Animal respiration, the meaning of respiration, the evolution of the respiratory organs, animal lungs, respiratory movements, gas exchange in the lungs and tissues, partial pressure and tension of gases, photo of animal respiration, report abstract. The essence of breathing. External breathing. Mechanism in

Respiratory system

GENERAL CHARACTERISTICS OF THE RESPIRATORY SYSTEM

The optimal gas composition of the body for metabolism - the relative constancy of carbon dioxide and oxygen in the alveolar air, blood and tissues - is ensured by the respiratory system. The respiratory system refers to the executive organs of the respiratory system and the regulatory mechanisms for maintaining the optimal gas composition of the body for metabolism. During metabolism, tissue cells constantly use oxygen and produce carbon dioxide. The respiratory system supplies tissues with oxygen and removes carbon dioxide.

The executive organs of the respiratory system are as follows:

inspiratory muscles - diaphragm, external oblique intercostal muscles, etc.;

expiratory muscles - internal oblique intercostal muscles, abdominal wall muscles, etc.;

rib cage;

bronchi and lungs;

trachea, larynx, nasopharynx, nasal passages - airways;

heart and blood vessels;

Airways. Provide passage of air into the lungs from the environment. Passing through them, the inhaled air is moistened, warmed or cooled, and cleaned of dust and microorganisms. The mucous membrane of the airway wall is covered with mucus; The trachea and bronchi are lined with ciliated epithelium. The incoming air comes into contact with mucus, to which air particles and microorganisms adhere; by the movement of the ciliated epithelium, the mucus moves towards the nasopharynx.

The functional unit of the lungs is the alveolus - the pulmonary vesicle. The alveolus has a hemispherical shape and a small wall thickness. The inner surface of the alveoli is lined with epithelium located on the basement membrane; on the outside it is densely braided with pulmonary capillaries. The inner surface of the alveoli is covered with a film of surfactant, which prevents their walls from sticking together during exhalation. Pulmonary vesicles are located at the ends of branched bronchioles, which pass into two bronchi. The alveoli form the spongy mass of the lungs. The lungs provide gas exchange between air and blood, i.e. exchange of oxygen and carbon dioxide.

PHYSIOLOGICAL PROCESSES OF BREATHING

Respiration is a set of physiological processes that ensure the entry of oxygen into the body and the removal of carbon dioxide, i.e. maintaining the relative constancy of carbon dioxide and oxygen in the alveolar air, blood and tissues.

Breathing includes the following physiological processes:

exchange of gases between the external environment and the mixture of gases in the alveoli;

exchange of gases between alveolar air and blood gases;

transport of gases by blood;

exchange of gases between blood and tissues;

tissue oxygen use and carbon dioxide production.

Exchange of gases between the external environment and the mixture of gases in the alveoli. The process of exchange of gases between the external environment and the mixture of gases in the alveoli is called pulmonary ventilation. The exchange of gases is ensured through respiratory movements - the acts of inhalation and exhalation. When you inhale, the volume of the chest increases, the pressure in the pleural cavity decreases and, as a result, air enters the lungs from the external environment. When you exhale, the volume of the chest decreases, the air pressure in the lungs increases, and as a result, alveolar air is forced out of the lungs.

The mechanism of inhalation and exhalation. Inhalation and exhalation occur because the volume of the chest cavity changes, sometimes increasing and sometimes decreasing. The lungs are a spongy mass consisting of alveoli and do not contain muscle tissue. They cannot contract. Respiratory movements are performed with the help of the intercostal and other respiratory muscles and the diaphragm.

When inhaling, the external oblique intercostal muscles and other muscles of the chest and shoulder girdle simultaneously contract, which ensures the elevation or abduction of the ribs, as well as the diaphragm, which moves towards the abdominal cavity. As a result, the volume of the chest increases, the pressure in the pleural cavity and in the lungs decreases and, as a result, air from the environment enters the lungs. The inhaled air contains 20.97% oxygen, 0.03% carbon dioxide and 79% nitrogen.

When exhaling, the expiratory muscles simultaneously contract, which ensures that the ribs return to their pre-inhalation position. The diaphragm returns to its pre-inhalation position. At the same time, the volume of the chest decreases, the pressure in the pleural cavity and in the lungs increases, and part of the alveolar air is displaced. Exhaled air contains 16% oxygen, 4% carbon dioxide, 79% nitrogen.

In animals, there are three types of breathing: costal, or chest, - when inhaling, abduction of the ribs to the sides and forward predominates; diaphragmatic, or abdominal, - inhalation occurs mainly due to contraction of the diaphragm; costabdominal - inhalation due to contraction of the intercostal muscles, diaphragm and abdominal muscles.

Exchange of gases between alveolar air and blood gases. The exchange of gases in the lungs between the alveolar air and the blood of the capillaries of the pulmonary circulation occurs due to the difference in the partial pressure of these gases. The oxygen concentration in the alveolar air is much higher than in the venous blood moving through the capillaries. Oxygen, due to the difference in partial pressure according to the law of diffusion, easily passes from the alveoli into the blood, enriching it. The blood becomes arterial. The concentration of carbon dioxide is much higher in venous blood than in alveolar air. Carbon dioxide, due to the difference in its voltage in the blood and its partial pressure in the alveolar air, according to the law of diffusion, penetrates from the blood into the alveoli. The composition of alveolar air is constant: about 14.5% oxygen and 5.5% carbon dioxide.

Gas exchange in the lungs is facilitated by the large surface of the alveoli and a thin layer of membrane from the endothelial cells of the capillaries and squamous alveolar epithelium, separating the gas environment and the blood. During the day, about 5000 liters of oxygen passes from the alveoli into the blood of a cow, and about 4300 liters of carbon dioxide enters the alveolar air from the blood.

Transport of gases by blood. Oxygen, having penetrated the blood, combines with the hemoglobin of red blood cells and is transported in the form of oxyhemoglobin by arterial blood to the tissues. Arterial blood contains 16...19 volume percent oxygen and 52...57 vol. % carbon dioxide.

Carbon dioxide moves from tissues into the blood, plasma and then into red blood cells. Part of it forms a chemical compound with hemoglobin - carbohemoglobin, and the other, under the action of the enzyme carbonic anhydrase, which is contained in erythrocytes, forms a compound - carbonic acid, which quickly dissociates into H+ and HCO3 ions. From the erythrocytes, HCO3~ enters the blood plasma, where it combines with NaCl or KC1, forming carbonic acid salts: NaHC0 3, KHC0 3. About 2.5 vol.% CO2 is in the plasma in a state of physical dissolution. In the form of these compounds, carbon dioxide is transported by venous blood from tissues to the lungs. Venous blood contains 58...63 vol.% carbon dioxide and 12 vol.% oxygen.

Exchange of gases between blood and tissues. In tissues, oxygen is released from a fragile connection with hemoglobin of erythrocytes and, according to the law of diffusion, easily penetrates into cells, since the oxygen concentration in arterial blood is much higher than in tissues. Here, oxygen is used to oxidize organic compounds to form carbon dioxide. The concentration of carbon dioxide in the tissues increases and becomes significantly higher than in the blood flowing to them. The carbon dioxide voltage is 60 mmHg. Art. in tissues and 40 mm Hg. Art. in arterial blood, therefore, according to the law of diffusion, it passes from tissues to blood. It is saturated with carbon dioxide, i.e. becomes venous.

EXTERNAL INDICATORS OF THE RESPIRATORY SYSTEM

The activity of the respiratory system is characterized by certain external indicators.

Respiratory rate per 1 min. For a horse it is 8...16, for cattle - 10...30, for a sheep - 10...20, for a pig - 8...18, for a rabbit - 15...30, for a dog - 10... 30, cats - 20...30, birds - 18...34, and in humans 12...18 movements per minute. Four primary pulmonary volumes: tidal, inspiratory reserve, expiratory reserve, residual volume. Accordingly, cattle and horses have approximately 5...6 l, 12...18,10...12, Yu...12 l. Four lung capacities: total, vital, inspiratory, functional residual. Minute volume. In cattle - 21...30 l and horses - 40...60 l. Content of oxygen and carbon dioxide in exhaled air. The tension of oxygen and carbon dioxide in the blood.

REGULATION OF BREATHING

The regulation of breathing is understood as maintaining the optimal content of oxygen and carbon dioxide in the alveolar air and in the blood by changing the frequency and depth of respiratory movements. The frequency and depth of respiratory movements are determined by the rhythm and strength of impulse generation in the respiratory center located in the medulla oblongata, depending on its excitability. Excitability is determined by the tension of carbon dioxide in the blood and the flow of impulses from the receptor zones of blood vessels, respiratory tract, and muscles.

Regulation of respiratory rate. Regulation of the frequency of respiratory movements is carried out by the respiratory center, which includes the centers of inhalation, exhalation and pneumotaxis; the center of inhalation plays the main role. In the center of inhalation, impulses are generated in rhythmic bursts per unit time, determining the breathing frequency. Impulses from the center of inspiration arrive to the inspiratory muscles and the diaphragm, causing an inhalation of such duration and depth that corresponds to the prevailing conditions and is characterized by a certain volume of air entering the lungs and the force of contraction of the inspiratory muscles. The number of impulses generated in the center of inspiration per unit time depends on its excitability: the higher the excitability, the more often the impulses are born, and therefore the more frequent the respiratory movements.

Everyone knows that people breathe through their lungs. What animals breathe with the help of their lungs you will learn in this article.

What animals breathe with their lungs?

Terrestrial vertebrates breathe through their lungs(amphibians, reptiles, birds, animals)

Animals and birds breathe with lungs, which are structured approximately the same as those of humans.

But marine mammals have lungs, but despite this, they can stay under water for a very long time. For example, a sperm whale can descend to a depth of about 1000 meters and remain under water for 1:00 because its giant lungs are capable of storing 1000 liters of air. Just like a whale, when breathing, it emits air and water vapor through the nasal opening and condenses in the cold - the result is a huge fountain 4 to 5 meters high.

With the help of the lungs, gas exchange occurs between the air in the lung cavity and the blood flowing through the pulmonary capillaries.

During inhalation, air containing oxygen enters the lungs. The lungs look like porous bags. In each lung (left and right), the bronchi branch very strongly, which end in numerous pulmonary vesicles. Each pulmonary vesicle is entangled in a network of blood vessels. From the lung, air oxygen bubbles pass into the blood, and carbon dioxide from the blood into the air. After carbon dioxide accumulates in the pulmonary bladder, exhalation occurs. The porous structure of the lungs makes it possible to increase their internal surface many times over.

Each cell of the body requires oxygen for its functioning. During the life of the body, decay products and carbon dioxide accumulate in it, which must be removed from the body. The essence of respiration is the absorption and assimilation of oxygen by animals and the release of carbon dioxide. There are pulmonary, or external, and tissue, or internal, respiration. Pulmonary respiration occurs through the respiratory system (nasal cavity, larynx).
From the nasal cavity, the air inhaled by the animal enters the larynx and passes into the trachea. In the area of ​​the 5th-6th vertebrae, the trachea is divided into two bronchi. They enter the right and left lungs, branch here repeatedly into smaller bronchi-bronchioles, ending in alveolar ducts with numerous alveoli (Fig. 5). The lungs are the main respiratory organ. In them, gas exchange occurs between air and blood. The lungs are located in the chest cavity, separated by the diaphragm from the abdominal cavity. The inside of the chest cavity is lined with pleura, one of the two layers of which is adjacent to the chest, the other to the lungs. The walls of the alveoli consist of a single layer of epithelium and are surrounded by a network of capillaries. The air in the alveoli is separated from the blood by the alveolar membrane and the capillary wall. Oxygen enters the blood through the walls of the alveoli, and carbon dioxide passes from the blood into the alveoli, which is removed from the lungs when exhaled. Gas exchange occurs according to the law of gas diffusion.

Atmospheric air contains about 21% oxygen and 0.03% carbon dioxide, and alveolar air contains 14.5 and 5.5%, respectively. Gases move from an area of ​​higher pressure to an area of ​​lower pressure. Breathing is regulated by the corresponding center located in the brain, and this act is carried out in two phases - inhalation and exhalation. The number of respiratory movements depends on the species characteristics of animals, their sex, age, level of productivity and environmental factors. On average, in 1 minute a horse makes 8-20 respiratory movements, a cow - up to 30, a sheep, goat and pig - 12-20, poultry - up to 50.

Abstract: Animal respiratory system

Respiratory system

GENERAL CHARACTERISTICS OF THE RESPIRATORY SYSTEM

The optimal gas composition of the body for metabolism - the relative constancy of carbon dioxide and oxygen in the alveolar air, blood and tissues - is ensured by the respiratory system.

The respiratory system refers to the executive organs of the respiratory system and the regulatory mechanisms for maintaining the optimal gas composition of the body for metabolism. During metabolism, tissue cells constantly use oxygen and produce carbon dioxide.

The respiratory system supplies tissues with oxygen and removes carbon dioxide.

The executive organs of the respiratory system are as follows:

inspiratory muscles - diaphragm, external oblique intercostal muscles, etc.;

expiratory muscles - internal oblique intercostal muscles, abdominal wall muscles, etc.;

rib cage;

bronchi and lungs;

trachea, larynx, nasopharynx, nasal passages - airways;

heart and blood vessels;

Airways.

Provide passage of air into the lungs from the environment. Passing through them, the inhaled air is moistened, warmed or cooled, and cleaned of dust and microorganisms. The mucous membrane of the airway wall is covered with mucus; The trachea and bronchi are lined with ciliated epithelium. The incoming air comes into contact with mucus, to which air particles and microorganisms adhere; by the movement of the ciliated epithelium, the mucus moves towards the nasopharynx.

The functional unit of the lungs is the alveolus - the pulmonary vesicle.

The alveolus has a hemispherical shape and a small wall thickness. The inner surface of the alveoli is lined with epithelium located on the basement membrane; on the outside it is densely braided with pulmonary capillaries. The inner surface of the alveoli is covered with a film of surfactant, which prevents their walls from sticking together during exhalation. Pulmonary vesicles are located at the ends of branched bronchioles, which pass into two bronchi.

The alveoli form the spongy mass of the lungs. The lungs provide gas exchange between air and blood, i.e. exchange of oxygen and carbon dioxide.

PHYSIOLOGICAL PROCESSES OF BREATHING

Respiration is a set of physiological processes that ensure the entry of oxygen into the body and the removal of carbon dioxide, i.e.

maintaining the relative constancy of carbon dioxide and oxygen in the alveolar air, blood and tissues.

Breathing includes the following physiological processes:

exchange of gases between the external environment and the mixture of gases in the alveoli;

exchange of gases between alveolar air and blood gases;

transport of gases by blood;

exchange of gases between blood and tissues;

tissue oxygen use and carbon dioxide production.

Exchange of gases between the external environment and the mixture of gases in the alveoli.

The process of exchange of gases between the external environment and the mixture of gases in the alveoli is called pulmonary ventilation. The exchange of gases is ensured through respiratory movements - the acts of inhalation and exhalation.

When you inhale, the volume of the chest increases, the pressure in the pleural cavity decreases and, as a result, air enters the lungs from the external environment. When you exhale, the volume of the chest decreases, the air pressure in the lungs increases, and as a result, alveolar air is forced out of the lungs.

The mechanism of inhalation and exhalation.

Inhalation and exhalation occur because the volume of the chest cavity changes, sometimes increasing and sometimes decreasing. The lungs are a spongy mass consisting of alveoli and do not contain muscle tissue.

They cannot contract. Respiratory movements are performed with the help of the intercostal and other respiratory muscles and the diaphragm.

When inhaling, the external oblique intercostal muscles and other muscles of the chest and shoulder girdle simultaneously contract, which ensures the elevation or abduction of the ribs, as well as the diaphragm, which moves towards the abdominal cavity.

As a result, the volume of the chest increases, the pressure in the pleural cavity and in the lungs decreases and, as a result, air from the environment enters the lungs.

The inhaled air contains 20.97% oxygen, 0.03% carbon dioxide and 79% nitrogen.

When exhaling, the expiratory muscles simultaneously contract, which ensures that the ribs return to their pre-inhalation position.

The diaphragm returns to its pre-inhalation position. At the same time, the volume of the chest decreases, the pressure in the pleural cavity and in the lungs increases, and part of the alveolar air is displaced. Exhaled air contains 16% oxygen, 4% carbon dioxide, 79% nitrogen.

In animals, there are three types of breathing: costal, or chest, - when inhaling, abduction of the ribs to the sides and forward predominates; diaphragmatic, or abdominal, - inhalation occurs mainly due to contraction of the diaphragm; costabdominal - inhalation due to contraction of the intercostal muscles, diaphragm and abdominal muscles.

Exchange of gases between alveolar air and blood gases.

The exchange of gases in the lungs between the alveolar air and the blood of the capillaries of the pulmonary circulation occurs due to the difference in the partial pressure of these gases. The oxygen concentration in the alveolar air is much higher than in the venous blood moving through the capillaries. Oxygen, due to the difference in partial pressure according to the law of diffusion, easily passes from the alveoli into the blood, enriching it.

The blood becomes arterial. The concentration of carbon dioxide is much higher in venous blood than in alveolar air.

Carbon dioxide, due to the difference in its voltage in the blood and its partial pressure in the alveolar air, according to the law of diffusion, penetrates from the blood into the alveoli. The composition of alveolar air is constant: about 14.5% oxygen and 5.5% carbon dioxide.

Gas exchange in the lungs is facilitated by the large surface of the alveoli and a thin layer of membrane from the endothelial cells of the capillaries and squamous alveolar epithelium, separating the gas environment and the blood.

During the day, about 5000 liters of oxygen passes from the alveoli into the blood of a cow, and about 4300 liters of carbon dioxide enters the alveolar air from the blood.

Transport of gases by blood.

Oxygen, having penetrated the blood, combines with the hemoglobin of red blood cells and is transported in the form of oxyhemoglobin by arterial blood to the tissues. Arterial blood contains 16...19 volume percent oxygen and 52...57 vol. % carbon dioxide.

Carbon dioxide moves from tissues into the blood, plasma and then into red blood cells.

Animals Respiratory organs and gas exchange Respiration n

Part of it forms a chemical compound with hemoglobin - carbohemoglobin, and the other, under the action of the enzyme carbonic anhydrase, which is contained in erythrocytes, forms a compound - carbonic acid, which quickly dissociates into H+ and HCO3 ions. From the erythrocytes, HCO3~ enters the blood plasma, where it combines with NaCl or KC1, forming carbonic acid salts: NaHC03, KHC03.

About 2.5 vol. % CO2 is in the plasma in a state of physical dissolution. In the form of these compounds, carbon dioxide is transported by venous blood from tissues to the lungs.

Venous blood contains 58...63 vol. % carbon dioxide and 12 vol. % oxygen.

Exchange of gases between blood and tissues. In tissues, oxygen is released from a fragile connection with hemoglobin of erythrocytes and, according to the law of diffusion, easily penetrates into cells, since the oxygen concentration in arterial blood is much higher than in tissues. Here, oxygen is used to oxidize organic compounds to form carbon dioxide. The concentration of carbon dioxide in the tissues increases and becomes significantly higher than in the blood flowing to them.

The carbon dioxide voltage is 60 mmHg. Art. in tissues and 40 mm Hg. Art. in arterial blood, therefore, according to the law of diffusion, it passes from tissues to blood. It is saturated with carbon dioxide, i.e. becomes venous.

EXTERNAL INDICATORS OF THE RESPIRATORY SYSTEM

The activity of the respiratory system is characterized by certain external indicators.

Respiratory rate per 1 min.

For a horse it is 8...16, for cattle - 10...30, for sheep - 10...20, for pigs - 8...18, for rabbits - 15...30, for dogs - 10...30, for cats - 20...30, for birds - 18... 34, and a person has 12...18 movements per minute. Four primary pulmonary volumes: tidal, inspiratory reserve, expiratory reserve, residual volume.

Accordingly, cattle and horses have approximately 5...6 l, 12...18,10...12, Yu...12 l. Four lung capacities: total, vital, inspiratory, functional residual. Minute volume. In cattle - 21...30 l and horses - 40...60 l. Content of oxygen and carbon dioxide in exhaled air.

The tension of oxygen and carbon dioxide in the blood.

REGULATION OF BREATHING

The regulation of breathing is understood as maintaining the optimal content of oxygen and carbon dioxide in the alveolar air and in the blood by changing the frequency and depth of respiratory movements. The frequency and depth of respiratory movements are determined by the rhythm and strength of impulse generation in the respiratory center located in the medulla oblongata, depending on its excitability.

Excitability is determined by the tension of carbon dioxide in the blood and the flow of impulses from the receptor zones of blood vessels, respiratory tract, and muscles.

Regulation of respiratory rate. Regulation of the frequency of respiratory movements is carried out by the respiratory center, which includes the centers of inhalation, exhalation and pneumotaxis; the center of inhalation plays the main role. In the center of inhalation, impulses are generated in rhythmic bursts per unit time, determining the breathing frequency.

Impulses from the center of inspiration arrive to the inspiratory muscles and the diaphragm, causing an inhalation of such duration and depth that corresponds to the prevailing conditions and is characterized by a certain volume of air entering the lungs and the force of contraction of the inspiratory muscles. The number of impulses generated in the center of inspiration per unit time depends on its excitability: the higher the excitability, the more often the impulses are born, and therefore the more frequent the respiratory movements.

Regulation of the change between inhalation and exhalation, exhalation and inhalation.

Regulation of the change from inhalation to exhalation and exhalation to inhalation is carried out reflexively. The excitation that occurs in the center of inspiration ensures the act of inhalation, which is accompanied by stretching of the lungs and excitation of the mechanoreceptors of the pulmonary alveoli. Impulses from the receptors along the afferent fibers of the vagus nerves arrive at the center of exhalation and excite its neurons.

At the same time, directly through the center of pneumotaxy, the inhalation center also excites the exhalation center. The neurons of the exhalation center, being excited, according to the laws of reciprocal relationships, inhibit the activity of the neurons of the inhalation center, and inhalation stops. The exhalation center sends information to the expiratory muscles, causes them to contract, and the act of exhalation occurs.

This is how the alternation of inhalation and exhalation occurs. The number of volleys of impulses coming from the inhalation center per unit time and the strength of these volleys depend on the excitability of the neurons of the respiratory center, the specifics of metabolism, the special sensitivity of neurons to the humoral environment surrounding them, to incoming information from chemoreceptors of blood vessels, respiratory tracts and lungs, muscles and digestive apparatus.

An excess of carbon dioxide in the blood and alveolar air and a lack of oxygen, increased oxygen consumption and the formation of carbon dioxide in muscles and other organs with increased activity cause the following reactions: increased excitability of the respiratory center, increased frequency of birth of impulses in the center of inspiration, increased breathing and, as consequence, restoration of the optimal content of oxygen and carbon dioxide in the alveolar air and blood.

Conversely, excess oxygen in the blood and alveolar air leads to a decrease in respiratory movements and a decrease in ventilation of the lungs. Due to adaptation to changed conditions, the number of respiratory movements in animals can increase by 4...5 times, the tidal volume of air by 4...8 times, and the minute volume of breathing by 10...25 times.

FEATURES OF THE RESPIRATORY SYSTEM IN BIRDS

Unlike mammals, the respiratory system of birds has structural and functional features.

Structural features. The nasal openings in birds are located at the base of the beak; The nasal air passages are short.

Under the external nostril there is a scaly, fixed nasal valve, and around the nostrils there is a corolla of feathers that protects the nasal passages from dust and water. In waterfowl, the nostrils are surrounded by a waxy skin.

Birds lack an epiglottis. The function of the epiglottis is performed by the back of the tongue. There are two larynxes - upper and lower. There are no vocal cords in the upper larynx.

The lower larynx is located at the end of the trachea at the point where it branches into the bronchi and serves as a sound resonator. It has special membranes and special muscles. Air passing through the lower larynx causes the membrane to vibrate, resulting in sounds of different pitches. These sounds are amplified in the resonator. Chickens are capable of making 25 different sounds, each of which reflects a particular emotional state.

The trachea in birds is long and has up to 200 tracheal rings.

Behind the lower larynx, the trachea divides into two main bronchi, which enter the right and left lungs. The bronchi pass through the lungs and expand into the abdominal air sacs. Inside each lung, the bronchi give rise to secondary bronchi, which go in two directions - to the ventral surface of the lungs and to the dorsal one.

The ecto- and endobronchi are divided into a large number of small tubes - parabronchi and bronchioles, and the latter already pass into many alveoli.

Parabronchi, bronchioles and alveoli form the respiratory parenchyma of the lungs - the “arachnoid network”, where gas exchange takes place.

The lungs are elongated, low-elastic, pressed between the ribs and firmly connected to them. Since they are attached to the dorsal wall of the chest, they cannot expand like the lungs of mammals, which are free in the chest.

The lung weight of chickens is approximately 30 g.

Birds have the rudiments of two diaphragm lobes: pulmonary and thoracoabdominal. The diaphragm is attached to the spinal column by tendons and small muscle fibers to the ribs. It contracts in connection with inhalation, but its role in the mechanism of inhalation and exhalation is insignificant. In chickens, the abdominal muscles play a large part in the act of inhalation and exhalation.

The respiration of birds is associated with the activity of large air sacs, which are combined with the lungs and pneumatic bones.

Birds have 9 main air sacs - 4 paired, located symmetrically on both sides, and one unpaired.

The largest are the abdominal air sacs. In addition to these air sacs, there are also air sacs located near the tail, the posterior trunk, or intermediate.

Air sacs are thin-walled formations filled with air; their mucous membrane is lined with ciliated epithelium. From some air sacs there are processes leading to bones that have air cavities. There is a network of capillaries in the wall of the air sacs.

Air sacs perform a number of roles:

1) participate in gas exchange;

2) lighten body weight;

3) ensure normal body position during flight;

4) help cool the body during flight;

5) serve as an air reservoir;

6) act as a shock absorber for internal organs.

Pneumatic bones in birds are the cervical and dorsal bones, caudal vertebrae, humerus, thoracic and sacral bones, and the vertebral ends of the ribs.

The lung capacity of chickens is 13 cm3, ducks - 20 cm3, the total capacity of the lungs and air sacs is 160...170 cm3, respectively, 315 cm3, 12...15% of it is the tidal volume of air.

Functional features.

Birds, like insects, exhale when the respiratory muscles contract; In mammals, the opposite is true - when the inspiratory muscles contract, they inhale.

Birds have relatively frequent breathing: chickens - 18...25 times per minute, ducks - 20...40, geese - 20...40, turkeys - 15...20 times per minute. The respiratory system in birds has great functionality - under load, the number of respiratory movements can increase: in farm birds up to 200 times per minute.

The air entering the body during inhalation fills the lungs and air sacs.

Air spaces are actually reserve containers for fresh air. In the air sacs, due to the small number of blood vessels, oxygen absorption is negligible; In general, the air in the bags is saturated with oxygen.

In birds, the so-called double gas exchange occurs in the lung tissue, which occurs during inhalation and exhalation. Due to this, inhalation and exhalation are accompanied by the extraction of oxygen from the air and the release of carbon dioxide.

In general, breathing in birds occurs as follows.

The muscles of the chest wall contract so that the sternum is raised.

This means that the chest cavity becomes smaller and the lungs are compressed to the point that carbon dioxide-laden air is forced out of the breathing chambers.

As air leaves the lungs during exhalation, new air from the air spaces moves forward through the lungs. When you exhale, air passes predominantly through the ventral bronchi.

After the muscles of the chest have contracted, exhalation has taken place and all used air has been removed, the muscles relax, the sternum moves down, the chest cavity expands, becomes large, a difference in air pressure is created between the external environment and the lungs, and inhalation is carried out.

It is accompanied by air movement mainly through the dorsal bronchi.

The air sacs are elastic, like the lungs, so when the chest cavity expands, they also expand.

The elasticity of the air sacs and lungs allows air to enter the respiratory system.

Since muscle relaxation causes air to enter the lungs from the environment, the lungs of a dead bird, whose breathing muscles are normally relaxed, will be distended, or filled with air.

In dead mammals they are asleep.

Some diving birds can remain underwater for a significant period of time, during which air circulates between the lungs and air sacs, and most of the oxygen passes into the blood, maintaining an optimal oxygen concentration.

Birds are very sensitive to carbon dioxide and react differently to increases in its content in the air.

The maximum permissible increase is no more than 0.2%. Exceeding this level causes inhibition of respiration, which is accompanied by hypoxia - a decrease in the oxygen content in the blood, while the productivity and natural resistance of birds decreases. In flight, breathing is reduced due to improved ventilation of the lungs even at an altitude of 3000...400 m: in conditions of low oxygen content, birds provide themselves with oxygen by breathing rarely. On the ground, birds die under these conditions.

Breathing and circulation of animals

Animals get the oxygen they need from the atmosphere or water in which it is dissolved. Therefore, their respiratory organs are diverse. The connection between the respiratory organs and all tissues of the body is ensured by the circulatory system.

Respiratory functions

As a result of respiration in animals, like in plants, gas exchange occurs: oxygen enters the body, and carbon dioxide is removed from the body.

In unicellular animals (amoeba, ciliates) and simple multicellular animals (many worms), gas exchange occurs through the integument of the body.

Animal respiratory system

Most multicellular animals have a need to transport oxygen to cells located far from the integument. It is provided by the respiratory organs and circulatory system. Blood serves as a carrier of oxygen and carbon dioxide. It delivers oxygen to all cells of the animal’s body and frees them from carbon dioxide formed during the “work” of the cells.

Animal respiratory organs

The respiratory organs of animals are very diverse.

Gills arose in aquatic animals as derivatives of the pharynx in the form of skin outgrowths on both sides of the body. The gills of fish are located under the gill covers and consist of gill arches with gill filaments. They are abundantly permeated with tiny blood vessels, through the walls of which gas exchange occurs.

The respiratory organs of terrestrial animals are the trachea and lungs. Insect tracheas are thin tubes through which air oxygen is delivered to all internal organs.

The openings of the trachea - spiracles - are usually located on the abdomen of the insect. When the abdominal muscles contract, air is pushed out of the trachea, and when they relax, it enters the body.

The lungs are the respiratory organs of terrestrial vertebrates.

In frogs they are hollow sacs. In the lungs of crocodiles, turtles, and snakes there are partitions that increase their surface area. The lungs of birds and mammals consist of thin-walled pulmonary vesicles. The walls of the vesicles are penetrated by small blood vessels. Thanks to this structure of the lungs, the gas exchange surface increases many times.

Circulation circles

The blood of animals with lungs passes through two circles of blood circulation: small and large.

Through the pulmonary circulation, blood flows from the heart to the lungs. Gas exchange takes place in the lungs, the blood is saturated with oxygen and enters the heart. This oxygenated blood then flows through the systemic circulation to all organs and tissues, and from them back to the heart.

What respiratory organs do animals have?

Respiratory system of mammals comprises lungs, which have a large respiratory surface and alveolar structure.

Respiratory surface of the lungs in some species of mammals it exceeds the surface of their body by 50 times or more. Breathing mechanism caused by a signal from the brain, after which they expand intercostal muscles And diaphragm and air is inhaled, followed by exhalation.

Mammalian circulatory system has similarities with the circulatory system of birds. Mammals also have four chamber heart, but in mammals the left aortic arch departs from the left ventricle. Also, due to the presence in the blood hemoglobin(a respiratory pigment found in blood cells, red blood cells), the blood of mammals has a greater oxygen capacity than the blood of birds.

Due to high activity and the release of great heat as a result of processes taking place in the body of mammals, mammals have a constant high body temperature.

What animals breathe with the help of their lungs you will learn in this article.

What animals breathe with their lungs?

Lungsbreathe -terrestrial vertebrates(amphibians, reptiles, birds, animals)

Animals and birds breathe with lungs, which are structured approximately the same as those of humans.

But marine mammals have lungs, but despite this, they can stay under water for a very long time. For example, a sperm whale can descend to a depth of about 1000 meters and remain under water for 1 hour, because its giant lungs are capable of storing 1000 liters of air. Just like a whale, when it breathes, it expels air and water vapor through its nasal opening, which condenses in the cold - the result is a huge fountain 4 to 5 meters high.

In the lungs, gas exchange occurs between the air in the lung parenchyma and the blood flowing through the pulmonary capillaries.

The lungs are also called the respiratory organs of some invertebrate animals (some mollusks, sea cucumbers, arachnids).

During inhalation, air containing oxygen enters the lungs. The lungs look like cellular sacs. In each lung (left and right), the bronchi branch very strongly, which end in numerous pulmonary vesicles. Each pulmonary vesicle is surrounded by a network of blood vessels. From the pulmonary vesicle, oxygen from the air passes into the blood, and carbon dioxide from the blood into the air. After carbon dioxide accumulates in the pulmonary vesicle, exhalation occurs. The cellular structure of the lungs makes it possible to increase their internal surface many times over.

Primitive gills are found in. In most higher animals, these are located on the lateral walls of the body and the upper parts of the thoracic legs. Aquatic insect larvae have tracheal gills, which are thin-walled outgrowths on different parts of the body in which there is a network of tracheae.

Of the echinoderms, starfish and sea urchins have gills. All proto-aquatic chordates (fish) have rows of paired openings (gill slits) located in the pharynx. In enterophores (mobile bottom-dwelling animals), tunicates (small marine animals with a sac-like body covered with a membrane) and anuranids (a special group of invertebrate animals), gas exchange occurs during the passage of water through the gill slits.

How animals breathe with gills

The gills consist of leaflets (threads), inside them there is a network of blood vessels. The blood in them is separated from the external environment by a very thin skin, and the necessary conditions are created for the exchange between gases dissolved in water and the blood. The gill slits in fish are divided by arches, from which branchial septa extend. In some bony and cartilaginous species, the petals of the gills are located on the outer side of the arches in two rows. Actively swimming fish have gills with a much larger surface area than sedentary aquatic animals.

In many invertebrates and young tadpoles, these respiratory organs are located on the outside of the body. In fish and higher crustaceans they are hidden under protective devices. Often the gills are located in special body cavities; they can be covered with special folds of skin or leathery covers (gill operculum) to protect them from damage.

The gills also function as a circulatory system.

The movement of the gill cover during breathing occurs simultaneously with the movement (opening and closing) of the mouth. When breathing, the fish opens its mouth, draws water in, and closes its mouth. Water affects the respiratory organs, passes through them and comes out. Oxygen is absorbed by the capillaries of the blood vessels located in the gills, and the used carbon dioxide is released through them into the water.