However, the proportion of skin participation in human breathing is negligible compared to the lungs, because the total surface of the body is less than 2 m 2 and does not exceed 3% of the total surface of the pulmonary alveol.
Basic component parts Respiratory organs are respiratory tract, lightweight, respiratory muscles, including a diaphragm. The atmospheric air entering into light humans are a mixture of gases - nitrogen, oxygen, carbon dioxide and some others (Fig. 2).
Fig. 2. The average values \u200b\u200bof the partial pressure of gases (mm Hg. Art.) In the dry
inhaled air, alveoli, in exhaled air and in the blood with muscle rest (middle part of the figure). Partial gas pressure in venous blood flowing from kidneys and muscles (bottom of the figure)
Partial gas pressure in gases is called pressure, which this gas would create in the absence of other components of the mixture. It depends on the percentage of gas in the mixture: the more, the higher the partial pressure of this gas. The partial pressure of oxygen * in alveolar air is 105 mm Hg. Art., and in venous blood - 40 mm Hg. Art., so oxygen diffuses from alveoli into blood. Almost all oxygen in the blood is chemically associated with hemoglobin. Partial oxygen pressure The tissues are relatively low, so it diffuses from the blood capillaries into the cloth, providing tissue respiration and energy conversion processes.
Carbon dioxide transport - one of the end products of metabolism - is similar in the opposite direction. Carbon dioxide is distinguished from the body through the lungs. Nitrogen in the body is not used. Partial oxygen pressure, carbon dioxide, nitrogen in atmospheric air and on different levels Oxygen transport schemes are represented in Fig. 2.
but - external cylinder, b. - Glass window for samples, in - internal cylinder, g. - air balloon for balancing the inner cylinder, d. - Water
Due to the diffusion, the composition of the alveolar air is continuously changing: the concentration of oxygen in it decreases, and the concentration of carbon dioxide increases. To maintain the respiratory process, the composition of gases in the lungs must be constantly updated. This happens when ventilation of the lungs, i.e. breathing in the usual sense of the word. When we do inhale, the volume of lungs increases and air flows from the atmosphere. In this case, the alveoli is expanding. In a state of rest in the lungs, with every breath, about 500 ml of air flows. This air volume is called respiratory volume. Light people have a specific capacity of the container, which can be used at enhanced breathing. After a calm breath, a person can breathe about 1500 ml of air. This volume is called reserve inhale. After a calm exhalation, it is possible by doing effort, breathe about 1500 ml of air. it reserve exhalation. The respiratory volume and the backup volumes of inhalation and exhalation are amounting to little Life Capacity (Jack). IN this case It is equal to 3500 ml (500 + 1500 + 1500). To measure the jam, do especially deep breath And after it is the maximum exhalation in the tube special device - spirometer. Measurements are made in the standing position at rest (Fig. 3). The magnitude of the gear depends on the floor, age, body size and training. This indicator fluctuates widely, constituting on average 2.5-4 liters in women and 3.5-5 liters in men. In some cases, people are very high height, for example, basketball players can reach 9 liters. Under the influence of training, for example, when performing special breathing exercises, Zappa increases (sometimes even 30%).
Fig. 4. Nomogram Miller to determine the proper lung life capacity
We can determine the Miller nomogram (Fig. 4). To do this, it is necessary to find its growth on the scale and combine it with a straight line with age (separately for women and men). This straight line will cross the lung life capacity scales. An important indicator in physical performance studies is lone respiratory volume, or lighting lungs. Lung ventilation call the actual amount of air, which different conditions It passes through the lungs for 1 min. Alone pulmonary ventilation is 5-8 l / min.
Man is able to manage his breathing. You can briefly delay it or strengthen it. Ability to enhance breathing is measured by the value maximum pulmonary ventilation (MLV). This value, like the jam, depends on the degree of development of the respiratory muscles. In physical work, pulmonary ventilation increases and reaches 150-180 l / min. The harder work, the more pulmonary ventilation.
Elasticity of lung pretty much depends on the forces of the surface tension of the liquid, wetting interior surface Alveol (S \u003d 5 x 10-2 N / m). Nature itself took care of facilitating breathing, and created substances that reduce surface tension. They are synthesized by special cells located in the walls of Alveol. The synthesis of these superficial substances (surfactant) goes throughout the human life.
In those rare cases when the newborn is missing in light cellsThe surfactant, the child cannot make the first breath on his own and dies. Due to the lack or absence of surfactants in Alveoli, about half a million newborns in the world dies every year and without making the first breath.
However, some animals breathing lightly, and without surfactant. First of all, this refers to cold-blooded - frogs, snakes, crocodiles. Since these animals do not have to spend energy on heating, their oxygen needs are not as high as the warm-blooded, and therefore the surface area of \u200b\u200bthe lungs is less. If in a lung person, the surface area of \u200b\u200bthe surface of contact 1 cm 3 of air with blood vessels is about 300 cm 2, then the frog is only 20 cm 2.
The relative decrease in the lung area, which is per unit of its volume, is associated with the fact that the diameter of the alveoli is about 10 times more than that of warm-blooded. And from the law of Laplace ( p. \u003d 4A / R) It follows that additional pressure that must be overcome when inhaling is inversely proportional to the alveoli radius. A large radius of alveoli in cold blood allows them to be easy to breathe even without reducing the value p. Due to the surfactant.
No surfactant and in lung birds. Birds - warm-blooded animals and lead an active lifestyle. Almost the need for birds in oxygen is higher than that of other vertebrates, including mammals, and during the flight it increases many times. The respiratory system of birds is able to saturate blood oxygen even when flying at high altitude, where its concentration is significantly less than at sea level. Any mammals (including a person), being at such a height, begin to experience oxygen starvationdramatically reduce their motor activityAnd sometimes even fall into a seventhous state. How does light birds manage, in the absence of surfactants, to cope with this difficult task?
In addition to ordinary lungs, birds have an additional system consisting of five or more pairs of thin-walled air bags associated with the lungs. The cavities of these bags are widely branched in the body and enter into some bones, sometimes even in small dice the phalange of the fingers. As a result, the respiratory system, such as duck, occupies about 20% of the body volume (2% light and 18% air bags), while a person is only 5%. The walls of the air bags are poor vessels and in gas exchange are not involved. Air bags not only contribute to blowing air through the lungs in one direction, but also reduce the density of the body, friction between its individual parts contributes to the efficient cooling of the body.
Easy birds are built from the blood vessels surrounded by blood vessels parallel to the thin tubes open on two sides - air capillaries departing from Parabronov. During the inhalation, the volume of the front and rear air bags increase. The air from the trachea comes directly to the rear bags. The front bags with the main bronchine are not communicated and filled with air emerging from the lungs (Fig. 5, but).
Fig. five . Air movement in the bird's respiratory system: but - inhale, b. - Exhaust
(K1 and K2 - valves changing air traffic)
With the exhalation, the message of the front bags with the main bronchus is restored, and the rear is interrupted. As a result, during exhalation, the air through a light bird flows in the same direction as inhaling (Fig. 5, b.). During respiration, only the volume of air bags change, and the volume of the lung remains almost constant. It becomes clear why there is no surfactant in the bird lungs: they are there just nothing, because Inflatable lungs no need.
Some organisms use air not only for breathing. The body of fish, haggard, dwelling in the Indian Ocean and the Mediterranean Sea, is devoid of numerous needles - modified scales. In the calm state of the needle more or less tightly adjacent to the body. With the danger, the needle rustles to the surface of the water and, gaining air into the intestines, turns into a bloated ball. At the same time, the needles are lifted and sticking out in all directions. The fish holds near the surface of the water, tipping up up with a belly, and part of her body protrudes over the water. In this position, the predators are protected from predators both from below. When the danger passes, the needle releases the air, and its body takes ordinary sizes.
The air shell of the Earth (atmosphere) is held near the Earth at the expense of attraction forces and puts pressure on all the bodies with which it comes into contact. The body of a person is adapted to atmospheric pressure and poorly transfers its decrease. When lifting in the mountains (4 thousand m, and sometimes below), many people feel bad, attacks appear " mountain sickness": It becomes difficult to breathe, often from the ears and nose there is blood, Possible loss of consciousness. Since the articular surfaces are tightly adjacent to each other (in the articular bag covering the joints, the pressure is lowered) due to atmospheric pressure, then high in the mountains, where the atmospheric pressure is strongly reduced, the joints of the joints are frustrated, the hands and feet are bad "listened", dislocation . Climbers and pilots, climbing at a large height, take oxygen appliances with them and before lifting specially trained.
In the program special training Cosmonauts include mandatory training in the barocamera, which is a hermetically closing steel chamber, connected to a powerful pump, creating in its increased or reduced pressure. IN modern medicine The barocamera is used in the treatment of many diseases. Clean oxygen is supplied to the chamber, and high pressure is created. Due to the diffusion of oxygen through the skin and the lungs significantly increases its voltage in tissues. This treatment method is very effective, for example, with a wound infection (gas gangrene) caused by anaerobic microorganisms for which oxygen is a strong poison.
At those heights where modern space ships fly, air is practically no, so the cab cabins are made hermetic, and normal pressure and composition of air, humidity and temperature are created and maintained. The tightness of the cabin leads to tragic consequences.
Soyuz-11 spacecraft with three cosmonauts on board (Dobrovolsky, V. Volkov, V. Patsayev) was brought to an near-earth orbit on June 6, 1971, and on June 30, when returning to Earth, the crew died as a result of depressurization of the descent apparatus After separating compartments at an altitude of 150 km.
Some information about breathing
Man breathes rhythmically. The newborn child performs respiratory movements 60 times in 1 min, a five-year-old - 25 times in 1 min, in 15-16 years of breathing the frequency decreases to 16-18 per 1 min and is preserved such up to old age when it is expensive again.
In some animals, the respiratory frequency is much lower: Condor makes one respiratory movement in 10 s, and chameleon is 30 minutes. Light chameleon is connected by special bags in which he gains air and is very inflated. Low respiratory frequency allows chameleon for a long time to detect its presence.
At rest and at normal temperature, a person consumes in 1 min about 250 ml of oxygen, per hour - 15 liters, per day - 360 liters. The amount of oxygen consumed is inconceive - during the day it is greater than at night, even if a person sleeps in the afternoon. Probably, this is the manifestation of daily rhythms in the life of the body. Lying a person consumes in 1 hour about 15 liters of oxygen, standing - 20 liters, with a calm walk - 50 liters, when walking at a speed of 5 km / h - 150 liters.
At atmospheric pressure, a person can breathe pure oxygen about one day, after which it occurs pneumoniaAnchoring death. With a pressure of 2-3 atm, a person can breathe clean oxygen no more than 2 hours, then there is a violation of coordination of movements, attention, memory.
For 1 min through the lungs, 7-9 l of air passes in the norm, and the trained runner is about 200 liters.
Internal organs With enhanced work require increased oxygen supply. With tense activities, oxygen consumption with heart increases 2 times, liver - 4 times, kidneys - 10 times.
With each breath, a person performs a job sufficient to lift the cargo weighing 1 kg to a height of 8 cm. Using the work performed for 1 hour, it would be possible to raise this cargo to a height of 86 m, and overnight - by 690 m.
It is known that the respiratory center is excited by increasing the concentration of carbon dioxide. If the concentration of carbon dioxide in the blood is reduced, a person may not breathe longer than usual. This can be achieved by rapid breathing. Diverners are used by such a reception, and experienced pearl catches can remain under water 5-7 minutes.
Dust is everywhere. Even at the top of the Alps, 1 ml of air contains about 200 dust. In the same amount of urban air containing more than 500 thousand dust particles. The wind transfers dust on very distant distances: for example, in Norway, dust from sugar was found, and in Europe - volcanic dust from Indonesia Islands. Dust particles are delayed in respiratory organs and can lead to various diseases.
In Tokyo, where there are 40 cm 2 outdoor surface for each resident, the police work in oxygen masks. In Paris, pure air booths are installed for passersby. The pathologists will recognize Parisians when opening on black light. In Los Angeles, plastic palm trees are installed on the street, as living dying due to the large air pollution.
To be continued
* This refers to the partial pressure of the air oxygen in which it is in equilibrium with oxygen dissolved in the blood or other medium, also called the oxygen voltage in this medium.
Tests
706-01. Vertebrate animals with a three-skame heart, the reproduction of which is closely connected with water, are combined into class
A) bone fish
B) mammals
C) Presbysey
D) amphibians
Answer
706-02. Which class is animals, the scheme of the heart structure of which is shown in the figure?
A) insects
B) cartilage fish
C) amphibians
D) birds
Answer
706-03. A sign that distinguishes amphibians from fish is
A) cold-bloodedness
B) the structure of the heart
C) development in water
D) closedness blood system
Answer
706-04. Amphibians differ from the presence of fish
A) brain
B) closed circulatory system
C) paired lungs in adult individuals
D) senses
Answer
706-05. What sign among the listed distinguishes most of the animal class amphibians from mammals?
B) outdoor fertilization
C) sexual reproduction
D) use for habitat of the aquatic environment
Answer
706-06. Reptiles in the process of evolution acquired, in contrast to amphibians,
A) closed blood system
B) high fertility
C) a large egg with germ shells
D) threehow heart
Answer
706-07. If in the process of evolution in the animal, a heart depicted in the figure was formed, then the animal respiratory authorities should be 
A) lungs
B) leather
C) Light bags
D) Zhabry
Answer
706-08. What group of animals reproduction is not related to water?
A) undecented (lancing)
B) bone fish
C) amphibians
D) Presbysey
Answer
706-09. What animals the development of the embryo is completely completed inside the egg?
A) bone fish
B) Tailed amphibians
C) fucking amphibians
D) Presbysey
Answer
706-10. Vertebrate animals with a three-dimensional heart whose reproduction is not related to water, unite into class
A) bone fish
B) mammals
C) Presbysey
D) amphibians
Answer
706-11. Vertebrate animals with non-permanent body temperature, light breathing, three-dimensional heart with an incomplete partition in the ventricle belong to the class
A) bone fish
B) amphibians
C) Presbysey
D) cartilaginous fish
Answer
706-12. Reptile, unlike amphibians, peculiar
A) external fertilization
B) internal fertilization
C) development with the formation of larvae
D) body separation on the head, torso and tail
Answer
706-13. Which of the listed animals is cold-blooded?
A) hinting lizard
B) Amur Tiger
C) steppe fox
D) ordinary wolf
Answer
706-14. Which class attract animals having dry skin with horny scales and three-chamber heart with an incomplete partition?
A) Presbysey
B) mammals
C) amphibians
D) birds
Answer
706-15. Birds differ from the reptiles presence
A) inner fertilization
B) central nervous system
C) two circles of blood circulation
D) constant temperature Body
Answer
706-15. What sign in the structure is similar to modern reptiles and birds?
A) air filled bones
B) dry leather devoid of glands
C) tail department in the spine
D) small teeth in the jaws
Answer
706-16. Which animal gas exchange between the atmospheric air and blood takes place through the skin?
A) Kakatak
B) Triton
C) crocodile
D) Gorbusha
Answer
706-17. What group of animals is the heart consists of two cameras?
A) fish
B) amphibians
C) Presbysey
D) mammals
Answer
706-18. The development of a cub in the uterus occurs at
A) birds of prey
B) Presbysey
C) amphibians
D) mammals
Answer
706-19. For representatives of what class of chord animals is characteristic of skin breathing?
A) amphibians
B) Reptile
C) birds
D) mammals
Answer
706-20. A sign of the class of amphibians is
A) chitinist
B) naked skin
C) fatigress
D) paired limbs
Answer
706-21. What featured representatives of the class amphibians differ from other vertebrates?
A) spine and free limbs
B) pulmonary breathing and clock
C) naked mucous skin and outdoor fertilization
D) closed circulatory system and two-chamber heart
Answer
706-22. What feature among listed distinguishes animal animals reptiles from animal class mammals?
A) closed circulatory system
B) non-permanent body temperature
C) development without transformation
D) use for the habitat of the ground-air environment
Breathing physiology 1.
1. The essence of breathing. The mechanism of inhalation and exhalation.
2. The occurrence of negative pressure in the parole space. Pneumothorax, atelectasis.
3. Types of breathing.
4. Liquid life capacity and ventilation.
n. 1. The essence of breathing. The mechanism of inhalation and exhalation.
n A combination of processes that provide an exchange of oxygen and carbon dioxide between the external environment and tissues of the body is called breathing , and the totality of organs providing breathing - respiratory system.
n. Types of breathing:
n Cellular - in unicellular through the entire surface of the cell.
n skin - in multicellular organisms (worms) through the entire surface of the body.
n trachene - in insects through special tracheas, passing along the side surface of the body.
n Gaberry - in fish through the gills.
n pulmonary - in amphibians through the lungs.
n in mammals through specialized respiratory organs: nasopharynk, larynx, trachea, bronchi, lungs, and also participate rib cage, diaphragm and muscle group: inspirators and expirators.
n Light (0.6-1.4% body weight) - paired organs, have a share (right - 3, left - 2), divided by lobes (each by 12-20 acinuses), bronchi branches on bronchiols, ends with alveoli .
n Morphological and Functional Unit of Lung - acinus (Lat. Acinus - Grape Berry)- branching of respiratory bronchioles on alveolar moves, ending with 400-600 alveolar bags.
n alveoli filled with air and do not fall due to the presence of surfactants on their walls - surfactants (phospholipoprotein or lipopolysaccharides).
n. Respiratory steps:
n a) pulmonary ventilation - gas exchange between light and external environment;
n b) Gas exchange in the lungs between alveolar air and capillaries of a small circle of blood circulation;
n c) transport O2 and CO2 blood;
n d) the exchange of gases between the blood of the capillaries of a large circle of blood circulation and tissue liquid;
n D) intracellular breathing - a multistage enzyme process of oxidation of substrates in cells.
n are the main physical process that provides the movement of O2 from external environment to cells and CO2 in the opposite direction - this diffusion , i.e., gas movement in the form of a dissolved substance according to concentration gradients.
n. Inhale - inspiration .
n The movement of air into the lungs and from the lungs into the environment is due to a change in pressure inside the lungs. When the lungs are expanding, the pressure in them becomes below the atmospheric (by 5-8 mm Hg. Art.) And the air is saturated into the lungs. The lungs themselves do not have muscle tissue. The change in the volume of the lungs depends on the change in the volume of the chest, i.e. Lightweight passively follow the changes in the chest. When inhaling the chest expands in vertical, sagittal and frontal directions. When cutting inspirator muscle (inhabitants) - external intercostal and diaphragms, the ribs rise up, and the chest expands. The diaphragm takes a cone-shaped form. All this helps to reduce pressure in the lungs and sucking air. The thickness of the alvetol is small, so the gases are easily diffused through the wall of the alveol.
n. Exhaust - expiration .
n When you exhale, the muscles-inspirators and the chest, due to their severity and the elasticity of the rib cartilage returns to its original position. The diaphragm relaxes, the domestic form. Thus, alone exhale occurs passively, due to the end of the breath.
n With forced breathing, the exhale becomes active - increases by reducing the muscles expirators (exhaust) - internal intercostal muscles, abdominal muscles - external and internal oblique, transverse and straight abdominal, dorsal gear. The pressure in the abdominal cavity increases, which pushes the diaphragm into the chest cavity, the ribs are lowered, approach to each other, which reduces the amount of the chest.
n When the lungs fall down, the air is squeezed, the pressure in them becomes above atmospheric (3-4 mm Hg. Art.).
n. 2. The occurrence of negative pressure in the parole space. Pneumothorax, atelectaz
n Light in the chest is separated by pleural sheets: visceral - adjacent to the lungs, parietal - wipes the chest from the inside. Between sheets - pleural cavity. It is filled with pleural fluid. Pressure in the pleural cavity is always lower than atmospheric by 4-10 mm Hg. Art. (in the lungs of 760 mm Hg. Art.). This is due to: 1) more fast growth chest in comparison with the lungs in postnatal ontogenesis; 2) elastic pull(elastic voltage) of the lungs, i.e. by force opposing them with air stretching. The pleural cavity is sealed from ambient.
n When air from the pleural cavity (pr. When injected), pressure in the pleural cavity with atmospheric is aligned - pneumothorax However, the lung falls down - atelectaz And breathing may stop.
n The negative pressure of the pleural cavity is formed at birth. With the first breath, the chest expands, the lungs are straightened, since they are hermetically separated - negative pressure is formed in the pleural cavity. The fetus are lungs are in the saving condition, the chest is flattened, the head of the ribs outside the articular fifth. When birth in the blood, the fetus accumulates carbon dioxideHe excites the breathing center. Hence the impulses come to the muscles - inspirators that are reduced, the heads of the ribs are included in the articular pits. The chest increases in the volume, light straightened.
n The relationship between the breasts and the volume of the lung in the respiratory process is usually illustrated by physical donders models:
n 1. Glass cap,
n 2. From above - a plug with a hole,
n 3. bottom - elastic film with ring,
n 4. Inside the cap - light rabbit.
n With an increase in the volume inside the cap due to the stretching of the elastic film, the pressure in the cavity of the cap decreases, the air flows through the hole in the traffic jam, they are expanding and vice versa.
n. 3. Types of breathing.
n. 1. Breast or root - change in the volume of the chest occurs mainly due to intercostal muscles (expirators and inspirators). Characterized for dogs and women.
n. 2. Abdominal or diaphragmal - change in the volume of the chest occurs mainly due to the diaphragm and muscles abdominal press. Characterized for men.
n. 3. Mixed or busty - The change in the volume of the chest occurs equally in the reduction of intercostal muscles, the diaphragms and the muscles of the abdominal press. Characterized for farm animals.
n breathing types are diagnostic: when damaged by the abdominal organs or breast cavity change.
n. 4. Liquid life capacity and ventilation.
n. Light Life Capacity (Jack) consists of 3 volumes of air entering and distinguished from the lungs when breathing:
n. 1. Respiratory - air volume with a calm breath and exhale. Small animals (dogs, MRCs) - 0.3-0.5 liters, in large (cattle, horse) - 5-6 liters.
n. 2. Additional or reserve inspire– The amount of air that falls into the lungs at the maximum breath after a calm breath. 0.5-1 and 5-15 liters.
n. 3. Reserve exhalation– Air volume with maximum exhalation after calm exhalation. 0.5-1 and 5-15 liters.
n Jack is determined by measuring the volume of maximum exhalation after the preceding maximum inhalation by the method of spirometry. In animals, it is determined by inhalation of the gas mixture with high content Carbon dioxide.
n. Residual volume - The volume of air that remains in the lungs even after the maximum exhalation.
n. Air "Harmful" or "Dead" space - the volume of air that does not participate in gas exchange and is in the upper part of the breathing apparatus - nasal cavity, throat, trachea (20-30%).
n. The value of "harmful" space:
n 1) The air is warmed (abundant supply of blood vessels), which prevents the supercooling of the lungs;
n 2) The air is cleared, moistened (alveolar macrophages, many mucous glands);
n 3) With irritation of flickering epithelium cilia, sneezing occurs - reflex removal harmful substances;
n 4) Receptors olfactory analyzer ("Olfactory labyrinth");
n 5) Regulation of the volume of inhaled air.
n process of updating the gas composition of alveolar air during inhalation and exhalation - lighting lungs .
n Intensity of ventilation is determined by the depth of the inhalation and frequency respiratory movements.
n. Depth inhale determine the amplitude of the movements of the chest, as well as measuring pulmonary volumes.
n. Frequency of respiratory movements calculated by the number of chest excursions for a certain period of time (4-5 times less heart rate).
n horse (in min) - 8-16; CRS - 12-25; MRC - 12-16; Pig - 10-18; Dog - 14-24; Rabbit - 15-30; Furst - 18-40.
n. Lone respiratory volume - This is a product of air respiratory volume on the frequency of respiratory movements in min.
n Ave.: Horse: 5 l x 8 \u003d 40 l
n. Respiratory Study Methods:
n 1. Pneumography- Registration of respiratory movements with a pneumograph.
n 2. Spirometry - Measure respiratory volumes With the help of spirometers.
Lecture 25.
Physiology of breathing 2.
1. Gas exchange between alveoli and blood. State of blood gases.
2. Gas transport and factors determining it. Fabric breathing.
3. Functions of the lungs that are not associated with gas exchange.
4. Respiratory regulation, respiratory center and its properties.
5. Features of breathing in birds.
Gas exchange between alveoli and blood. State of blood gases.
In alveoli light O2 and CO2 exchange between air and blood capillaries of a small circle of blood circulation.
Exhaled air contains more O2 and less CO2 than alveolar air, because The air of a harmful space is mixed to it (7: 1).
The magnitude of the diffusion of gases between alveoli and blood is determined by purely physical laws acting in the gas system - liquid separated by a semi-permeable membrane.
The main factor determining the diffusion of gases from the air alveoli into blood and from the blood in the Alveola is the difference in partial pressure, or gradient of partial pressure. Diffusion comes from a higher partial pressure area to a lower pressure area.
Gas composition of air
Partial pressure (Lat. Partialic – partial) - this is the pressure of a gas in the gases mixture, which it would have at the same temperature, occupying one entire volume.
P \u003d ra x a / 100,
where p is the partial pressure of the gas, the atmospheric pressure, and the volume of the gas included in the mixture in%, 100-%.
Р О2 in jail. \u003d 760 x 21/100 \u003d 159.5 mm Hg. Art.
P CO2 in jail. \u003d 760 x 0.03 / 100 \u003d 0.23 mm Hg. Art.
P N2 in jail. \u003d 760 x 79/100 \u003d 600.7 mm Hg. Art.
Equality R O2 or P CO2 in interacting media never occurs. In the lungs there is a permanent influx fresh air Due to the breathing movements of the chest, in the tissues, the voltage difference is maintained by oxidation processes.
The difference between the partial pressure O2 in the alveolar air and the venous blood of the lungs is: 100 - 40 \u003d 60 mm Hg, which causes diffusion O2 into the blood. With a voltage difference O2 1 mm Hg. Art. The cow in the blood passes 100-200 ml O2 in 1 min. The average need for an animal in O2 alone is 2000 ml in 1 min. Pressure difference in 60 ml of RT. Art. More than enough to saturate blood o2 as alone and under load.
60 mm Hg.st. x 100-200 ml \u003d 6000-12000 ml o2 per min
Lecture number 15. Physiology of breathing.
1.
2. External breathing (Lung Ventilation).
3.
4. Transportation of gases (O2, CO2) blood.
5. Exchange of gases between blood and tissue fluid. Fabric breathing.
6. Respiratory regulation.
1. Essence of breathing. Respiratory system.
Breath physiological functionproviding gas exchange between the body and the external environment, and the combination of organs of the respiratory system involved in gas exchange.
Evolution of the respiratory system.
1.At single-celled organisms Breathing is carried out through the surface (membrane) of the cell.
2.At lower multicellular animals Gas exchange goes through the entire surface of the external and internal (intestines) of the cell cells.
3.In insects The body is covered with a cuticle and therefore there are special breathing tubes (trachea), penetrating the whole body.
4.From fish Respiratory authorities are gills - numerous leaflets with capillaries.
5.For amphibians Air bags appear (lungs), in which the air is updated using respiratory movements. However, the main exchange of gases goes through the skin surface and is 2/3 of the total volume.
6.Pretty, birds and mammals The lungs are already developed well, and the skin becomes protective cover and through it the gas exchange does not exceed 1%. Horses with high exercise Breathing through the skin increases to 8%.
Respiratory system.
The breathing apparatus of mammals is a combination of organs performing airconducting and gas exchange functions.
Upper air paths: nasal cavity, mouth, nasopharynk, larynx.
Bottom air: trachea, bronchi, bronchioles.
Gas exchange function Performs respiratory porous fabric - lung parenchyma. The structure of this tissue includes pulmonary bubbles - alveola.
the wall of the air paths has cartilage isto And their lumen never falls down. Mucous membrane respiratory tube Vostlavna fiscal epithelium with cilia. Fuchea before entering the lungs dichotomicallydivided into two main bronchi (left and right), which are subsequently divided and form bronchial tree. Ends the division of the final (terminal) bronchioles (diameter up to 0.5-0.7 mm).
Lungs Arranged in the chest cavity and have the shape of a truncated cone. The base of the lung is drawn back and adjacent to the diaphragm. Outside the lungs are covered with a serous shell - visceral Pleverra. Parietal pleura (bone) It lifts the chest cavity and grips tightly with the Röbert wall. There is a sliding space between these sheets (5-10 microns) - pleural cavity filled with serous fluid. Space between right and left lung called mediofream. Here are the heart, trachea, blood vessels and nerves. Lights are divided into shares, segments and slices. The degree of severity of such division among various animals is non-etinakov.
Morphological and functional unit of light is acinus (Lat. Acinus - Grape Berry). The acinus includes remoditor (respiratory) bronchio and alveolar moves, which end out alveolar bags. One acinus contains 400-600 alveoli; 12-20 acinuses form a lung slicing.
Alveola - These are bubbles, the inner surface of which is lined with single-layer flat epithelium. Among epithelial cells are distinguished : 1st order alveolocytes, which together with the endothel of the capillaries of the lungs form Aerhematic barrier and 2nd order alveocytes perform a secretory function, highlighting biologically active substance Surfactant. Surfactant (phospholipoproteins - superficially active substance) Lines the inner surface of the alveoli, increases the surface tension and does not allow alveolum to fall.
Functions of airways.
Aerial paths (they are delayed up to 30% of the inhaled air) do not take part in gas exchange and call them "Harmful" space. However, the upper and lower airways play a large role in the vital activity of the body.
It takes warming, moisturizing and purification of inhaled air. This is possible due to a well-developed mucous membrane of the respiratory tract, which is plentiful vascularized Contains glazing cells, mucous glands and a large number of Carnish ciliary epithelium. In addition, there are an olfactory analyzer receptors, cough, sneezing protective reflex receptors, sneezing, snird and irritant (irritation) receptors. They are located in bronchioles and react to dust particles, mucus, caustic substances. When irritating irritant receptors, there is a feeling of burning, dedication, cough appears and breathing is surrounded.
Gas exchange between the organism and the external environment is ensured by a set of strictly coordinated processes included in the structure of breathing higher animals.
2. External breathing (Easy ventilation) The constant process of updating the gas composition. In alveolar air, which is carried out at inhale and exhale.
Light fabric It does not have active muscle elements and therefore its increase or decrease in the volume occurs passively in the beat of the movements of the chest (inhalation, exhalation). This is due to negative intrapleural pressure (below atmospheric: when inhaling 15-30 mm Hg. Art., With exhalation on 4-6 mm Hg. Art.) In a hermetically closed chest cavity.
The mechanism of external breathing.
Act inhale (lat. Inspiration - inspiration) It is carried out due to an increase in the volume of the chest. The muscles of inspirators (inhaples) take part in this: outdoor interrochemical muscles and diaphragms. With forced breathing, muscles are connected: rifter Röbeber, staircase muscle, dorzal toothed inhal.The amount of the chest at the same time increases in three directions - vertical, sagittal (front-facing) and frontal.
Exemption act (lat. Expiration - expiration) In the state of physiological rest wears a predominantly passive character. As soon as the muscles are relaxed, the chest due to their gravity and the elasticity of the ribic cartilage returns to its original position. The diaphragm relaxes and the dome it becomes convex again.
With the forced breathing, the acts of exhaust contribute to the muscles of expirators: internal interrogostere, outdoor and internal oblique, transverse and straight muscles abdominal wall, Dorzal toothed exhacer.
Types of breathing.
Depending on the transformation of certain muscles involved in the respiratory movements, distinguish three types of breathing:
1 - Breast (Ryabe) Type of Breath It is carried out with a reduction in the external interrochemical muscles and the muscles of the chest belt;
2 - abdominal (diaphragmal) breathing type - reductions in the diaphragm and abdominal muscles;
3 - Mixed (Röbebno) type of breathing Most often occurs in farm animals.
For various diseases The type of breathing may vary. In case of the disease of the breastfeeding organs, the diaphragmal type of breathing prevails, and with diseases of the abdominal organs - the Riber type of breathing.
Frequency of respiratory movements.
Under the frequency of breathing, the number of respiratory cycles (breathing) is 1 minute.
Horse 8 - 12 Dog 10 - 30
Croup horn. Cattle 10 - 30 Rabbits 50 - 60
Sheep 8 - 20 chickens 20 - 40
Pig 8 - 18 ducks 50 - 75
Man 10 - 18 Mouse 200
It should be noted that the table shows the average indicators. The frequency of respiratory movements depends on the type of animal, breed, productivity, functional state, time of day, age, ambient temperature, etc.
Light volumes.
Distinguish the overall and vital capacity of lungs. The life capacity of the lungs (Flag) is made up of three volumes: respiratory and backup volumes of inhale and exhalation.
1.Respiratory volume - This is the volume of air that can be calm, to breathe and breathe and exhale.
2.Reserve inhalation - This is the air that can be additionally inhaled after a calm breath.
3.Reserve output - This is the volume of air that can be used to breathe as much as possible after a calm exhalation.
After the complete as deep emission in the lungs remains more of the air - residual volume. The amount of the fault and the residual air volume make up the overall capacity of lungs.
The sum of the residual air volume and the reserve volume of exhalation is called alveolar air (functional residual capacity).
Light volumes (in liters).
Horse man
1. Respiratory V 5-6 0.5
2. Reserve V inhale 12 1.5
3. Reserve V exhalation 12 1.5
4. Residual V 10 1
Ventilation lungs - This is an update of the gas composition of alveolar air when inhaling and exhale. When evaluating the intensity of ventilation, the lungs use current volume of breathing (The amount of air passing through light per 1 minute), which depends on the depth and frequency of respiratory movements.
Horses have a breathing volume in rest 5-6 liters , breathing frequency 12 respiratory movements in 1 minute.
Hence: 5 L..*12=60 lithrov Current volume of breathing. With light work, it is equal 150-200 liters, With heavy work 400-500 liters.
During the breath, certain parts of the lungs are ventilated not all and with different intensity. Therefore, they are calculated the coefficient of alveolar ventilation - This is the ratio of the inhaled air to the alveolar volume. It should be borne in mind that when inhaling a 5 liter horse, 30% of the air remains in the air-free "harmful space".
Thus, 3,5 liters of inhaled air comes to alveoli (70% of 5 liters of respiratory volume). Therefore, the coefficient of alveolar ventilation is 3.5 liters: 22 liters. or 1: 6. That is, with each quiet breath, 1/6 alveoli is ventilated.
3. Diffusion of gases (gas exchange between alveolar air and blood circulation capillaries).
Gas exchange in the lungs is carried out as a result of diffusion Carbon dioxide (CO 2) from the blood in the alveoy of lung, and oxygen (O 2) from the alveoli into the venous blood capillaries of a small circle of blood circulation. The estimated way was established that about 5% of the inhaled air oxygen remains in the body, and about 4% carbon dioxide is released from the body. Nitrogen in the gas exchange does not accept participation.
Gas movement is determined purely physical laws (osmosis and diffusion), operating in the gas-liquid system separated by a semi-permeable membrane. At the heart of these laws, the continuity of partial pressure or the gradential pressure gradient of gases.
Partial Pressure (Lat. Partialis - Partial) - This is the pressure of one gas included in the gas mixture.
Diffusion of gases comes from the region more high pressure to the lower area.
Partial oxygen pressure in alveolar air 102 mm RT. Art., carbon dioxide 40 mm Hg. Art. In the venous blood capillary light tension O2 \u003d 40 mm RT. Art., CO2 \u003d 46 mm Hg. Art.
Thus, the difference in partial pressure:
oxygen (O2) 102 - 40 \u003d 62 mm Hg. Art.;
carbon dioxide (CO2) 46 - 40 \u003d 6 mm RT. Art.
Oxygen quickly goes through the light membranes and is fully connected to hemoglobin and blood becomes arterial. Carbon dioxide, despite a small difference, partial pressure has higher diffusion speed (25 times) From the venous blood in the lung alveoli.
4. Transportation of gases (O 2, CO 2) blood.
Oxygen, moving from the alveoli into blood, is in two forms - about 3% dissolved plasma and near 97% of red blood cells connected with hemoglobin (oxymemoglobin). Oxygen saturation is called oxygenation.
In one hemoglobin molecule, 4 iron atoms, therefore, 1 hemoglobin molecule can be connected to 4 oxygen molecules.
NN.b.+ 4O 2 ↔ NNb.(O 2) 4
Oxygemoglobin (NNB (O 2) 4) - Exhibits Property weak, easily dissociating acid.
The amount of oxygen in 100 mm of blood with a complete transition of hemoglobin to oxymemoglobin is called oxygen tank blood. It has been established that 1 g of hemoglobin may on average tie 1.34 mm oxygen. Knowing the concentration of hemoglobin in the blood, and it averages 15 g. / 100 ml, You can calculate the oxygen tank of blood.
15 * 1.34 \u003d 20.4 vol.% (Volume percent).
Carbon dioxide transport by blood.
The transfer of carbon dioxide with blood is difficult processin which take part erythrocytes (hemoglobin, carboangeez enzyme) and buffer blood systems.
Carbon dioxide is in the blood in three forms: 5% - physically dissolved; 10% - in the form of carbohemoglobin; 85% - in the form of potassium bicarbonates in erythrocytes and sodium bicarbonates in plasma.
CO 2 hitting the blood plasma from the tissue, immediately diffuses to the erythrocytes, where hydration is reacting with the formation of coalic acid (H 2 CO 3) and its dissociation. Both reactions are catalyzed by the enzyme carboangeyndrase, which is contained in red blood cells.
H 2 O + CO 2 → H 2 CO 3
carboangeeza
↓
H 2 CO 3 → H + + NSO 3 -
As the concentration of bicarbonate ions increases (NSO 3 -) In the erythrocytes, one part of them diffuses in the blood plasma and connects with buffer systems, forming sodium bicarbonate (NaHCO 3). Another part of the NSO 3 - remains in red blood cells and connects with hemoglobin (carbohemoglobin) and with potassium cations - potassium bicarbonate (KNSO 3).
In the capillaries, alveoli hemoglobin connects with oxygen (oxygemoglobin) is stronger acid that displaces coalic acid from all connections. Under the action of carboangeyndresses, its dehydration occurs.
H 2 CO 3 → H 2 O + CO 2
Thus, the carbon dioxide was dissolved and the carbon dioxide diffused during dissociation diffuses into alveolar air.
5. Gas exchange between blood and tissue fluid. Fabric breathing.
The exchange of gases between blood and tissues is also made due to the difference in partial pressure of gases (according to the laws of osmosis and diffusion). The bloodflow received here is saturated with oxygen, its voltage is 100 mm RT. Art. In the tissue fluid, the voltage of oxygen is 20 - 40 mm Hg. Art., and in cells its level falls up to 0.
Respectively: O 2 100 - 40 \u003d 60 mm Hg. Art.
60 - 0 \u003d 60 mm Hg. Art.
Therefore, oxygemoglobin repents the oxygen, which quickly goes into tissue fluid, and then into tissue cells.
Fabric breathing - This is a process biological oxidation in cells and tissues. Oxygen coming into tissues is affected by oxidation of fats, carbohydrates and proteins. Exempted energy accumulates in the form macroehergic connections - ATP. In addition to oxidative phosphorus, oxygen is also used with microsomal oxidation - in the microsomes of the endoplasmic reticulum of cells. Pori this final products of oxidative reactions become water and carbon dioxide.
Carbon dioxide, dissolving in a tissue fluid, creates voltage there 60-70 mm RT. Art., What is higher than in the blood (40 mm Hg. Art.).
CO 2 70 - 40 \u003d 30 mm Hg. Art.
Thus, the high oxygen stress gradient and the difference in the partial pressure of carbon dioxide in the tissue fluid and blood is the cause of its diffusion from the tissue fluid into the blood.
6. Respiratory regulation.
Respiratory Center -this is a combination of neurons located in all divisions of the central nervous system and participating in the regulation of breathing.
The main part of the "core" of the respiratory center of Mislavsky Located in oblong brain, in the field of reticular formation at the bottom of the fourth brain ventricle. Among the neurons of this center there is a strict specialization (distribution of functions). One neurons regulate the act of breath, other acts of exhalation.
Bulgarian respiratory pricetra has a unique feature - automatis which is maintained even with its full deaffreentment (after the exposure from various receptors and nerves).
In area varoliev Brosta situated "Pneumotactic Center". It does not have automation, but affects the activities of the neurons of the respiratory center of Mislavsky, alternately stimulating the activity of neurons of the act of inhalation and exhalation.
From the respiratory center are nervous impulses to motor mechanons the nucleus of the breast nerve (3-4 cervical vertebrae - center of the diaphragm muscles) and to motor mechanons located in lateral horns Breast Department spinal cord (innervates external and internal interrogostere muscles).
In the lungs (between the smooth muscles of the air ways and around the capillary of a small circle of blood circulation) there are three groups of receptors: stretching and savings, irritant, yuchstakapillary. Information from these receptors, about the status of light (stretching, decree), their filling air, hit irritant In the respiratory tract (gas, dust), changing blood pressure in the pulmonary vessels, on the afferent nerves falls into the respiratory center. It affects the frequency and depth of respiratory movements, manifestation of cough and sneezing protective reflexes.
Great importance in the regulation of breathing have gumoral factors. Changing the gas composition of blood react vascular Reflexogenic zones of carotid sinus, aortic and oblong brain.
An increase in the concentration of carbon dioxide in the blood leads to the excitation of the respiratory center. As a result, breathing is expensive - dISP (shortness of breath). Reducing the level of carbon dioxide in the blood slows down the rhythm of respiratory movements - Appeal.
What is gas exchange? Without it, almost no living being can do without it. Gas exchange in lungs and tissues, as well as blood helps to saturate cells nutrient substances. Thanks to him we get energy and vitality.
What is gas exchange?
To exist, air is needed by living organisms. It is a mixture of a plurality of gases, the main share of which is oxygen and nitrogen. Both of these gas are the most important components to provide normal vital activity organisms.
In the course of evolution different types developed their devices to obtain them, some have developed lungs, others - the gills, and the third use only skin Covers. With the help of these organs, gas exchange is carried out.
What is gas exchange? This is the process of interaction between the external environment and living cells, during which oxygen and carbon dioxide is met. During breathing, oxygen comes with air into the body. Saturating all cells and fabrics, he participates in oxidative reaction, turning into carbon dioxide, which is excreted from the body along with other metabolic products.
Gas exchange in the lungs
Every day we breathe more than 12 kilograms of air. This is helped by the lungs. They are the most voluminous organ capable of accommodating up to 3 liters of air for one full deep breath. Gas exchange in the lungs occurs with the help of alveoli - numerous bubbles that are intertwined with blood vessels.
Air falls into them through the upper respiratory tract, passing the trachea and bronchi. The capillaries are connected to alveolis take air and spread it through the circulatory system. At the same time, they give Alveola carbon dioxide, which leaves the body along with exhalation.
The exchange process between alveoli and vessels is called bilateral diffusion. It occurs in just a few seconds and is carried out due to the difference in pressure. In saturated atmospheric air, it is more, so it rushes to capillars. Carbon dioxide has a smaller pressure, which is why it is pushed into the alveoli.
Circulation
Without a circulating system, gas exchange in the lungs and tissues would be impossible. Our body is permeated with many blood vessels Various length and diameter. They are represented by arteries, veins, capillaries, venules, etc. In the vessels, blood continuously circulates, contributing to the exchange of gases and substances.
Gas exchange in the blood is carried out with two circles of blood circulation. When breathing, the air begins to move along a large circle. In the blood, it is transferred, attached to a special gemoglobin protein, which is contained in red blood cells.
From the alveolo air falls into the capillaries, and then in the artery, heading straight to the heart. In our body, it performs the role of a powerful pump, pumping blood saturated with oxygen to tissues and cells. They, in turn, give blood filled with carbon dioxide, directing it in venulaubles and veins back to heart.
Passing through the right atria deoxygenated blood Complete big circle. In the right ventricle, it begins on it. Blood moves into it moves in the arteries, arterioles and capillaries, where it makes an exchange of air with alveoli to start cycle re-on.
Exchange in tissues
So, we know what gas exchange lungs and blood is. Both systems carry gases and exchange them. But the key role belongs to the tissues. They occur the main processes that change chemical composition air.
Sats oxygen cells, which launches in them a number of redox reactions. In biology, they are called Krebs cycle. For their implementation, enzymes are needed, which also come along with blood.
In the course they are formed lemon, acetic and other acids, products for oxidation of fat, amino acids and glucose. This is one of the most important stageswhich accompanies gas exchange in tissues. During its flow, the energy required for the work of all organs and systems of the body is exempt.
Oxygen is actively used for reaction. Gradually, it is oxidized, turning into carbon dioxide - CO 2, which is distinguished from cells and tissues to blood, then into the lungs and atmosphere.
Gas exchange in animals
The structure of the body and systems of organs in many animals varies significantly. The most similar to the person are mammals. Small animals, such as planaria, do not have complex systems for metabolism. For breathing, they use external covers.
Breathing amphibians use skin cover, as well as mouth and lungs. In most animals living in water, gas exchange is carried out with the help of the gills. They are thin plates connected to capillaries and transmitting oxygen from water.
Arthropods, such as multi-ninexes, wets, spiders, insects, do not have the lungs. On the entire surface of the body, they have tracheas that direct the air directly to the cells. Such a system allows them to quickly move, without testing shorts and fatigue, because the process of energy formation is faster.
Gas exchange in plants
In contrast to animals, in plants, gas exchange in tissues includes consumption and oxygen, and carbon dioxide. Oxygen they consume in the process of breathing. Plants do not have special organs for this, so the air enters them through all parts of the body.
As a rule, the leaves have the largest area, and the main amount of air accounts for them. Oxygen enters them through small holes between cells, called the dust, is processed and is excreted already in the form of carbon dioxide, as in animals.
A distinctive feature of plants is the ability to photosynthesis. So, they can convert inorganic components to organic with light and enzymes. During photosynthesis, carbon dioxide is absorbed and oxygen is produced, so plants are real "factories" on air enrichment.
Features
Gas exchange is one of essential functions Any living organism. It is carried out with breathing and blood circulation, contributing to the release of energy and the exchange of substances. The features of the gas exchange are that it does not always occur equally.
First of all, it is impossible without breathing, its stop for 4 minutes can lead to violations of brain cells. As a result, the body dies. There are many diseases in which a violation of gas exchange is observed. Fabrics do not receive enough oxygen, which slows down their development and functions.
The unevenness of gas exchange is observed healthy people. It increases significantly with the enhanced work of the muscles. Literally in six minutes it reaches the utmost power and sticks to it. However, when the load gains, the amount of oxygen may begin to increase, which is also unpleasant to affect the health of the body.
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