Animals symbol of belly breathing. What animals breathe with their lungs? Questions for self-control
“Structure and functions of the respiratory organs” - Participate in voice formation. Nasal cavity. Transport of gases by blood. External breathing. Air. Functions of the respiratory organs. Structure of the larynx. Larynx. Sound formation. Trachea and bronchi. Internal breathing. Breath. The structure and significance of the respiratory system. Nasal turbinates.
“Breathing gymnastics” - Let’s throw the ball. Breathing exercises will strengthen the baby's immunity. Hen. An invaluable contribution to his health. Little engine. Why is breathing exercise necessary? Blow up the balloon. Breathing exercises for children preschool age. Trumpeter. Breathing exercises. Grow big. Exhaling slowly helps you relax and calm down. Cockerel. Breathing exercises. Breathing exercises can be used in various routine moments.
“Human respiratory organs” - Functions of the nasal cavity. A person cannot help but breathe. The meaning of breathing. Air. Breath. Respiratory system. Animals breathe through their lungs. Trachea. The main organ of the respiratory system is the lungs. Smoking. Breathing is extremely important for a person. You need to breathe not through your mouth, but through your nose. People are cutting away the basis of their existence. Correct breathing. Air gates to the body. Smoke particles. Nicotine. It passes through the nose into the chest.
“Correct breathing” - Human respiratory system. Take a position lying on your back. Payback for improper breathing. Correct breathing. Breathing rhythm assessment. Abdominal breathing exercise. Assessment of breathing habits. Recommendations. Alternating abdominal and thoracic breathing. Chinese proverb. A person is born with the correct breathing mechanism. There are three types of breathing. Respiratory muscles. Determination of breathing depth.
“Structure of the respiratory system” - Upper respiratory tract. A tube. Transport of gases. External breathing. The processes of inhalation and exhalation. Sneezing. Diffusion of gases. Inhalation mechanism. Vocal cords. Gas exchange in the lungs. Gas exchange in tissues. The mechanism of inhalation and exhalation. Respiratory system. Respiratory system. Meaning of the larynx. Tissue cells. Label. Alveoli. The structure of the lungs. Airways. Human voice. Trachea. Exhalation mechanism. A set of physiological processes.
“Respiratory system” - Gas exchange in the lungs and tissues. Experience. Transfer of gases. "While I breathe I hope". Changes in the composition of inhaled and exhaled air. The meaning of breathing. Breathing in the mountains. Composition of inhaled and exhaled air. Organs of the respiratory system. Give reasons for your statement. The structure of the lungs.
Which animal can breathe in three different ways?
The largest order of amphibians, numbering over 4 thousand species, has this amazing opportunity. Usually the concept of a frog refers specifically to this group of animals as a whole, although its use as a designation of a taxonomic group is incorrect due to the vagueness of the traditions of use.
These amphibians have a unique feature among vertebrates - an independently living larval stage. In most of them, from the young individual that is born, an adult animal eventually appears, in which the larvae are a completely different creature from the parents.
This is especially pronounced in the larvae of tailless amphibians - tadpoles. They breathe through gills, while adults breathe through their skin and lungs. They have a tail with which they swim; adults do not have a tail.
Metamorphosis of a frog: 1 - eggs (spawn), 2 - tadpole with external gills, 3 - without gills, 4 - with hind legs, 5 - with all legs and a tail, 6 - frog.
After such a metamorphosis, the frog breathes atmospheric air. The lungs and skin are used for breathing. The lungs look like bags. Their walls contain a large number of blood vessels in which gas exchange occurs. The frog's throat is pulled down several times per second, creating a rarefied space in the oral cavity. Then the air penetrates through the nostrils into the oral cavity, and from there into the lungs. It is pushed back under the action of the muscles of the body walls. The frog's lungs are poorly developed, and skin respiration is as important for it as pulmonary respiration. Gas exchange is possible only when the skin is wet. If a frog is placed in a dry vessel, its skin will soon dry out and the animal may die. Immersed in water, the frog completely switches to skin respiration.
The meaning of breathing.Breathing is a vital process of constant exchange of gases between the body and its surrounding environment.
Impossible without oxygen oxidative processes, underlying metabolism, and to preserve life, its constant intake into the body is necessary. Oxygen enters the blood through the respiratory organs and is delivered to the organs and tissues by the blood. Carbon dioxide is produced in cells and tissues as a result of metabolism. It is carried by the blood to the respiratory organs and removed from the body.
Evolution of the respiratory system. As the organization of animals became more complex, various systems of respiratory organs arose. Despite the appearance of such specialized organs, many animals retain the cutaneous type of respiration, that is, gas exchange through the surface of the body. It is well expressed in many embryos and larvae. In insect larvae with a tracheal system, about 25% of oxygen is absorbed through the skin. Skin respiration is also observed in fish. can live for a long time after removal of both lungs, but dies if skin breathing is also excluded after the operation. The participation of the skin in the respiration of the frog can be judged by the fact that it can be easily put to sleep by applying a cotton swab with ether to the skin of the abdomen. In higher vertebrates and humans, cutaneous respiration is not essential in connection with the development of the lungs. However, it was possible to notice that in a horse with increased muscle load, breathing through the skin intensifies.
They have a very special system for delivering oxygen to cells. In each segment of the body there is a pair of holes called spiracles, from which tracheas go into the body - tubes that branch repeatedly and connect to all cells of the body. The body walls of insects pulsate, drawing air into the trachea as the body expands and squeezing it out as it contracts. In insects, the tracheal system conducts air deep into the body, bringing it so close to each cell that it can diffuse into it through the walls of the smallest branches of the trachea.
Respiration in most aquatic animals is carried out using gills. , mollusks, many arthropods (shrimp, crabs) have gills. Every animal with gills has one or another device that allows them to be washed with water. In fish, water enters the mouth, passes over the gills and exits through the gill slits. The gills have thin walls, a large surface and are abundantly supplied with blood capillaries. Oxygen dissolved in water; diffuses through the gill epithelium into the capillaries, and carbon dioxide diffuses in the opposite direction. In stagnant bodies of water, where there is little oxygen dissolved in the water, fish suffocate.
Animal lungs have passed a long way development. We find the first hint of lungs in some fossil fish. They developed a growth at the anterior end of the digestive tract; this growth subsequently developed into a lung. In some fish, the outgrowth has turned into a swim bladder, which sometimes also has a respiratory function. The swim bladder contains cells that are capable of releasing oxygen obtained from the blood into the internal cavity. Another group of swim bladder cells carries oxygen from the swim bladder to the blood.
The lungs of most primitives are two simple long bags, covered on the outside with capillaries. Frogs and toads have folds inside the pulmonary sac that increase the respiratory surface. Frogs have neither a diaphragm nor respiratory muscles. Because of this, they have a special breathing mechanism. It is based on the action of valves in the nostrils and muscles in the floor of the mouth. When the nasal valves are open, the floor of the mouth lowers and air enters. Then the nasal valves close and the throat muscles contract, forcing air into the lungs. A frog cannot breathe with its mouth open.
Further evolution of the respiratory organs occurred in the direction of gradual division of the lung into smaller and smaller cavities. The lungs of some lizards () are equipped with accessory air sacs that can fill with air, while the animal swells and scares away predators.
In birds of this kind, bags extend from the lungs in several places and spread throughout the body. The lungs reached their greatest development in warm-blooded animals. The abundance of pulmonary vesicles and their cellular structure provide a large surface area through which intense gas exchange occurs. In a horse, the respiratory surface of the lungs is 500 m2.
Breathing movements. Thanks to the rhythmically occurring acts of inhalation and exhalation, an exchange occurs between atmospheric and alveolar air located in the pulmonary vesicles.
The lungs have no muscle tissue and therefore cannot actively contract or relax. The skeletal respiratory muscles play an active role in the act of inhalation and exhalation. When the respiratory muscles are paralyzed, breathing becomes impossible, although the respiratory organs are not affected.
When inhaling, the external intercostal muscles and the diaphragm contract. The intercostal muscles lift the ribs and move them slightly to the side. The volume of the chest cavity increases. The lowering of the diaphragm causes the volume of the chest to increase in length. When breathing deeply, other muscles of the chest and neck are also involved.
The lungs are covered on the outside with a thin film of connective tissue - the pulmonary pleura. The inner wall of the chest cavity is lined with parietal pleura. The narrow gap between them is sealed, that is, it has no communication with the surrounding air, and is filled with pleural fluid, which reduces the friction of the lungs against the walls of the chest cavity during breathing. Since the lung is in a distended state in the chest, the pressure in the pleural cavity is lower than atmospheric, that is, negative. Due to the negative pressure in the pleural cavity, the lungs follow the chest. The lungs are stretched. In a distended lung, the pressure decreases, and due to the pressure difference, atmospheric air rushes through the respiratory tract into the lungs. The more the volume of the chest increases during inhalation, the more the lungs stretch, the deeper the inhalation.
When the respiratory muscles relax, the ribs lower to their original position, the dome of the diaphragm rises, the volume of the chest, and therefore the lungs, decreases and the air is exhaled out. The abdominal muscles, internal intercostal and other muscles take part in deep exhalation. Frequency and amount of breathing. The respiratory rate varies among different animals and is related to the metabolic rate. It increases with an increase in external temperature, increased physical activity, and illness of the animal.
The amount of air that an animal inhales during quiet breathing is called respiratory air. In a horse or cow it is 5-6 liters. The respiration rate is the amount of air inhaled within 1 minute. It varies depending on the intensity of work, feeding and other factors. Horses have a breathing volume of 40-50 liters at rest, 80-90 liters when moving, and 400-450 liters when transporting heavy objects.
Gas exchange in the lungs and tissues. To understand the mechanism of gas exchange in the lungs and tissues, let us compare the composition of inhaled, exhaled and alveolar air. Composition of inhaled, exhaled and alveolar air. By alternately inhaling and exhaling, the animal ventilates the lungs, maintaining a relatively constant gas composition in the pulmonary vesicles (alveoli). Animals breathe atmospheric air with a high oxygen content (20.9%) and a low oxygen content carbon dioxide(0.03%), and they exhale air in which there is 16.3% oxygen and about 4% carbon dioxide.
The composition of alveolar air differs significantly from the composition of atmospheric, inhaled air. It contains significantly less oxygen (14.2%) and a large amount of carbon dioxide (5.2%).
Nitrogen, which is part of the air, does not take part in respiration, and its content in inhaled, exhaled and alveolar air practically does not change.
Why does exhaled air contain more oxygen than alveolar air? This is explained by the fact that when you exhale, air that is in the respiratory organs, in the airways, is mixed with the alveolar air.
Partial pressure and tension of gases. In the lungs, oxygen from the alveolar air passes into the blood, and carbon dioxide from the blood enters the lungs. The transition of gases from air to liquid and from liquid to air occurs due to the difference in the partial pressure of these gases in air and liquid. Partial pressure is the part of the total pressure that accounts for the share of a given gas in a gas mixture. The higher the percentage of gas in the mixture, the correspondingly higher its partial pressure. Atmospheric air, as is known, is a mixture of gases. This mixture of oxygen gases contains 20.94% oxygen, 0.03% carbon dioxide and 79-.03% nitrogen. This mixture of atmospheric gases has a pressure of 760 mm Hg. Art. Partial pressure of oxygen in atmospheric air is 20.94% of 760 mmHg. Art., i.e. 159 mm Hg. Art., nitrogen - 79.03% of 760 mm Hg. Art., i.e. about 600 mm Hg. Art., there is little carbon dioxide in the atmospheric air - 0.03%, therefore its partial pressure is 0.03% of 760 mm Hg. Art. - 0.2 mm Hg. Art.
For gases dissolved in a liquid, the term voltage is used, corresponding to the term partial pressure for free gases. Pelvic tension is expressed in the same units as pressure (mmHg). If the partial pressure of a gas in the environment is higher than the voltage of that gas in the liquid, then the gas dissolves in the liquid.
The partial pressure of oxygen in the alveolar air is 100-110 mm Hg. Art., and in the blood flowing to the lungs the oxygen tension is on average 60 mm Hg. Art., therefore, in the lungs, oxygen from the alveolar air passes into the blood. The movement of gases occurs according to the laws of diffusion, according to which gas spreads from an environment where the partial pressure is high to an environment with lower pressure.
The purpose of the lesson: show the diversity of respiratory organs in animals. Find out the importance of breathing.
Lesson objectives.
- Continue developing the ability to recognize organs and organ systems of animals in pictures and tables.
- Strengthen the skills of independent knowledge search.
- Continue developing skills in group activities and working with new information.
- Create conditions for the development of the emotional field of students’ personality, the ability to defend their own opinion.
Equipment.
Tables: “Type Protozoa”, “Type Coelenterates”, “Type Arthropods. Class Insects. Class Arachnids. Class Crustaceans (internal structure of cancer)”, “Type Chordata. Internal structure of fish. Internal structure of a frog. Internal structure of a bird. The internal structure of a dog.” Textbook drawings (pp. 68-71).
Didactic material: Didactic material “Biological labyrinths”, correct answer key.
Basic concepts and terms. Spiracles, trachea, external gills, internal gills, lungs, pulmonary sacs. Cellular respiration, respiration through the entire surface of the body, cutaneous respiration, pulmonary respiration.
Lesson type: combined.
I. Organizing time(5 minutes)
Hello, dear guys. At the beginning of the lesson, as always, we write down our homework. (Write from the board in the diary). Page 68–71. Page 73 (test your knowledge). Questions 1-6.
We continue to study the topic “Breathing”. In the last lesson we found out the significance of this process for plants. Today we will talk about animals.
Guys, what do you think, do all living creatures on Earth breathe the same way as plants, that is, they absorb oxygen and release carbon dioxide?
Students suggest their own answer options.
The purpose of today's lesson will be to clarify the importance of respiration and the structure of the respiratory organs in animals.
Recording the output of the lesson on the board: “Respiration in animals.”
II. Learning new material
1. Students are divided into groups to work on the information sheets. (The division can be carried out by desks, by choosing sheets of paper with a certain color, etc.)
The first microgroup receives information sheet 1 and the table “Type Protozoa”, Type “Coelenterates”.
Information sheet 1. (Textbook page 68)
Type of respiration: cellular.
Organisms: unicellular animals (amoeba, green euglena, ciliates slipper); coelenterates (jellyfish, coral polyps); some worms.
Respiration mechanism: Unicellular organisms and some multicellular organisms (type Coelenterates, type Annelids...) absorb oxygen dissolved in water over the entire surface of the body .
Oxygen is involved in the breakdown of complex organic substances, resulting in the release of energy that is necessary for the life of the animal.
The carbon dioxide produced as a result of respiration is also released through the entire surface of the body.
Speaker's response as planned.
- Type of breathing.
The second microgroup works with information sheet 2 and the table “Type Arthropods. Class Insects.”
Information sheet 2. (Textbook page 68)
Type of breathing: tracheal.
Organisms: class Insects (beetles, butterflies, grasshoppers, flies).
Breathing mechanism.
The insect's abdomen is divided into 5–11 parts (segments). Each of them has a pair of small holes - spiracles . Branching tubes extend inward from each spiracle - trachea , which permeate the entire body of the insect. Watching the cockchafer, you can notice how its abdomen either decreases in volume or increases in size. These are breathing movements. When you inhale, air containing oxygen enters the body through the spiracles, and when you exhale, air saturated with carbon dioxide comes out.
Speaker's response as planned.
- Type of breathing.
- What organisms is it typical for?
- How does the breathing process occur?
The third microgroup works with information sheet 3 and the table “Type Chordates. Pisces class. Internal structure of fish”, “Type Arthropods. Internal structure of cancer"
Information sheet 3. (Textbook page 70)
Type of breathing: gill.
Organisms: many aquatic inhabitants (fish, crayfish, mollusks).
Breathing mechanism.
Fish breathe oxygen dissolved in water using special branched skin projections called gills. Fish constantly swallow water. From the oral cavity, water passes through the gill slits, washes the gills and comes out from under the gill covers. The gills consist of gill arches and gill filaments, which are penetrated by many blood vessels. From the water that washes the gills, oxygen enters the blood, and carbon dioxide is removed from the blood into the water. The gills found inside the body are called internal gills.
Speaker's response as planned.
- Type of breathing.
- What organisms is it typical for?
- How does the breathing process occur?
The fourth microgroup receives information sheet 4 and the table “Type Chordates. Class Amphibians”
Information sheet 4.
Type of breathing: cutaneous.
Organisms: amphibians (salamanders, frogs...).
Breathing mechanism.
The lungs of amphibians are poorly developed, so additional gas exchange occurs through moist skin. The thin skin of amphibians contains many glands that secrete mucus. Thanks to mucus, a liquid film is created on the surface of the skin, in which atmospheric oxygen dissolves and, thanks to which, breathing through the skin is possible.
Pulmonary and skin respiration in amphibians are not equally developed. Those of them who spend most of their lives in water have less developed lungs and better skin respiration. Amphibians living far from bodies of water have more developed lungs and less developed skin respiration.
Speaker's response as planned.
- Type of breathing.
- What organisms is it typical for?
- How does the breathing process occur?
The fifth microgroup receives information sheet 4 and tables “Type Chordata. Class Reptiles. Bird class. Class Mammals.
Information sheet 5. (Textbook page 71)
Type of breathing: pulmonary.
Organisms: terrestrial vertebrates (amphibians, reptiles, birds, mammals, humans)
Breathing mechanism.
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.
Speaker's response as planned.
- Type of breathing.
- What organisms is it typical for?
- How does the breathing process occur?
2. Protecting group work
The information is presented by the group speaker according to the plan, using a visual aid. The second student at the board writes down the data in the table (students also fill out the table in notebooks, thereby beginning to draw up a supporting summary of the topic). After defending the group work, a supporting summary of the topic appears on the board and in notebooks.
Breathing in animals
| Breathing type | Organs of breathing | Organisms for which this is typical |
| 1. Cellular | Whole body surface | Unicellular organisms, coelenterates, some worms |
| 2. Tracheal | Spiracles, trachea | Insects |
| 3. Gill | Gills | Fish, crustaceans, molluscs |
| 4. Skin | Leather | Amphibians |
| 5. Pulmonary | Lungs | Terrestrial vertebrates |
III. Physical education moment
Exercises to relax the muscles of the limbs, gymnastics for the eyes.
IV. Reinforcing the material learned
1. After filling out the table, children once again name the types of breathing, respiratory organs and organisms for which this is typical. (No more than 1 min.)
2. Completing the task: Go through the maze. (Students are familiar with this form of work. For each child there is a different version of the labyrinth and an instruction card for it on the table. (Appendix 1, Appendix 2)
Correct answers to the maze:
1 option
1-6-11-12-13-8-9-15-20
Option 2
ikchivechech (lentils)
- 1 mistake – score “4”;
- 2–3 mistakes – score “3”;
- 4 or more – score “2”.
They grade each other and submit their work to the teacher.
V. Lesson summary
Guys, what did we learn in class today?
The importance of breathing for living organisms, features of the respiratory systems in different animals.
Who can say what breathing is?
- Breath - the process of absorbing oxygen and releasing carbon dioxide and water, as well as energy that ensures the life of the body.
Each of you received a grade for completing the test task. You also receive grades for your work in class... (the most active guys are evaluated).
VI. Reflection
Students say what they liked about the lesson and what was most interesting. When leaving the office, they attach leaves expressing their mood to a piece of Whatman paper with a drawn tree.
Red leaf – great mood, I liked everything.
Green leaf – the mood is so-so, not bad.
Yellow sheet - bad mood, didn’t like the lesson.
This information is for the teacher to reflect on the lesson.
Literature
- Sonin N.I. Biology. Living organism grade 6. – M.: Bustard, 2004.
- Sementsova V.N. Biology. Technological maps lessons 6th grade. – S-F: Parity, 2001.
- Batuev A.S., Gulenkova M.A., Elenevsky A.G.
- Biology. Great reference book. – M.: Bustard, 1999.
Morzunova Inna Borisovna. A book for teachers for the textbook by N.I. Sonin Biology. Living organism grade 6. – M.: Bustard, 2010.
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. Allows air to pass into the lungs from environment
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 inhaling, the volume of the chest increases, the pressure in the pleural cavity decreases and, as a result, air enters from external environment into the lungs. 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 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 erythrocytes, HCO3~ enters the blood plasma, where it combines with NaCl or KC1, forming salts of carbonic acid: NaHC0 3, KHC0 3. About 2.5 vol.% CO2 is in the state of physical dissolution. In the form of these compounds, carbon dioxide is transported from the 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 for oxidation organic compounds with the formation of 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, large cattle- 10...30, sheep - 10...20, pigs - 8...18, rabbits - 15...30, dogs - 10...30, cats - 20...30, 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; belongs to the center of inhalation 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.