A person breathes atmospheric air, which has the following composition: 20.94% oxygen, 0.03% carbon dioxide, 79.03% nitrogen. Exhaled air contains 16.3% oxygen, 4% carbon dioxide, and 79.7% nitrogen.

The composition of exhaled air is not constant and depends on the intensity of metabolism, as well as on the frequency and depth of breathing. As soon as you hold your breath or make several deep breathing movements, the composition of the exhaled air changes.

Comparison of the composition of inhaled and exhaled air serves as evidence of the existence of external respiration.

Alveolar air its composition differs from that of the atmosphere, which is quite natural. In the alveoli, gases are exchanged between air and blood, while oxygen diffuses into the blood, and carbon dioxide diffuses out of the blood. As a result, in the alveolar air the oxygen content sharply decreases and the amount of carbon dioxide increases. The percentage of individual gases in the alveolar air: 14.2-14.6% oxygen, 5.2-5.7% carbon dioxide, 79.7-80% nitrogen. Alveolar air differs in composition from exhaled air. This is explained by the fact that the exhaled air contains a mixture of gases from the alveoli and harmful space.

RESPIRATION CYCLE

The respiratory cycle consists of inhalation, exhalation and a respiratory pause. Usually the inhalation is shorter than the exhalation. The duration of inhalation in an adult is from 0.9 to 4.7 s, the duration of exhalation is 1.2-6 s. The duration of inhalation and exhalation depends mainly on reflex effects coming from the receptors of the lung tissue. The respiratory pause is a variable component of the respiratory cycle. It varies in size and may even be absent.

Respiratory movements occur with a certain rhythm and frequency, which are determined by the number of chest excursions per minute. In an adult, the respiratory rate is 12-18 per minute. In children, breathing is shallow and therefore more frequent than in adults. So, a newborn breathes about 60 times per minute, a 5-year-old child 25 times per minute. At any age, the frequency of respiratory movements is 4-5 times less than the number of heartbeats.
Depth of breathing movements determined by the amplitude of chest excursions and using special methods that allow one to study pulmonary volumes.
The frequency and depth of breathing is influenced by many factors, in particular the emotional state, mental stress, changes in the chemical composition of the blood, the degree of fitness of the body, the level and intensity of metabolism. The more frequent and deeper the breathing movements, the more oxygen enters the lungs and, accordingly, the greater amount of carbon dioxide is eliminated.
Rare and shallow breathing can lead to insufficient oxygen supply to the body's cells and tissues. This in turn is accompanied by a decrease in their functional activity. The frequency and depth of respiratory movements change significantly in pathological conditions, especially in diseases of the respiratory system.

Inhalation mechanism. Inhale ( inspiration) occurs due to an increase in the volume of the chest in three directions - vertical, sagittal(anteroposterior) and frontal(rib). The change in the size of the chest cavity occurs due to contraction of the respiratory muscles.
When the external intercostal muscles contract (during inhalation), the ribs take a more horizontal position, rising upward, while the lower end of the sternum moves forward. Due to the movement of the ribs during inhalation, the dimensions of the chest increase in the transverse and longitudinal directions. As a result of contraction of the diaphragm, its dome flattens and lowers: the abdominal organs are pushed down, to the sides and forward, as a result, the volume of the chest increases in the vertical direction.

Depending on the predominant participation in the act of inhalation, the muscles of the chest and diaphragm are distinguished chest, or costal, and abdominal, or diaphragmatic, type of breathing. In men, the abdominal type of breathing predominates, in women - thoracic.
In some cases, for example, during physical work, during shortness of breath, the so-called auxiliary muscles - the muscles of the shoulder girdle and neck - can take part in the act of inhalation.
When you inhale, the lungs passively follow the expanding chest. The respiratory surface of the lungs increases, pressure same in them goes down and becomes 0.26 kPa (2 mm Hg) below atmospheric. This promotes the flow of air through the airways into the lungs. The glottis prevents rapid equalization of pressure in the lungs, since the airways in this place are narrowed. Only at the height of inspiration does the dilated alveoli become completely filled with air.

Exhalation mechanism. Exhale ( expiration) is carried out as a result relaxing the external intercostal muscles and raising the dome of the diaphragm. In this case, the chest returns to its original position and the respiratory surface of the lungs decreases. The narrowing of the airways in the glottis area causes the slow release of air from the lungs. At the beginning of the exhalation phase, the pressure in the lungs becomes 0.40-0.53 kPa (3-4 mm Hg) higher than atmospheric pressure, which facilitates the release of air from them into the environment.

1) What substances are part of living organisms? 2) What methods exist for studying nature? 3) What is the name of a cluster of stars and constellations? 4) What

the celestial body is called a caudate? 5) The oceans closest to Astana, Almaty, Aktau. The oceans farthest from Astana, Almaty. Aktau. 6) How are color and sound phenomena measured? 7) List 10 nature reserves? 8) List the galaxies 10? 9 ) How much is a complete circle of the earth around its axis? 10) How much is a complete circle of the earth around the sun? 11) List the “most” rivers? 12) What science studies weather? 13) What is the name for the propagation of molecules through the air? plants?15) List the types of communities? you can skip which ones you don’t know and thank you very much in advance, we just have a science exam soon and I really need it and thank you very much again for everything you do

HELP I AM WRITING URGENTLY GIA

AND THIS IS NECESSARY
I WILL GIVE ALL POINTS
1. What formed elements of blood transport oxygen and carbon dioxide?
1) platelets 2) erythrocytes
3) leukocytes 4) lymphocytes
2. How does exhaled air differ in composition from inhaled air?
1) high content of nitrogen, oxygen and carbon dioxide
2) lower content of carbon dioxide and oxygen
and large - nitrogen
3) lower content of nitrogen and oxygen
4) lower oxygen content, higher carbon dioxide content and unchanged nitrogen content
3. What causes gas exchange in the lungs?
1) diffusion 2) active transport
3)passive transport 4)osmosis
4. Where does the systemic circulation begin?
1) right atrium 2) left atrium
3) left ventricle 4) right ventricle
5. . What device is used to determine vital capacity (vital capacity of the lungs)?
4) spirometer
6. What science studies the internal structure of organisms?
1)anatomy 2)physiology
3) genetics 4) cytology
7. The importance of breathing is to provide for the body
1) energy
2) building material
3) reserve nutrients
4) vitamins
8. If a person smokes a lot, then he has
1) the amount of biologically active substances in the pulmonary vesicles increases
2) pulmonary vesicles stick together due to damage
a film of biologically active substances lining them from the inside
3) the ability of hemoglobin to attach oxygen increases
4) pulmonary vesicles lose their elasticity and ability to clear themselves
9. Leads to the release of energy in the body
1) formation of organic compounds
2) diffusion of substances through cell membranes
3) oxidation of organic substances in body cells
4) decomposition of oxyhemoglobin to oxygen and hemoglobin
10. Cigarette smoke contains more than 200 harmful substances,
including carbon monoxide, which
1) reduces the speed of blood movement
2) forms a stable compound with hemoglobin
3) increases blood clotting
4) reduces the body's ability to produce antibodies
11. The role of respiration in the life of organisms is to produce
1) formation and deposition of organic substances
2) absorption of carbon dioxide from the environment
3) freeing the energy necessary for their life activity
4) absorption of organic substances from the environment

12. The air in the respiratory tract is warmed due to the fact that
1) their walls are lined with ciliated epithelium
2) in their walls there are glands that secrete mucus
3) small blood vessels branch in their walls
4) pulmonary vesicles consist of a single layer of cells
13. In case of carbon monoxide poisoning
1) body cells receive less oxygen
2) the vital capacity of the lungs decreases
3) the shape of red blood cells changes
4) the process of nutrient absorption slows down
14. The vital capacity of the lungs in an adult healthy person ranges from
1)1 up to 2 l 2)6 up to 7 l 3)3 up to 5 l 4)7 up to 8 l
15. What kind of blood flows in the veins of the systemic circulation in mammals and humans?
1) saturated with carbon dioxide 2) saturated with oxygen
3) arterial 4) mixed

Atmospheric air entering the lungs during inhalation is called inhaled by air; air released through the respiratory tract during exhalation - exhaled. Exhaled air is a mixture of air filling out alveoli, - alveolar air- with air located in the airways (in the nasal cavity, larynx, trachea and bronchi). The composition of inhaled, exhaled and alveolar air under normal conditions in a healthy person is quite constant and is determined by the following figures (Table 3).

These figures may fluctuate somewhat depending on various conditions (state of rest or work, etc.). But under all conditions, alveolar air differs from inhaled air by a significantly lower oxygen content and a higher carbon dioxide content. This occurs as a result of the fact that in the pulmonary alveoli, oxygen enters the blood from the air, and carbon dioxide is released back.

Gas exchange in the lungs due to the fact that in pulmonary alveoli and venous blood flowing to the lungs, pressure of oxygen and carbon dioxide different: the oxygen pressure in the alveoli is higher than in the blood, and the carbon dioxide pressure, on the contrary, in the blood is higher than in the alveoli. Therefore, in the lungs the transition of oxygen from air to blood takes place, and carbon dioxide from blood to air. This transition of gases is explained by certain physical laws: if the pressure of a gas located in a liquid and in the air surrounding it is different, then the gas passes from the liquid to the air and vice versa until the pressure is balanced.

Table 3

In a mixture of gases, such as air, the pressure of each gas is determined by the percentage content of this gas and is called partial pressure(from the Latin word pars - part). For example, atmospheric air exerts a pressure equal to 760 mmHg. The oxygen content in the air is 20.94%. The partial pressure of atmospheric oxygen will be 20.94% of the total air pressure, i.e. 760 mm, and equal to 159 mm of mercury. It has been established that the partial pressure of oxygen in the alveolar air is 100 - 110 mm, and in the venous blood and capillaries of the lungs - 40 mm. The partial pressure of carbon dioxide is 40 mm in the alveoli, and 47 mm in the blood. The difference in partial pressure between blood and air gases explains gas exchange in the lungs. In this process, the cells of the walls of the pulmonary alveoli and blood capillaries of the lungs, through which gases pass, play an active role.

Lesson No. 7.

Topic: External respiration. The structure of the respiratory cycle.

Breath- a set of processes that result in the body consuming oxygen and releasing carbon dioxide.

Respiration in humans and higher animals includes the following processes:

1. Exchange of air between the external environment and the alveoli of the lungs.

2. Exchange of gases between alveolar air and blood flowing through the pulmonary capillaries.

3. Transport of gases by blood.

4. Exchange of gases between blood and tissues in tissue capillaries.

5. Cells consume oxygen and release carbon dioxide.

In unicellular organisms, gas exchange occurs through the entire surface of the body, in insects - through the trachea, which penetrates the entire body, in fish - in the gills. In amphibians, 2/3 of gas exchange occurs through the skin and 1/3 through the lungs. In mammals, gas exchange occurs almost entirely in the lungs and little through the skin and digestive tract.

External breathing.

The lungs of farm animals are located in a hermetically sealed chest cavity, where the pressure is negative (below atmospheric pressure). The inside of the chest cavity is lined with pleura, one of the layers of which (parietal) is adjacent to the chest, and the other (visceral) covers the lungs. Between them there is a gap filled with serous fluid to reduce friction of the lungs during inhalation and exhalation. The lungs are devoid of muscles and passively follow the movement of the chest: when the latter expands, they expand and suck in air (inhalation), when they collapse, they collapse (exhalation). The respiratory muscles of the chest and diaphragm contract due to impulses coming from the respiratory center, which ensures normal breathing. If you open the chest, air enters the pleural cavity (pneumothorax) and the pressure in it becomes equal to atmospheric pressure, as a result of which the lungs collapse (atelectasis).

Negative pressure in the pleural cavity.

In fetal animals, the lungs fill the entire chest cavity. Gas exchange occurs through the placenta. The fetal lungs do not participate in breathing.

After birth, with the first breath, the ribs rise, but cannot return to their original position, as they are fixed in the vertebrae.

The elastic tissue of the lungs tends to collapse; a gap is formed between the lungs and the chest, in which the pressure is below atmospheric. Thus, in the alveoli of the lungs the pressure is equal to atmospheric pressure – 760, in the pleural cavity – 745-754 mm Hg. These 10-30 mm ensure expansion of the lungs. When you inhale, the volume of the chest cavity increases, the pressure decreases, air enters the lungs. When the chest collapses, the chest cavity decreases, the pressure in it increases and air is forced out - exhalation occurs.

Under frequency breathing refers to the number of respiratory cycles (inhalation-exhalation) in 1 minute. The frequency of respiratory movements in animals depends on the intensity of metabolism, environmental temperature, animal productivity, etc.

Large animals breathe less frequently than small ones, young animals more often than adults. Highly productive cows breathe more often than low-producing cows. Physical work, eating food, and excitement increase breathing.

Respiratory rate

In animals in 1 min

Kind of animal	Frequency
Horse Cattle Pig Dog Chicken	8-12 10-30 8-18 10-30 22-25

The external and internal intercostal muscles and the muscles of the diaphragm take part in the act of breathing. Depending on which muscles are more involved in the expansion of the chest, three types of breathing are distinguished: costal or thoracic (when inhaling, the external intercostal muscles mainly contract); abdominal, or diaphragmatic (due to contraction of the diaphragm); costo-abdominal, when the muscles of the chest and diaphragm are involved in breathing. During pregnancy and diseases of the abdominal organs, the type of breathing changes to thoracic, since animals “protect” diseased organs.

When breathing, the chest expands and contracts. A recording of respiratory movements is called a pneumogram, from which the frequency and depth of breathing can be determined.

Protective respiratory reflexes include coughing, sneezing, stopping, increasing or rapid breathing.

Coughing and sneezing occur due to irritation of the receptors of the upper respiratory tract by mechanical particles and mucus. When coughing or sneezing, a sharp exhalation occurs with the glottis closed, as a result of which irritating substances are removed.

The body's defensive reaction is to stop breathing. If an animal is allowed to inhale ammonia, ether, chlorine or other pungent-smelling substances, breathing stops, which prevents irritating substances from entering the lungs.

Painful stimulation initially causes a delay and then an increase in breathing.

Transfer of gases by blood.

When you inhale, air enters the alveoli of the lungs, where gas exchange occurs through the capillaries. The inhaled air is a mixture of gases: oxygen - 20.82%, carbon dioxide - 0.03 and nitrogen - 79.15%. Gas exchange in the lungs occurs as a result of the diffusion of carbon dioxide from the blood into the alveolar air and oxygen from the alveolar air into the blood due to the difference in the partial pressure of gases in the alveolar air and blood.

Partial pressure- this is the part of the total pressure of the gas mixture attributable to the share of a particular gas in the mixture. Thus, the carbon dioxide tension in venous blood is 46 mm Hg. Art., and in the alveolar air - 40, oxygen in the alveoli of the lungs - 100 mm Hg. Art., and venous blood – 90.

The oxygen entering the blood dissolves in the plasma in an amount of 0.3 vol.%, and the rest binds to hemoglobin, resulting in the formation of oxyhemoglobin, which disintegrates in the tissues. The amount of oxygen that can bind 100 ml of blood is called blood oxygen capacity. The released hemoglobin binds with carbon dioxide (forming carbohemoglobin), 2.5 vol.% of carbon dioxide dissolves in the blood plasma. Carbon dioxide is released from the lungs with exhaled air.

Composition of inhaled and exhaled air

Target: mastering the skills to independently apply knowledge, skills and abilities in a complex manner, to transfer them to new conditions of practical and research activities

Tasks:

Educational: mastering the content of environmental education, the meaning of which is to understand the natural laws of nature and their correlation with the “artificial laws” of the development of society.

Developmental: development of key competencies of schoolchildren using the example of the content of environmental education; development of students' research skills to assess the state of various components of the environment.

Educational: formation of a system of basic values ​​(life, health, people, conservation of biological diversity, cultural heritage, etc.), creation of conditions for creative self-realization and self-development of schoolchildren.

Regulatory: organize your workplace under the guidance of a teacher; determine a plan for completing tasks in the lesson, evaluate the results of your activities.

Communicative: developed skills and habits of environmentally literate behavior in the environment, with other people, harmonious interaction and sustainable development in the “Nature - Society” system.

Planned results

Cognitive: students’ understanding of the values ​​of the phenomenon of life, the value of each form of existence of life; the value of human existence, his health, socio-cosmic significance; formation of key competencies based on environmental education;

Subject: the formation of a nature-conforming style of human behavior in the environment, based on knowledge of the laws of human interaction with the environment; development of ecological thinking, which presupposes the ability to establish cause-and-effect relationships, systematic analysis of reality, modeling and forecasting the development of the environment;

Personal: development of ecological thinking - flexible probabilistic thinking, which presupposes the ability to establish cause-and-effect relationships, systematic analysis of reality, modeling and forecasting of development and the environment; development of research skills in assessment and system analysis of the state of the environment.

Metasubject: connections with such academic disciplines as biology, chemistry, physics, geography - will contribute to a higher level of mastery of skills in this course and the implementation of tasks for pre-profile training of schoolchildren.

Lesson type -- demonstration in which the experiment serves as a visual aid

Form- forms of practice-oriented activities for students

Methods:, partially search, research, students conducting experiments.

Determination of the composition of inhaled and exhaled air

Goal of the work: study of the relative content of carbon dioxide in inhaled and exhaled air.

Information. The determination of carbon dioxide is carried out by the turbidity of lime water in order to compare the content of this air component before and after the student’s breathing. This is how the chemical reaction equation is written, which explains the cloudiness of lime water from exposure to air containing carbon dioxide.

The cloudiness is due to the formation of a suspension of insoluble calcium carbonate (CaC03 ). With further passage of air, a dissolution reaction of calcium carbonate occurs with the formation of the corresponding bicarbonate:

Thus, the turbidity disappears faster (or disappears altogether) in the flask through which the exhaled air passes.

Equipment included: 50 ml conical flasks with stoppers and L-shaped gas outlet tubes - 2 pcs., glass mouthpiece, pieces of rubber tube - 3 pcs., T-shaped glass tee.

Reagents and materials: lime water, swab, disinfectant solution (for preparation of solutions, see paragraph 3.3).

Progress

1.Assemble the device as shown in the figure.

2.Pour 74 volumes of lime water into each flask.

3.Wipe the mouthpiece thoroughly with a swab moistened with a disinfectant solution.

4. Exhale the air, then take the mouthpiece of the device into your mouth and slowly, so that the liquid does not get into your mouth, draw air through the mouthpiece. Through which flask does air enter the device?

5.Inhale and then exhale slowly into the mouthpiece. Through which flask does the exhaled air leave the device?

6.Take several inhalations and exhalations in a row through the mouthpiece. In which vessel did the limewater become cloudy?

Device for determining the composition of inhaled and exhaled air:

Processing of results and conclusions

1. Record the results of the experiments in your notebook.

2. Draw a conclusion from the experiment and write an equation for the chemical reaction that explains the turbidity of lime water

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