Respiration is a set of processes that ensure the body's consumption of oxygen and the release of carbon dioxide.
The most important functions of the respiratory system are:
- Providing the body with oxygen and its use in redox processes
- Formation and excretion of excess from the body carbon dioxide
- Oxidation (decomposition) of organic compounds with the release of energy
- Isolation of volatile metabolic products (water vapor (500 ml per day), alcohol, ammonia, etc.)
Bodies performing the air-conducting function:
- Nose
- Nasal cavity
- Nasopharynx
- Larynx
- Trachea
- Bronchi
- Bronchioles
Organs that perform respiratory (respiratory) function:
- Lungs (alveolar passages and alveoli that form acinuses)
Subsidiary bodies:
- Chest
- Respiratory muscles
- Circulatory system
Nasal cavity
The initial department of the respiratory tract and at the same time the olfactory organ.
The nasal cavity extends from the nostrils to the pharynx and is divided by a septum into two halves, which in front through the nostrils connect with the atmosphere, and behind with the help of hoan - with the nasopharynx.
Larynx
The larynx is located at the level of IV-VI cervical vertebrae, below the hyoid bone with which it is connected by ligaments, forming a noticeable elevation (in men, "Adam's apple"), is an entrance that protects the lungs. The vocal cords are located in the larynx. Behind the larynx is the pharynx, with which it connects with its upper opening. Pharynx
- odd organ located in the head and neck, funnel-shaped tube, the intersection of the digestive and respiratory tracts. The pharynx opens the openings of the nasal cavity (hoana) and mouth (throat). From below the larynx passes into the trachea.
The vocal cords
The vocal cords are located in the thickness of the vocal folds, formed by elastic fibers, stretched between the thyroid and scoop cartilage and serve to reproduce sounds.
The trachea is a direct extension of the larynx.
It starts from the annular cartilage, at the level of the VI cervical vertebra, ends at the level of the IV-V thoracic.
At the level of the angle of the sternum, the trachea ends in a division into two main bronchi (bifurcation).
The length of the trachea is 8-12 cm,
transverse diameter 1.5-1.8 cm.
Tracheal tissue - strong, fibrous-elastic, the wall consists of 16-20 incomplete
cartilaginous semicircles of hyaline cartilage connected by ligaments. They extend in 2/3 of a circle, have a U-shape, are not closed behind and help keep the lumen of the trachea always open.
The posterior wall of the trachea (where the cartilaginous rings are not closed) is membranous, flat, consists of fibrous tissue and muscle fibers. This wall touches the esophagus, located directly behind the trachea. It bends inward when food passes through the esophagus.
Nerves, blood and lymphatic vessels, mucous glands pass in the connective tissue.
The inner surface is covered with ciliated epithelium (when oscillating discard small particles from the lungs up to the larynx). Cells secrete mucus.
The bronchi depart from the trachea almost at right angles and go to the gate of the lungs.
The right bronchus is wider, but shorter than the left and is an extension of the trachea.
ACINUS
The whole complex, starting with the respiratory bronchiole, looks like a bunch of grapes, so it is called ACINUS (acinus - bunch).
Acinus - a structural unit of the lungs (up to 300 thousand), which is the gas exchange between the blood in
capillaries of the lungs, and the air that fills the pulmonary alveoli.
The acinus includes 15-20 alveoli.
Alveoli (in the lungs of an adult 300 million, their total surface area of 140 m2)
- open bubbles with very thin
walls formed by a single layer of squamous epithelium.
Alveoli are surrounded by blood capillaries, which together with epitheliocytes form a barrier between blood and air (aerohematical barrier)
0.5 μm thick, which does not interfere with gas exchange and water vapor evolution.
Lungs
The right and left lungs are two separate objects located in the thoracic cavity on the sides of the heart; covered with a serous membrane - the pleura, which forms around them two closed pleural sacs.
They have an irregular conical shape with the base facing the diaphragm and the tip protruding 2-3 cm above the clavicle in the neck.
The lung consists of a system of airways - bronchi (bronchial tree) and pulmonary system
vesicles - alveoli, which act as respiratory departments of the respiratory system.
Each lung is freely located in the thoracic cavity, attached to the mediastinum by roots from the main bronchi and large blood vessels.
Lung tissue is soft, loose and elastic, has a pink color in childhood, but with age it becomes darker and covered with spots, as the lungs are filled with dust, which is captured by cells lining the airways.
There are three surfaces in the lungs:
- Rib - convex, adjacent to the inner surface of the chest wall;
- Diaphragmatic - adjacent to the diaphragm;
- Medial - internal, facing the mediastinal organs, located between the pleural sacs.
Segments of the right lung:
Upper lobe segments:
1. Apical segment
2. Posterior segment
3. Anterior segment
Middle share segments:
4. Lateral segment
5. Medial segment
Segments of the lower lobe:
6. Upper segment
7. Medial basal segment
8. Anterior basal segment
9. Lateral basal segment
10. Posterior basal segment
Segments of the left lung:
Upper lobe segments:
1. Apical segment
2. Posterior segment
3. Anterior segment
4. Upper lingual segment
5. Lower lingual segment
The segments of the lower lobe coincide with the right lungs.
6. Upper segment
7. The medial basal segment is not constant.
8. Anterior basal segment
9. Lateral basal segment
10. Posterior basal segment
The root of the right lung
The root of the lung (Latin radix pulmonis) is a complex of anatomical structures that pass through the gates of the lungs and connect the lungs with the mediastinum. These are the main bronchus, pulmonary artery and two veins, bronchial arteries, lymph vessels and nodes and nerve plexuses.
4 - Bronch
5 - Pulmonary artery
3 - Pulmonary veins
The root of the left lung
5 - Pulmonary artery
4 - Bronch
3 - Pulmonary veins
Pleura
The serous membrane of the lung is called the pleura. Covering the lung on all sides, it passes along the root of the lung to the walls of the thoracic cavity, forming a closed pleural sac around the lung. There are right and left pleural sacs.
Parietal, or parietal pleura - a leaf of the pleura, lining the walls of the thoracic cavity and fused with them. There are costal, diaphragmatic, and mediastinal (mediastinal) pleura.
Visceral, or pulmonary, pleura - the pleura that covers the lung and grows with its surface.
Between the parietal and visceral pleura is the pleural cavity - a capillary gap containing a small amount of fluid, which reduces friction between the two leaves of the pleura during respiratory movements. In places of transition of one part of a parietal pleura to another spare spaces - pockets, or sinuses are formed
pleura, which are filled with lungs at the time of maximum inspiration, and at rest, their walls are tightly pressed together. Especially large rib- diaphragmatic sinus, located in the lower pleural cavity.
The boundaries of the pleural sacs and lungs
To determine the position of the thoracic and abdominal cavities, several vertical lines are drawn.
The main ones are the middle clavicle (through the middle of the clavicle), the middle axillary (descends from
middle of the axilla (scapular), scapular (passes through the lower corner of the scapula) and Vertebral (on the heads
ribs).
* The boundaries of the pleura. The upper limit is 3-4 cm above the front end of the I rib. The back corresponds to the place of transition
costal pleura in the mediastinum and goes along the vertebral line to the XII rib. The leading edge is the most variable.
It corresponds to the anterior line of transition of the costal pleura to the mediastinum. At the top, the edges of the pleural sacs are symmetrical and extend from the upper point to the sternoclavicular joint, at the level of II-IV ribs of the border
pleural sacs converge and go vertically downward, being slightly shifted to the left. Starting with their IV ribs
the borders diverge downwards and laterally to the VII rib along the midclavicular line. The lower limit represents the line
transition of the costal pleura to the diaphragmatic. It intersects the midclavicular line VII rib, the middle axillary - IX, then goes horizontally, crossing the X and XI ribs, where it meets the posterior
border.
* The boundaries of the lungs. The position of the tips of the lungs and their posterior edges corresponds to the boundaries of the pleura. The front edge of the right
the lungs are located according to the anterior border of the pleura. The anterior border of the left lung coincides with the border of the pleura
only in the upper part to the level of the IV rib, where the edge of the lung, forming a cardiac notch, recedes to the left on the IV
rib to the midclavicular line and then goes vertically down to the VI rib. Hence, the lower border crosses the middle axillary line at the level of the VIII rib, the scapular - at the level of X and the vertebral - at the level of the XI rib, where it passes into the posterior border. The boundary between the upper and lower lobes of the lung passes posteriorly from the spinous process of the third thoracic vertebra and goes forward and down to the junction of the bony and cartilaginous parts of the VI rib. IN
the right lung border between the upper and lower lobes is the same. At the point of its intersection with the wing
the line separates the furrow separating the middle part. It goes horizontally to the junction IV
ribs with sternum. The lower limit of the right lung is slightly above the border of the left, about the height of the ribs.
RESPIRATORY MUSCLES - arbitrary striated muscles that make periodic changes in chest volume.
The diaphragm is a flat muscle that separates the thoracic cavity from the abdomen. It is important for the process of respiration, because, shrinking, it increases the volume of the thoracic cavity and provides air flow to the lungs.
The diaphragm is the main muscle that provides the process of breathing. It has several holes through which very important structures (esophagus, inferior vena cava, aorta) pass from the thoracic region to the abdomen. On the periphery of the diaphragm consists of muscles, and closer to the center they pass into the tendons. It, unlike other tendons of the body, is not attached to the bones.
