulmonary lobules. The segmental bronchus and segmental artery are located in the center of the segment, and the segmental vein is located on the border with the neighboring segment. Segments are separated from each other connective tissue(small vascular zone). The segmental bronchus is divided into branches, of which there are approximately 9–10 orders (Fig. 4.9, 4.10).

Rice. 4.9. Right lung. Medial (inner) surface. 1-apex of the lung: 2-furrow subclavian artery; 3-pressure of the unpaired vein; 4-broncho-pulmonary The lymph nodes; 5-right main bronchus; 6-right pulmonary artery; 7-furrow - unpaired vein; 8-posterior edge of the lung; 9-pulmonary veins; 10-pi-aqueous impression; 11-pulmonary ligament; 12- depression of the inferior vena cava; 13-diaphragmatic surface (lower lobe of the lung); 14-lower edge of the lung; 15-middle lobe of the lung:. 16-heart depression; 17-oblique slot; 18-front edge of the lung; 19-upper lobe of the lung; 20-visceral pleura (cut off): 21-sulcus of the right and leuchocephalic vein

Rice. 4.10. Left lung. Medial (inner) surface. 1-apex of the lung, 2-groove of the left subclavian artery, 2-groove of the left brachiocephalic vein; 4-left pulmonary artery, 5-left main bronchus, 6-anterior edge of the left lung, 7-lung veins (left), 8-upper lobe of the left lung, 9-cardiac depression, 10-cardiac notch of the left lung, 11- oblique fissure, 12-uvula of the left lung, 13-inferior edge of the left lung, 14-diaphragmatic surface, 15-lower lobe of the left lung, 16-pulmonary ligament, 17-broncho-pulmonary lymph nodes, 18-aortic groove, 19-visceral pleura (cut off), 20-oblique slit.

A bronchus with a diameter of about 1 mm, still containing cartilage in its walls, enters a lung lobule called a lobular bronchus. Inside the pulmonary lobule, this bronchus divides into 18–20 terminal bronchioles. , of which there are about 20,000 in both lungs. The walls of the terminal bronchioles do not contain cartilage. Each terminal bronchiole is divided dichotomously into respiratory bronchioles, which have pulmonary alveoli on their walls.

From each respiratory bronchiole, alveolar passages depart, bearing the alveoli and ending in the alveolar and sacs. The bronchi of various orders, starting from the main bronchus, which serve to conduct air during breathing, make up the bronchial tree (Fig. 4.11). Respiratory bronchioles extending from the terminal bronchioles, as well as alveolar ducts, alveolar sacs and alveoli of the lung form the alveolar tree (pulmonary acinus). The alveolar tree, in which gas exchange between air and blood occurs, is a structural and functional unit of the lung. The number of pulmonary acini in one lung reaches 150,000, the number of alveoli is approximately 300–350 million, and the respiratory surface area of ​​all alveoli is about 80 m 2 ..

Rice. 4.11. Branching of the bronchi in the lung (scheme).

Pleura (pleura) - the serous membrane of the lung, is divided into visceral (pulmonary) and parietal (parietal). Each lung is covered with a pleura (pulmonary), which, along the surface of the root, passes into the parietal pleura, which lines the walls of the chest cavity adjacent to the lung and delimits the lung from the mediastinum. Visceral (lung) pleura densely fuses with the tissue of the organ and, covering it from all sides, enters the gaps between the lobes of the lung. Down from the lung root, the visceral pleura, descending from the anterior and posterior surfaces of the lung root, forms a vertically located lung ligament, llgr. pulmonale, lying in the frontal plane between the medial surface of the lung and the mediastinal pleura and descending almost to the diaphragm. Parietal (parietal) pleura is a continuous sheet that fuses with the inner surface chest wall and in each half of the chest cavity forms a closed bag containing the right or left lung, covered visceral pleura. Based on the position of the parts of the parietal pleura, the costal, mediastinal and diaphragmatic pleura are distinguished in it.

RESPIRATORY CYCLE consists of inhalation, exit and respiratory pause. The duration of inhalation (0.9-4.7 s) and exhalation (1.2-6 s) depends on reflex influences from the lung tissue. The frequency and rhythm of breathing is determined by the number of excursions chest per minute. At rest, an adult makes 16-18 breaths per minute.

Table 4.1. The content of oxygen and carbon dioxide in the inhaled and exhaled air

Rice. 4.12. The exchange of gases between the blood and air of the alveoli: 1 - the lumen of the alveoli; 2 - wall of the alveoli; 3 - wall blood capillary; 4 – capillary lumen; 5 - erythrocyte in the lumen of the capillary. The arrows show the path of oxygen, carbon dioxide through the air-blood barrier (between blood and air).

Table 4.2. Respiratory volumes.

MEDIASTINUM (mediastinum) is a complex of organs located between the right and left pleural cavities. The mediastinum is bounded anteriorly by the sternum, posteriorly by the thoracic region spinal column, from the sides - by the right and left mediastitial pleura. Currently, the mediastinum is conditionally divided into the following:

The human respiratory system is a collection of organs necessary for proper breathing and gas exchange. It included the upper respiratory tract and the lower ones, between which there is a conditional boundary. The respiratory system functions 24 hours a day, increasing its activity during motor activity, physical or emotional stress.

Appointment of organs included in the upper respiratory tract

The upper respiratory tract includes several important organs:

1. Nose, nasal cavity.
2. Throat.
3. Larynx.

The upper respiratory system is the first to take part in the processing of inhaled air currents. It is here that the initial purification and warming of the incoming air is carried out. Then there is its further transition to the lower paths to participate in important processes.

Nose and nasal cavity

The human nose consists of a bone that forms its back, lateral wings and a tip based on flexible septal cartilage. The nasal cavity is represented by an air channel that communicates with the external environment through the nostrils, and is connected behind the nasopharynx. This section consists of bone, cartilage tissue separated from the oral cavity by the hard and soft palate. The inside of the nasal cavity is covered with a mucous membrane.

Proper functioning of the nose ensures:

• purification of the inhaled air from foreign inclusions;
• neutralization pathogenic microorganisms(this is due to the presence of a special substance in the nasal mucus - lysozyme);
• humidification and warming of the air flow.

In addition to breathing, this area of ​​​​the upper respiratory tract performs an olfactory function, and is responsible for the perception of various aromas. This process occurs due to the presence of a special olfactory epithelium.

An important function of the nasal cavity is an auxiliary role in the process of voice resonation.

Nasal breathing provides disinfection and warming of the air. In the process of breathing through the mouth, such processes are absent, which, in turn, leads to the development bronchopulmonary pathologies(mainly in children).

Functions of the pharynx

The pharynx is the back of the throat into which the nasal cavity passes. It looks like a funnel-shaped tube 12-14 cm long. The pharynx is formed by 2 types of tissue - muscular and fibrous. From the inside, it also has a mucous membrane.

The pharynx consists of 3 sections:

1. Nasopharynx.
2. Oropharynx.
3. hypopharynx.

The function of the nasopharynx is to ensure the movement of air that is inhaled through the nose. This department has a message with the ear canals. It contains adenoids, consisting of lymphoid tissue, which take part in filtering the air from harmful particles, maintaining immunity.

The oropharynx serves as a pathway for air to pass through the mouth in case of breathing. This section of the upper respiratory tract is also intended for eating. The oropharynx contains the tonsils, which, together with the adenoids, support the protective function of the body.

Food masses pass through the laryngopharynx, entering further into the esophagus and stomach. This part of the pharynx begins in the region of 4-5 vertebrae, and gradually passes into the esophagus.

What is the importance of the larynx

The larynx is an organ of the upper respiratory tract involved in the processes of respiration and voice formation. It is arranged like a short tube, occupies a position opposite 4-6 cervical vertebrae.

The anterior part of the larynx is formed by the hyoid muscles. In the upper region is the hyoid bone. Laterally, the larynx borders on the thyroid gland. The skeleton of this organ consists of unpaired and paired cartilages connected by joints, ligaments and muscles.

The human larynx is divided into 3 sections:

1. Upper, called the vestibule. This area is stretched from the vestibular folds to the epiglottis. Within its limits there are folds of the mucous membrane, between them there is a vestibular fissure.
2. The middle (interventricular section), the narrowest part of which, the glottis, consists of intercartilaginous and membranous tissue.
3. Lower (sub-vocal), occupying the area under the glottis. expanding this department passes into the trachea.

The larynx consists of several membranes - mucous, fibrocartilaginous and connective tissue, connecting it with other cervical structures.

This body has 3 main functions:

• respiratory - contracting and expanding, the glottis contributes to right direction inhaled air;
• protective - the mucous membrane of the larynx includes nerve endings that cause a protective cough when food is not properly ingested;
• voice-forming - the timbre and other characteristics of the voice are determined by the individual anatomical structure, the state of the vocal cords.

The larynx is considered an important organ responsible for the production of speech.

Some disorders in the functioning of the larynx can pose a threat to health and even human life. These phenomena include laryngospasm - a sharp contraction of the muscles of this organ, leading to complete closure of the glottis and the development of inspiratory dyspnea.

The principle of the device and operation of the lower respiratory tract

The lower respiratory tract includes the trachea, bronchi, and lungs. These organs form the final section of the respiratory system, serve to transport air and carry out gas exchange.

Trachea

The trachea (windpipe) is an important part of the lower respiratory tract that connects the larynx to the bronchi. This organ is formed by arcuate tracheal cartilages, the number of which in different people is from 16 to 20 pcs. The length of the trachea is also not the same, and can reach 9-15 cm. The place where this organ begins is at the level of the 6th cervical vertebra, near the cricoid cartilage.

The windpipe includes glands, the secret of which is necessary for the destruction of harmful microorganisms. In the lower part of the trachea, in the region of the 5th vertebra of the sternum, it is divided into 2 bronchi.

In the structure of the trachea, 4 different layers are found:

1. The mucous membrane is in the form of a stratified ciliated epithelium lying on the basement membrane. It consists of stem, goblet cells that secrete a small amount of mucus, as well as cell structures producing norepinephrine and serotonin.
2. Submucosal layer, which looks like loose connective tissue. It contains many small vessels and nerve fibers responsible for blood supply and regulation.
3. The cartilaginous part, which contains hyaline cartilages connected to each other by means of ring ligaments. Behind them is a membrane connected to the esophagus (due to its presence, the respiratory process is not disturbed during the passage of food).
4. The adventitia is a thin connective tissue that covers outer part tubes.

The main function of the trachea is to carry air to both lungs. The windpipe also performs a protective role - if foreign small structures enter it together with air, they are enveloped in mucus. Further, with the help of cilia, foreign bodies are pushed into the region of the larynx, and enter the pharynx.

The larynx partially provides warming of the inhaled air, and also participates in the process of voice formation (by pushing air flows to the vocal cords).

How are bronchi arranged?

The bronchi are a continuation of the trachea. The right bronchus is considered the main one. It is located more vertically, in comparison with the left has big sizes and thickness. The structure of this organ consists of arcuate cartilage.

The area where the main bronchi enter the lungs is called the "gate". Further, they branch into smaller structures - bronchioles (in turn, they pass into alveoli - the smallest spherical sacs surrounded by vessels). All "branches" of the bronchi, having different diameters, are combined under the term "bronchial tree".

The walls of the bronchi are composed of several layers:

• external (adventitious), including connective tissue;
• fibrocartilaginous;
• submucosal, which is based on loose fibrous tissue.

The inner layer is mucous, includes muscles and cylindrical epithelium.

The bronchi perform essential functions in the body:

1. Deliver air masses to the lungs.
2. Purify, humidify and warm the air inhaled by a person.
3. Support the functioning of the immune system.

This organ largely ensures the formation of a cough reflex, due to which small foreign bodies, dust and harmful microbes are removed from the body.

The final organ of the respiratory system is the lungs.

A distinctive feature of the structure of the lungs is the pair principle. Each lung includes several lobes, the number of which varies (3 in the right and 2 in the left). In addition, they have various shape and size. So, the right lung is wider and shorter, while the left, closely adjacent to the heart, is narrower and elongated.

The paired organ completes the respiratory system, densely penetrated by the "branches" of the bronchial tree. In the alveoli of the lungs, vital gas exchange processes are carried out. Their essence lies in the processing of oxygen entering during inhalation into carbon dioxide, which is excreted into the external environment with exhalation.

In addition to providing breathing, the lungs perform other important functions in the body:

• support within allowable rate acid-base balance;
• take part in the removal of alcohol vapors, various toxins, ethers;
• participate in the elimination of excess fluid, evaporate up to 0.5 liters of water per day;
• help complete blood clotting (coagulation);
• involved in the functioning of the immune system.

Doctors state - with age functionality upper and lower respiratory tract are limited. The gradual aging of the body leads to a decrease in the level of lung ventilation, a decrease in the depth of breathing. The shape of the chest, the degree of its mobility also changes.

To avoid early weakening of the respiratory system and to prolong it as much as possible full functions, it is recommended to give up smoking, alcohol abuse, a sedentary lifestyle, to carry out timely, high-quality treatment of infectious and viral diseases affecting the upper and lower respiratory tract.

What can be called the main indicator of human viability? Of course, we are talking about breathing. A person can go without food and water for a while. Without air, life is not possible at all.

General information

What is breath? It is the link between the environment and people. If the intake of air is difficult for any reason, then the heart and respiratory organs of a person begin to function in an enhanced mode. This is due to the need to ensure enough oxygen. Organs are able to adapt to changing environmental conditions.

Scientists were able to establish that the air entering the human respiratory system forms two streams (conditionally). One of them penetrates left side nose. The study of the respiratory organs shows that the second passes with right side. Experts also proved that the arteries of the brain are divided into two streams of receiving air. Thus, the breathing process must be correct. This is very important for maintaining the normal life of people. Consider the structure of the human respiratory system.

Important Features

When talking about respiration, we are talking about a set of processes that are aimed at ensuring a continuous supply of all tissues and organs with oxygen. At the same time, substances that are formed during the exchange of carbon dioxide are removed from the body. Breathing is a very complex process. It goes through several stages. The stages of air entry and exit into the body are as follows:

1. We are talking about gas exchange between atmospheric air and the alveoli. This stage is considered external breathing.
2. The exchange of gases carried out in the lungs. It occurs between the blood and alveolar air.
3. Two processes: the delivery of oxygen from the lungs to the tissues, as well as the transport of carbon dioxide from the latter to the former. That is, we are talking about the movement of gases with the help of blood flow.
4. The next stage of gas exchange. It involves tissue cells and capillary blood.
5. Finally, inner breathing. This refers to what occurs in the mitochondria of cells.

Main goals

The human respiratory system removes carbon dioxide from the blood. Their task also includes its saturation with oxygen. If you list the functions of the respiratory system, then this is the most important.

Additional appointment

There are other functions of the human respiratory organs, among them are the following:

1. Taking part in the processes of thermoregulation. The fact is that the temperature of the inhaled air affects a similar parameter of the human body. During exhalation, the body releases heat to the environment. At the same time, it is cooled, if possible.
2. Taking part in excretory processes. During exhalation, along with air from the body (except carbon dioxide), water vapor is eliminated. This also applies to some other substances. For example, ethyl alcohol while intoxicated.
3. Taking part in immune responses. Thanks to this function of the human respiratory organs, it becomes possible to neutralize some pathologically dangerous elements. These include, in particular, pathogenic viruses, bacteria and other microorganisms. This ability is endowed with certain cells of the lungs. In this regard, they can be attributed to the elements of the immune system.

Specific tasks

There are very narrowly focused functions of the respiratory organs. In particular, specific tasks are performed by the bronchi, trachea, larynx, and nasopharynx. Among these narrowly focused functions, the following can be distinguished:

1. Cooling and heating of incoming air. This task is carried out according to the ambient temperature.
2. Humidification of the air (inhaled), which prevents the lungs from drying out.
3. Purification of incoming air. In particular, this applies to foreign particles. For example, to dust entering with air.

The structure of the human respiratory system

All elements are connected by special channels. Air enters and exits through them. Also included in this system are the lungs - organs where gas exchange occurs. The device of the whole complex and the principle of its operation are quite complex. Consider the human respiratory organs (pictures are presented below) in more detail.

Information about the nasal cavity

The airways begin with her. The nasal cavity is separated from the oral cavity. The front is the hard palate, and the back is the soft palate. The nasal cavity has a cartilaginous and bony framework. It is divided into left and right parts thanks to a solid partition. Three turbinates are also present. Thanks to them, the cavity is divided into passages:

1. Lower.
2. Average.
3. Upper.

They carry exhaled and inhaled air.

Features of the mucosa

She has a number of devices that are designed to process the inhaled air. First of all, it is covered with ciliated epithelium. Its cilia form a continuous carpet. Due to the fact that the cilia flicker, dust is easily removed from the nasal cavity. The hairs that are located at the outer edge of the holes also contribute to the retention of foreign elements. contains special glands. Their secret envelops the dust and helps to eliminate it. In addition, the air is humidified.

The mucus that is in the nasal cavity has bactericidal properties. It contains lysozyme. This substance helps to reduce the ability of bacteria to reproduce. It also kills them. In the mucous membrane there are many venous vessels. At various conditions they can swell. If they are damaged, then nosebleeds begin. The purpose of these formations is to heat the air stream passing through the nose. Leukocytes leave the blood vessels and end up on the surface of the mucosa. They also perform protective functions. In the process of phagocytosis, leukocytes die. Thus, in the mucus that is discharged from the nose, there are many dead "protectors". Then the air passes into the nasopharynx, and from there - to other organs of the respiratory system.

Larynx

It is located in the anterior laryngeal part of the pharynx. This is the level of the 4th-6th cervical vertebrae. The larynx is formed by cartilage. The latter are divided into paired (wedge-shaped, corniculate, arytenoid) and unpaired (cricoid, thyroid). In this case, the epiglottis is attached to top edge last cartilage. During swallowing, it closes the entrance to the larynx. Thus, it prevents food from getting into it.

General information about the trachea

It is a continuation of the larynx. It is divided into two bronchi: left and right. The bifurcation is where the trachea branches. It is characterized by the following length: 9-12 centimeters. On average, the transverse diameter reaches eighteen millimeters.

The trachea may include up to twenty incomplete cartilaginous rings. They are connected by fibrous ligaments. Thanks to the cartilaginous half-rings, the airways become elastic. In addition, they are made falling, therefore, they are easily passable for air.

The membranous posterior wall of the trachea is flattened. It contains smooth muscle tissue (bundles that run longitudinally and transversely). This ensures active movement trachea when coughing, breathing, and so on. As for the mucous membrane, it is covered with ciliated epithelium. In this case, the exception is part of the epiglottis and vocal cords. It also has mucous glands and lymphoid tissue.

Bronchi

This is a pair element. The two bronchi into which the trachea divides enter the left and right lungs. There they branch in a tree-like manner into smaller elements, which are included in the lung lobules. Thus, bronchioles are formed. We are talking about even smaller respiratory branches. The diameter of the respiratory bronchioles can be 0.5 mm. They, in turn, form the alveolar passages. The latter end with matching pouches.

What are alveoli? These are protrusions that look like bubbles, which are located on the walls of the corresponding sacs and passages. Their diameter reaches 0.3 mm, and the number can reach up to 400 million. This makes it possible to create a large respiratory surface. This factor significant effect on lung capacity. The latter can be increased.

The most important human respiratory organs

They are considered lungs. Serious diseases associated with them can be life threatening. The lungs (photos are presented in the article) are located in the chest cavity, which is hermetically sealed. Its back wall is formed by the corresponding section of the spine and ribs, which are movably attached. Between them are the internal and external muscles.

The chest cavity is separated from the abdominal cavity from below. This involves the abdominal obstruction, or diaphragm. The anatomy of the lungs is not simple. A person has two. The right lung has three lobes. At the same time, the left one consists of two. The apex of the lungs is their narrowed upper part, and the expanded lower part is considered the base. The gates are different. They are represented by depressions on the inner surface of the lungs. Through them pass blood nerves, as well as lymphatic vessels. The root is represented by a combination of the above formations.

The lungs (the photo illustrates their location), or rather their tissue, consist of small structures. They are called slices. We are talking about small areas that have a pyramidal shape. The bronchi that enter the corresponding lobule are subdivided into respiratory bronchioles. There is an alveolar passage at the end of each of them. This whole system is a functional unit of the lungs. It's called an acinus.

The lungs are covered with pleura. It is a shell consisting of two elements. We are talking about the outer (parietal) and inner (visceral) petals (the scheme of the lungs is attached below). The latter covers them and at the same time is the outer shell. It makes a transition to the outer layer of the pleura along the root and is the inner shell of the walls of the chest cavity. This leads to the formation of a geometrically closed smallest capillary space. We are talking about the pleural cavity. It contains a small amount of the corresponding liquid. She wets the leaves of the pleura. This makes it easier for them to slide between each other. Change of air in the lungs occurs for many reasons. One of the main ones is a change in the size of the pleural and chest cavities. This is the anatomy of the lungs.

Features of the air inlet and outlet mechanism

As mentioned earlier, there is an exchange between the gas that is in the alveoli and the atmospheric one. This is due to the rhythmic alternation of inhalations and exhalations. The lungs do not have muscle tissue. For this reason, their intensive reduction is impossible. In this case, the most active role is given to the respiratory muscles. With their paralysis, it is not possible to take a breath. In this case, the respiratory organs are not affected.

Inspiration is the act of inhaling. This is an active process, during which an increase in the chest is provided. Expiration is the act of exhaling. This process is passive. It occurs due to the fact that the chest cavity decreases.

The respiratory cycle is represented by the phases of inhalation and subsequent exhalation. The diaphragm and external oblique muscles take part in the process of air entry. When they contract, the ribs begin to rise. At the same time, there is an increase in the chest cavity. The diaphragm contracts. At the same time, it occupies a more flat position.

As for incompressible organs, in the course of the process under consideration, they are pushed aside and down. The dome of the diaphragm with a calm breath drops by about one and a half centimeters. Thus, there is an increase vertical dimension chest cavity. In case of very deep breathing Auxiliary muscles take part in the act of inhalation, among which the following stand out:

1. Diamond-shaped (which raise the shoulder blade).
2. Trapezoidal.
3. Small and large chest.
4. Anterior gear.

The serosa covers the wall of the chest cavity and lungs. The pleural cavity is represented by a narrow gap between the sheets. It contains serous fluid. The lungs are always in a stretched state. This is due to the fact that the pressure in the pleural cavity is negative. It's about elasticity. The fact is that the volume of the lungs constantly tends to decrease. At the end of a quiet expiration, almost every respiratory muscle relaxes. In this case, the pressure in the pleural cavity is below atmospheric pressure. In different people leading role in the act of inhalation, the diaphragm or intercostal muscles play. Accordingly, one can speak of different types breathing:

1. Ribburn.
2. Diaphragmatic.
3. Abdomen.
4. Chest.

It is now known that the latter type of breathing predominates in women. In men, in most cases, abdominal pain is observed. During quiet breathing, exhalation occurs due to elastic energy. It accumulates during the previous breath. When the muscles relax, the ribs can passively return to their original position. If the contractions of the diaphragm decrease, then it will return to its previous domed position. This is due to the fact that the abdominal organs act on it. Thus, the pressure in it decreases.

All of the above processes lead to compression of the lungs. Air comes out of them (passive). Forced exhalation is an active process. It involves the internal intercostal muscles. At the same time, their fibers go in the opposite direction, if compared with the outer ones. They contract and the ribs drop down. There is also a reduction in the chest cavity.

The respiratory system performs the function of gas exchange, delivering oxygen to the body and removing carbon dioxide from it. The airways are the nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles and lungs.

In the upper respiratory tract, the air is warmed, cleaned of various particles and humidified. Gas exchange takes place in the alveoli of the lungs.

nasal cavity It is lined with a mucous membrane, in which two parts differ in structure and function: respiratory and olfactory.

The respiratory part is covered with ciliated epithelium that secretes mucus. Mucus moisturizes the inhaled air, envelops solid particles. The mucous membrane warms the air, as it is abundantly supplied with blood vessels. Three turbinates increase the overall surface of the nasal cavity. Under the shells are the lower, middle and upper nasal passages.

Air from the nasal passages enters through the choanae into the nasal, and then into the oral part of the pharynx and larynx.

Larynx performs two functions - respiratory and voice formation. The complexity of its structure is associated with the formation of voice. The larynx is located at the level of the IV-VI cervical vertebrae and is connected by ligaments to the hyoid bone. The larynx is formed by cartilage. Outside (in men this is especially noticeable) the "Adam's apple" protrudes, " adam's apple"- thyroid cartilage. At the base of the larynx is the cricoid cartilage, which is connected by joints to the thyroid and two arytenoid cartilages. The cartilaginous vocal process departs from the arytenoid cartilages. The entrance to the larynx is covered by an elastic cartilaginous epiglottis attached to the thyroid cartilage and hyoid bone by ligaments.

Between the arytenoids and the inner surface of the thyroid cartilage are vocal cords, consisting of elastic fibers of connective tissue. Sound is produced by the vibration of the vocal cords. The larynx takes part only in the formation of sound. Lips, tongue, soft palate, paranasal sinuses take part in articulate speech. The larynx changes with age. Its growth and function are associated with the development of the gonads. The size of the larynx in boys during puberty increases. The voice changes (mutates).

Air enters the trachea from the larynx.

Trachea- a tube, 10-11 cm long, consisting of 16-20 cartilaginous rings not closed behind. The rings are connected by ligaments. The posterior wall of the trachea is formed by dense fibrous connective tissue. The food bolus passing through the esophagus, adjacent to the posterior wall of the trachea, does not experience resistance from it.

The trachea divides into two elastic main bronchi. The right bronchus is shorter and wider than the left. The main bronchi branch into smaller bronchi - bronchioles. The bronchi and bronchioles are lined with ciliated epithelium. The bronchioles contain secretory cells that produce enzymes that break down surfactant, a secret that helps maintain the surface tension of the alveoli, preventing them from collapsing when exhaled. It also has a bactericidal effect.

Lungs, paired organs located in the chest cavity. The right lung has three lobes, the left has two. The lobes of the lung, to a certain extent, are anatomically isolated areas with a bronchus that ventilates them and their own vessels and nerves.

The functional unit of the lung is the acinus, a branching system of one terminal bronchiole. This bronchiole is divided into 14-16 respiratory bronchioles, forming up to 1500 alveolar passages, bearing up to 20,000 alveoli. The pulmonary lobule consists of 16-18 acini. Segments are made up of lobules, lobes are made up of segments, and a lung is made up of lobes.

Outside, the lung is covered with an internal pleura. Its outer layer (parietal pleura) lines the chest cavity and forms a sac in which the lung is located. Between the outer and inner sheets is the pleural cavity, filled with a small amount fluid that facilitates the movement of the lungs during breathing. The pressure in the pleural cavity is less than atmospheric and is about 751 mm Hg. Art.

When inhaling, the chest cavity expands, the diaphragm descends, and the lungs expand. When exhaling, the volume of the chest cavity decreases, the diaphragm relaxes and rises. The respiratory movements involve the external intercostal muscles, the muscles of the diaphragm, and the internal intercostal muscles. With increased breathing, all the muscles of the chest are involved, lifting the ribs and sternum, the muscles of the abdominal wall.

Tidal volume is the amount of air inhaled and exhaled by a person calm state. It is equal to 500 cm 3.

Extra volume - the amount of air that a person can inhale after a normal breath. This is another 1500 cm 3.

The reserve volume is the amount of air that a person can exhale after a normal exhalation. It is equal to 1500 cm 3. All three quantities make up the vital capacity of the lungs.

Residual air is the amount of air that remains in the lungs after the deepest exhalation. It is equal to 1000 cm 3.

Respiratory movements are controlled by the respiratory center medulla oblongata. The center has departments of inhalation and exhalation. From the center of inhalation, impulses are sent to the respiratory muscles. There is a breath. Impulses from the respiratory muscles are sent to respiratory center on vagus nerve and inhibit the inspiratory center. There is an exhalation. The activity of the respiratory center is affected by the level blood pressure, temperature, pain and other stimuli. Humoral regulation occurs when the concentration of carbon dioxide in the blood changes. Its increase excites the respiratory center and causes quickening and deepening of breathing. The ability to arbitrarily hold your breath for a while is explained by the controlling influence on the breathing process of the cerebral cortex.

Gas exchange in the lungs and tissues occurs by diffusion of gases from one medium to another. The partial pressure of oxygen in atmospheric air is higher than in alveolar air, and it diffuses into the alveoli. From the alveoli, for the same reasons, oxygen penetrates into venous blood, saturating it, and from the blood - into the tissue.

The partial pressure of carbon dioxide in the tissues is higher than in the blood, and in the alveolar air is higher than in atmospheric (). Therefore, it diffuses from the tissues into the blood, then into the alveoli and into the atmosphere.

General characteristics of the respiratory system

The most important indicator of human viability can be called breath. A person can do without water and food for some time, but life is impossible without air. Breathing is the link between a person and the environment. If the air flow is obstructed, then respiratory organs I am a person and the heart begins to work in an enhanced mode, which provides the necessary amount of oxygen for breathing. The human respiratory and respiratory system is capable of adapt to environmental conditions.

Scientists have established interesting fact. The air that enters respiratory system of a person, conditionally forms two streams, one of which passes into the left side of the nose and penetrates into left lung, the second flow penetrates into right side nose and submits to right lung.

Also, studies have shown that in the artery of the human brain there is also a separation into two streams of air received. Process breathing must be correct, which is important for normal life. Therefore, it is necessary to know about the structure of the human respiratory system and respiratory organs.

Breathe-helping machine human includes trachea, lungs, bronchi, lymphatics, and vascular system . They also include nervous system and respiratory muscles, pleura. The human respiratory system includes the upper and lower respiratory tract. Upper respiratory tract: nose, pharynx, oral cavity. Lower respiratory tract: trachea, larynx and bronchi.

The airways are necessary for the entry and removal of air from the lungs. Most main body the entire respiratory system lungs between which the heart is located.

Respiratory system

Lungs- the main organs of respiration. They are cone shaped. The lungs are located in the chest area, located on either side of the heart. The main function of the lungs is gas exchange, which occurs with the help of the alveoli. Blood from the veins enters the lungs through pulmonary arteries. Air penetrates through the respiratory tract, enriching the respiratory organs with the necessary oxygen. Cells need to be supplied with oxygen in order for the process to take place. regeneration, and acted nutrients from the blood necessary for the body. Covers the lungs - the pleura, consisting of two petals, separated by a cavity (pleural cavity).

The lungs include the bronchial tree, which is formed by bifurcation trachea. The bronchi, in turn, are divided into thinner ones, thus forming segmental bronchi. bronchial tree ends with very small pouches. These sacs are many interconnected alveoli. Alveoli provide gas exchange respiratory system. The bronchi are covered with epithelium, which in its structure resembles cilia. Cilia remove mucus to the pharyngeal region. Promotion is promoted by coughing. The bronchi have a mucous membrane.

Trachea is a tube that connects the larynx and bronchi. The trachea is about 12-15 see Trachea, in contrast to the lungs - an unpaired organ. The main function of the trachea is to carry air into and out of the lungs. The trachea is located between the sixth vertebra of the neck and the fifth vertebra of the thoracic region. In the end trachea bifurcates into two bronchi. The bifurcation of the trachea is called a bifurcation. At the beginning of the trachea, the thyroid gland adjoins it. On the back of the trachea is the esophagus. The trachea is covered by a mucous membrane, which is the basis, and it is also covered by muscular-cartilaginous tissue, a fibrous structure. The trachea is made up of 18-20 rings of cartilage, thanks to which the trachea is flexible.

Larynx- a respiratory organ that connects the trachea and pharynx. The voice box is located in the larynx. The larynx is in the area 4-6 vertebrae of the neck and with the help of ligaments attached to the hyoid bone. The beginning of the larynx is in the pharynx, and the end is a bifurcation into two tracheas. The thyroid, cricoid, and epiglottic cartilages make up the larynx. These are big unpaired cartilages. It is also formed by small paired cartilages: horn-shaped, wedge-shaped, arytenoid. The connection of the joints is provided by ligaments and joints. Between the cartilages are membranes that also perform the function of connection.

Pharynx is a tube that originates in the nasal cavity. The pharynx crosses the digestive and respiratory tracts. The pharynx can be called the link between the nasal cavity and the oral cavity, and the pharynx also connects the larynx and esophagus. The pharynx is located between the base of the skull and 5-7 neck vertebrae. The nasal cavity is initial department respiratory system. Consists of the external nose and nasal passages. The function of the nasal cavity is to filter the air, as well as to purify and moisten it. Oral cavity This is the second way air enters the human respiratory system. The oral cavity has two sections: posterior and anterior. The anterior section is also called the vestibule of the mouth.