The pulmonary circulation begins in the right ventricle. Venous blood travels through the pulmonary arteries to the lungs. In the lungs, the arteries turn into capillary networks in which gas exchange occurs. Passing through the capillaries of the lungs, venous blood is cleared of carbon dioxide, saturated with oxygen and converted into arterial blood. The pulmonary veins drain arterial blood into the left atrium. It then passes from the left atrium to the left ventricle. where the systemic circulation begins again.
Pulmonary circulation: right ventricle -> lungs -> left atrium
It is called the pulmonary circulation because blood flows through it only to the lungs, where it is enriched with oxygen. In the second pulmonary circulation, the pulmonary arteries carry venous blood, and the pulmonary veins carry arterial blood. Cho exception: in the remaining veins (except for the umbilical) venous blood flows, and in the arteries - arterial blood.
The time for complete blood circulation in the systemic and pulmonary circulation is 20-25 s.
Through the systemic circulation, blood delivers oxygen and nutrients to all organs. In the pulmonary circulation, the blood is saturated with oxygen and cleared of carbon dioxide.
Blood movement. Blood pressure. The movement of blood through the vessels is caused by rhythmic contractions of the heart and unequal blood pressure in different parts of the circulatory system. Blood pressure is highest in arteries close to the heart. In the aorta it is 140-150 mm Hg. Art. Blood pressure decreases as you move away from the heart. In the large arteries of the arms and legs, the pressure is 105-120 mmHg. Art. In the capillaries the blood pressure is 20-40 mmHg. Art. In the veins the lowest pressure is from 0 to 9 10 mm Hg. Blood supply to organs depends on the functioning of the organ. The more actively an organ works, the more blood flows to it.
Blood pressure is usually measured at the brachial artery (Fig. 101). In healthy young people it is constant and at the same level. During heart contraction, the upper (systolic) pressure is observed. Its normal value is 100-120 mm Hg. Art. When the heart relaxes, lower (diastolic) pressure is noted. Its normal value is 60 -80 mm Hg. Art.
Blood pressure may also depend on atmospheric pressure. So. for example, in the mountains, as you rise, the atmospheric pressure decreases, and the arterial pressure increases accordingly. The pulse quickens. If a person, gradually descending underground, could reach its center, his blood pressure would drop catastrophically, and his heart would stop. You need to remember about the possibility of increased pressure while traveling in the mountains and climb only after special training.
Rice. 101. Measuring blood pressure with a tonometer
Pulse (from Latin pulse s - blow, push) - rhythmic vibrations of the walls of the arteries associated with contractions of the left ventricle of the heart. During its contraction, blood is expelled with force and great pressure into the aorta, which expands. The walls of the aorta begin to vibrate. Further vibrations quickly spread along the walls of the arteries. These fluctuations are called pulse. By pressing with your fingers on the inner surface of the wrists, on both sides of the neck, on the temples, you can feel the pulse (Fig. 102).
But the pulse can be determined by the number of heart contractions in 1 minute. In an adult, the pulse rate is 60-80 beats/min. During physical activity, the heart rate increases.
Rice. 102. Pulse is usually measured Fig. 103. An electrocardiogram is
electronic recording of heart function on the wrist
Text of the book “Biology. Human. 8th grade"
Test your knowledge
1. What is immunity?2. What cells and substances protect the body from pathogens and foreign substances?
3. Make a diagram of “Types of immunity”.
4. How is immunity acquired?
5. Artificial immunity is formed by introducing serum or vaccine. What is the difference between them?
6. How are the concepts of “vaccine” and “vaccination” related?
7. Who received the first vaccination?
8. What unites such phenomena as immunodeficiency, autoimmune diseases and allergic reactions?
9. What can cause immunodeficiency?
10. Decipher the abbreviation AIDS. Why is it wrong to say “get a blood test for AIDS”?
11. In what cases is a person at risk of contracting HIV infection? How to minimize the possibility of infection?
12. What is the essence of an autoimmune reaction? Give examples of autoimmune diseases.
13. Define the concept of “allergy”. What can it be expressed in?
14. What should a person do if they suspect an allergic reaction?
15. In what cases is blood transfusion given? What complications are possible during its implementation? What can cause them?
16. What blood types exist? On what basis are they distinguished?
17. Who is called a donor during a blood transfusion; recipient?
18. Why do you need to know your blood type?
19. Analyze the diagram. Make a conclusion which blood groups are compatible and which are not.
20. What is the Rh factor? Which people on Earth are more numerous: Rh-positive or Rh-negative?
21. Prove that the incompatibility of blood groups and the Rh factor is a special case of the body’s immune reaction.
Work with computer
Refer to the electronic application. Study the lesson material and complete the assigned tasks.
Internet link.
https://school-collection.edu.ru/catalog (Anatomical and physiological atlas of man / Internal environment of the body)
The outer membranes of our body prevent microbes from entering the body. Microbes that enter the body are destroyed by phagocytes. Immunity is the body's immunity to infectious diseases. There are natural and artificial immunity. Based on the presence or absence of certain antigens and antibodies in a person’s blood, four blood groups are distinguished. Depending on the presence of an antigen called “Rh factor” in red blood cells, people are divided into Rh positive and Rh negative.
Transport of substances
Circulatory organs
Blood is in constant movement. It flows through a gigantic network of blood vessels that penetrate all organs and tissues of the body. Vessels
and
the heart
are the circulatory organs.
The vessels through which blood flows from the heart are called arteries.
Arteries have thick, strong and elastic walls.
The largest artery is called the aorta.
The vessels that carry blood to the heart are called
veins.
Their walls are thinner and softer than the walls of arteries.
The smallest blood vessels are called capillaries.
They form a huge branched network that permeates our entire body. Capillaries connect arteries and veins with each other, close the circulatory circle and ensure continuous blood circulation.
The diameter of the capillary is several times thinner than a human hair. The walls of the capillaries are formed by only one layer of epithelial cells, so gases, soluble substances and white blood cells easily penetrate through them.
STRUCTURE OF THE HEART.
The central circulatory organ is the heart. This is a pump that drives blood through the vessels.
The heart lies in the chest cavity between the lungs, slightly to the left of the midline of the body. Its size is small, approximately the size of a human fist, and the average heart weight is from 250 g (in women) to 300 g (in men). The shape of the heart resembles a cone.
The heart is a hollow muscular organ divided into four cavities - chambers: the right and left atria,
right and left
ventricles.
The right and left halves do not communicate. The heart is located inside a special sac of connective tissue - the pericardium. Inside it contains a small amount of liquid that wets its walls and the surface of the heart: this reduces the friction of the heart during its contractions.
The ventricles of the heart have well-developed muscular walls. The walls of the atria are much thinner. This is understandable: the atria do much less work, driving blood into the adjacent ventricles. The ventricles push blood into the circulation with great force so that it can reach the areas of the body furthest from the heart through the capillaries. The muscular wall of the left ventricle is especially strongly developed.
Circulation diagram
The movement of blood occurs in a certain direction, this is achieved by the presence of valves in the heart. The movement of blood from the atria into the ventricles is regulated by the leaflet valves.
which can only open towards the ventricles.
The return of blood from the arteries to the ventricles is prevented by the semilunar valves.
They are located at the entrance to the arteries and have the appearance of deep semicircular pockets, which, under the pressure of blood, straighten, open, fill with blood, close tightly and thus block the return path of blood from the aorta and pulmonary trunk to the ventricles of the heart. When the ventricles contract, the semilunar valves are pressed against the walls, allowing blood to flow into the aorta and pulmonary trunk.
CIRCLES OF BLOOD CIRCULATION.
The human vascular system consists of two circles of blood circulation: large and small.
Systemic circulation
begins in the left ventricle, from where blood is pushed into the aorta. From the aorta, through branching arteries, it flows to all organs and tissues. In organs, small arteries break up into capillaries. Through the walls of the capillaries, the blood releases nutrients and oxygen into the tissue fluid, is saturated with carbon dioxide, collects waste products and becomes venous. This blood from the capillaries collects in small veins, which, merging, form larger ones. The superior and inferior vena cava bring venous blood to the right atrium.
From the right atrium, venous blood enters the right ventricle. The pulmonary circulation begins from it
Contracting, the right ventricle pushes blood into the pulmonary trunk, which divides into the right and left pulmonary arteries, which carry blood to the lungs. Here, in the pulmonary capillaries, gas exchange occurs: venous blood gives off carbon dioxide, is saturated with oxygen and becomes arterial. The four pulmonary veins return arterial blood to the left atrium.
• The heart begins to contract as early as the 19th or 20th day of fetal development. At first, the embryonic heart resembles a U-shaped tube, but between days 20 and 40 it becomes similar in overall configuration to the adult heart.
• The fact that the heart is a pump designed to pump blood through vessels would seem to be an obvious and well-known fact. However, before the publication of the book by the great Englishman William Harvey (1628), completely different ideas prevailed. Since ancient times, it was believed that the heart is the center of the “warmth” of the body, and in many vessels it is not even blood that circulates, but air. There is no doubt that Hippocrates, Aristotle and Galen were great scientists, but they made many mistakes when studying and describing the human circulatory system. W. Harvey proved that blood is not formed anew all the time, but its constant, relatively small amount circulates in the body. Moreover, blood moves through the vessels due to the pressure created by the contractions of the heart. Behind the followers of Aristotle and Galen stood the church, with which it was mortally dangerous to argue. And the arguments of Harvey’s opponents were not always correct. When W. Harvey, having opened the vessels of a dead dog, proved that they contained not air, but blood, they objected to him that blood collects in the vessels only after death, and in living creatures there is only air in the vessels. So argue with such opponents... Nevertheless, W. Harvey brilliantly proved that he was right; his doctrine of blood circulation was adequately appreciated during his lifetime. W. Harvey is rightly recognized as the founder of modern physiological science.
William Harvey
Test your knowledge
1. What structures make up the human circulatory system?
2. How are arteries different from veins? How does this relate to their functions?
3. What function do capillaries perform?
4. How does the heart work? Why is the muscular wall of the left ventricle much thicker than the muscular wall of the right ventricle?
5. What role do valves play in the circulatory system? Where else besides the heart do they meet?
6. Describe the movement of blood in the pulmonary circulation and the changes in its composition that occur.
7. Tell us about the path of blood through the systemic circulation, indicating the main vessels and what kind of blood (arterial or venous) moves through them.
8. Does arterial blood always move through arteries, and venous blood through veins? Support your answer with examples.
9. Why is it harmful to wear tight shoes and tight belts?
Work with computer
Refer to the electronic application. Study the lesson material and complete the assigned tasks.
Internet link.
https://school-collection.edu.ru/catalog (Anatomical and physiological atlas of humans / Circulatory and lymphatic systems)
The circulatory system consists of the heart and blood vessels - arteries, veins, capillaries. The human heart has four chambers (two atria, two ventricles). The systemic circulation begins in the left ventricle and ends in the right atrium. The pulmonary circulation begins in the right ventricle and ends in the left atrium.
Work of the heart
CARDIAC CYCLE.
Our heart is constantly at work. Scientists have calculated that per day it consumes enough energy to lift a load of 900 kg to a height of 14 m. But it works continuously for 70–80 years or more! What is the secret of his tirelessness?
This is largely due to the peculiarities of the heart. It consists of sequential contraction and relaxation with short intervals for rest. Three phases can be distinguished in one cardiac cycle. During the first phase, which lasts 0.1 s in an adult, the atria contract and the ventricles are in a relaxed state. It is followed by the second phase (it is longer - 0.3 s): the ventricles contract and the atria relax. After this, the third and final phase begins - a pause, during which a general relaxation of the heart occurs. Its duration is 0.4 s. The entire cardiac cycle takes 0.8 s.
You can see that during one cardiac cycle, the atria spend approximately 12.5% of the time of the cardiac cycle working, and the ventricles spend 37.5%. The rest of the time, which is 50%, the heart rests. This is the secret of the longevity of the heart and its amazing performance. Short periods of rest following each contraction allow the heart muscle to rest and recuperate.
Appearance of the heart
Another reason for the high performance of the heart is its abundant blood supply: at rest, 250–300 cm3 of blood per minute is supplied to it, and during heavy physical work - up to 2 thousand cm3.
REGULATION OF HEART FUNCTION.
The heart contracts (works) throughout a person’s life - during work, rest, sleep.
Usually we don’t think about it; it shrinks without our consciousness. We cannot control the functions of the heart. In the heart muscle there are special cells in which excitation occurs. It is transmitted to the atria and ventricles, causing their rhythmic contractions. These cells, their processes and the nodes they form form the conduction system of the heart. Spontaneous contractions of the heart are called cardiac automaticity.
Cardiac cycle
But the heart doesn't always work the same way. With excitement, physical work, and sports, the heart rate increases, and during sleep it decreases.
The autonomic nervous system regulates the functioning of the heart. Parasympathetic and sympathetic spinal nerves approach the heart. The parasympathetic nerves carry impulses that slow down and weaken the contractions of the heart, and the sympathetic nerves speed up and strengthen them. All changes in the functioning of the heart are reflexive in nature.
But not only the nervous system affects the functioning of the heart. It is also influenced by some adrenal hormones. For example, adrenaline increases your heart rate.
• Heart rate changes with age. A newborn's heart rate reaches 125 beats per minute. By the age of three, the heart rate drops to 100 beats, by the age of 5 to 90 beats, and finally by the age of 16 to 75 beats per minute. The trained hearts of athletes have an increased output of blood, and therefore, at rest, they beat less often than those of untrained people. For example, short-distance runners (sprinters) have a resting heart rate of 66 beats per minute, and marathon runners have a resting heart rate of 44 beats per minute.
• During a person’s life, the heart, without stopping for a moment, performs colossal work. The human heart beats at least 100 thousand times per day. If you live 70 years, then during these years your heart will contract 3 billion times! And this is without “repairs, replacement of parts, lubrication,” etc. Name any mechanism created by man that can work in the same way! But the heart does not work idle. It pumps blood: 7 thousand liters of blood pass through it in an hour, and in 70 years - 175 million liters! In order to work so intensely, the heart muscle must receive a lot of oxygen and nutrients from the blood.
Nodes of the conduction system of the heart
Test your knowledge
1. Analyze the text of the paragraph and draw up a diagram of the cardiac cycle illustrating the statement that the heart works as much as it rests.
2. What is the importance of its abundant blood supply for the performance of the heart?
3. Find out what is called the myocardium of the heart. What is the pathology of myocardial infarction?
4. What is the essence of heart automatism?
5. How does the sympathetic nervous system affect the functioning of the heart; parasympathetic nervous system? Is the heart subject to humoral regulation?
6. When does the heart rate increase and when does it decrease? What is this connected with?
Work with computer
Refer to the electronic application. Study the lesson material and complete the assigned tasks.
Internet link.
https://school-collection.edu.ru/catalog (Human anatomy and physiology / Circulatory and lymphatic systems)
In one cardiac cycle there are three phases: contraction of the atria, contraction of the ventricles and general relaxation of the heart.
The rhythm of work (alternating work and rest) and abundant blood supply ensure high performance of the heart.
Movement of blood through vessels
BLOOD PRESSURE.
The heart acts like a pump.
With each contraction of the ventricles, it forcefully releases another portion of blood into the vessels, creating pressure in them. The pressure under which the blood is held in the blood vessels is called blood pressure.
The highest pressure is in the aorta, and the lowest in the large veins. As you move away from the heart, the blood pressure in the vessels decreases. This is due to the fact that, as blood flows through the vessels, it overcomes the resistance created by friction against their walls. The narrower the vessels, the higher the pressure. The resulting pressure difference in different parts of the circulatory system is the main reason for its movement. Blood flows from an area of high pressure to an area of low pressure.
The heart pumps blood into the arteries in portions, but it moves through the vessels continuously. This is explained by the fact that the walls of large vessels are very elastic. With each blood supply, the aorta and other large arteries are stretched. When the heart relaxes, when blood pressure is reduced, the arteries, due to their elasticity, compress and return to their previous position, squeezing blood further towards smaller vessels.
Blood pressure in the circulatory system is not constant; it changes during different phases of the cardiac cycle. The pressure is greatest during ventricular contraction and is called maximum.
And
the minimum
pressure is during the period of relaxation of the heart.
The difference between them is called pulse
pressure, and it serves as an important indicator of normal heart function.
Blood pressure is measured using a special device - a tonometer. In a young healthy person, the maximum pressure should be about 120 mmHg. Art., and the minimum is 70 mm Hg. Art.
Measuring pressure with a tonometer
PULSE.
In some points of our body (for example, on the wrist), rhythmic shocks can be easily felt. This is a pulse - a periodic jerk-like expansion of the walls of the arteries, synchronous with the contractions of the heart. By the number of pulse beats one can judge the rhythm of the heart, the strength of its contractions, and the condition of the blood vessels.
At the moment of ejection of a portion of blood by the left ventricle, vibrations of the walls of the aorta occur; they quickly, at a speed of 7–10 m/s, spread through the arteries. We can feel them by pressing the arteries through the skin and muscles to the bone.
BLOOD FLOW SPEED.
This is an important indicator of blood circulation. The highest speed is in the aorta, and the lowest in the capillaries. This is due to the fact that the total lumen of all capillaries in our body is 1000 times larger than the lumen of the aorta, so according to the laws of physics, blood flows in them a thousand times slower. This has enormous biological meaning: thanks to the slow movement of blood through the capillaries in the tissues, gas exchange occurs, metabolic products are collected in the blood, and nutrients are distributed to organs and tissues.
In capillaries, blood flows at a speed of 0.5 mm/s, in the aorta - 500 mm/s, in large veins - 200 mm/s, and the total blood circulation time is 20–25 s.
BLOOD MOVEMENT THROUGH THE VEINS.
This movement has its own peculiarities. The walls of veins, unlike arteries, are soft and thin; blood pressure in small veins barely reaches 10 mm Hg. Art., and in large veins it is even lower. Rising from the lower extremities up to the heart, the blood must overcome its own gravity. Therefore, contraction of skeletal muscles and pressure of internal organs play an important role in the movement of blood through the veins. By contracting, the muscles compress the veins and squeeze blood out of them. Blood moves in one direction - towards the heart thanks to special valves similar to cardiac semilunar valves. All veins of the lower and upper extremities and many others have such valves.
HEART TRAINING.
A person must take care of his heart from childhood and train it.
During running or heavy physical work, the body's need for oxygen increases approximately 8 times. This means that the heart must pump 8 times more blood than usual. In a person leading a sedentary lifestyle, this is achieved by increasing heart rate. However, an untrained heart with weak cardiac muscle cannot work with increased load for a long time. It quickly gets tired, and the blood supply increases very briefly, and then completely deteriorates.
The heart of a trained person is a powerful muscle. Such a heart can work for a long time without getting tired.
An active lifestyle and physical work significantly contribute to strengthening the heart muscle.
LYMPHATIC SYSTEM AND LYMPH MOVEMENT.
Tissue fluid washes cells and tissues, giving them nutrients and oxygen and at the same time being saturated with metabolic products.
Then part of the tissue fluid is absorbed into blindly starting lymphatic capillaries,
which form a widely branched network.
Merging with each other, the capillaries form lymphatic vessels,
which eventually flow into large veins in the lower parts of the neck. The lymphatic system filters tissue fluid, removing foreign substances from it.
Along the routes of lymph there are lymph nodes,
performing the function of biological filters: passing through them, lymph is cleared of dead, decayed cells, microorganisms and enters the veins already filtered.
The lymphatic system is part of the immune system and is involved in protecting the body from foreign substances.
Lymph tissue of a lymph node
• One of the common vascular diseases is varicose veins. In this hereditary or lifelong disease, a defect in the valves of large veins develops, usually in the lower extremities. As a result, the lumen of the veins increases unevenly, nodes and convolutions appear, and the walls of the veins become thinner. All this leads to stagnation of blood, bleeding, and ulcers on the skin. Varicose veins of the legs are often observed in those people who are forced to stand for a long time during the day: salespeople, hairdressers. After all, the muscles of their legs are in the same state for a long time, and for good venous blood flow it is necessary that the muscles surrounding the veins contract all the time, pushing the blood up the veins. Then there will be no stagnation of blood in the veins.
Test your knowledge
1. What causes blood to move through the vessels?
2. What is blood pressure called?
3. Why is the movement of blood through the vessels continuous, despite the fact that the heart ejects blood rhythmically, in separate portions?
4. What pressure is called maximum; minimal? What are their normal values for a healthy young person?
5. What is pulse pressure?
6. What is pulse? How is it measured? What is its normal value at rest?
7. In which parts of the bloodstream does blood move at the highest speed; lowest speed? (Please provide specific values.)
8. What is the biological meaning of the slow movement of blood through the capillaries?
9. Thanks to what features of the anatomy and physiology of the circulatory system does blood move through the veins in one direction, including against gravity?
10. How can you train your heart muscle?
11. How are the circulatory and lymphatic systems interconnected?
12. What is the importance of the lymphatic system for the body?
13. Why does lymph pass through the lymph nodes before entering the blood?
14. Is the human circulatory system closed or open; lymphatic system?
Laboratory and practical work
Complete work No. 10 “Measurement of blood pressure”, (Notebook for laboratory and practical work) and on p. 86 “Determination of pulse and counting the number of heartbeats” (Workbook).
Work with computer
Refer to the electronic application. Study the lesson material and complete the assigned tasks.
Internet link.
https://school-collection.edu.ru/catalog (Anatomical and physiological atlas of humans / Circulatory and lymphatic systems)
Contractions of the heart and the difference in pressure in the vessels ensure the movement of blood through the vessels. Continuity of blood flow is achieved by the elasticity of the artery walls. The pulse is the rhythmic vibration of the walls of the arteries.
Thematic control test on the topic “Circulatory system”
Test on the topic “Circulatory system”
Part A.
For each task in Part A, several answers are given, of which only one is correct. Choose the correct answer in your opinion.
1
.
Hemoglobin is:
1) leukocyte protein 2) plasma protein 3) erythrocyte protein
2
.
The blood vessels through which blood moves from the heart are:
1) veins of the pulmonary circulation 2) veins of the systemic circulation; 3) arteries of the pulmonary and systemic circulation 4) capillaries of the systemic and pulmonary circulation
3
.
What kind of blood flows in the veins of the systemic circulation:
1) venous; 2) arterial; 3) oxygenated; 4) mixed.
4. Veins are:
1) vessels carrying venous blood; 2) vessels carrying arterial blood; 3) vessels carrying blood to the heart; 4) vessels carrying blood from the heart.
5. The pulmonary circulation includes veins:
1) liver; 2) lungs; 3) upper limbs; 4) lower extremities.
The pulmonary circulation ends
1) right atrium 2) right ventricle 3) left atrium 4) left ventricle
7.
The heart valve that prevents the movement of blood from the right ventricle to the right atrium is called:
1) bicuspid 2) pouch-shaped 3) semilunar 4) tricuspid
8.
The human heart has a chamber structure. Number of cameras
:
1) 3 2) 2 3) 4 4) 5
9. How long does ventricular relaxation last during one cardiac cycle?
1) 0.3 s 2) 0.8 s 3) 0.5 s 4) 0.4 s
10.
Substance that enhances the work of the heart:
1) adrenaline 2) acetylcholine 3) potassium salts 4) water
11.
The highest blood pressure is in
1) in the superior vena cava 2) in the aorta 3) in the artery 4) in the vessels of the brain
12. The reason for the continuous movement of blood through the vessels:
1) high blood pressure in capillaries compared to arteries;
2) equal pressure in arteries and veins;
3) an increase in pressure as blood moves through the vessels from arteries to veins;
4) high pressure in the arteries and low in the veins;
13.The most dangerous thing is... bleeding
1) arterial 2) venous 3) internal 4) capillary
14.
The reason for the fatigue of the heart muscle is
1) alternating its contraction and relaxation
2) the possibility of reflex changes in the work of the heart
3) multinucleation of muscle tissue cells
15. Transport of carbon dioxide from tissues to lungs is carried out
1) leukocytes 2) lymphocytes 3) phagocytes 4) erythrocytes
16. In case of external bleeding, first of all it is necessary
1) apply a pressure bandage or tourniquet 2) apply a dry sterile bandage 3) treat the wound with iodine 4) treat the area of the body around the wound with hydrogen peroxide
17.
The most developed muscular wall has:
1) the left atrium; 2) left ventricle; 3) right ventricle; 4) right atrium.
18.
The main difference between cardiac muscle tissue and skeletal muscle tissue:
1) can generate nerve impulses; 2) capable of involuntary contraction;
3) its cells contain actin and myosin; 4) its activity is controlled by the brain.
19.
The main function of platelets is:
1) transport of oxygen from the lungs to all organs 2) protection of the body 3) transport of nutrients 4) participation in blood clotting
20. Vessels of the systemic circulation DO NOT carry blood to
1) brain 2) skin 3) lungs 4) kidneys
Part B.
1
.
In the task it is necessary to establish in what sequence in the human body blood moves through the systemic circulation:
A) veins of the systemic circulation; B) arteries of the head, arms and torso; B) aorta;
D) capillaries of a large circle; D) left ventricle; E) right atrium.
Answer: …
2. Establish a correspondence between the ventricle of the heart and the characteristics of the blood flowing from it.
| BLOOD | Ventricle |
| A) Arterial | 1) left |
| B) Venous | 2) right |
| B) Saturated with oxygen | |
| D) Unsaturated with oxygen | |
| D) Enters the pulmonary circulation |
| A | B | IN | G | D |
3. Establish a correspondence between the structural features and the type of blood vessels for which they are characteristic.
| SIGNS | TYPE OF VESSEL |
| A) single-layer wall | 1) arteries |
| B) there are valves inside | 2) capillaries |
| C) gas exchange occurs in them | 3) veins |
| D) the middle layer consists of muscle tissue and is well developed | |
| D) the lowest pressure | |
| E) in the small circle they contain venous blood |
| A | B | IN | G | D | E |
4.Insert into the text “Structure and functioning of the circulatory system” the missing terms from the proposed list, using their serial numbers.
| Blood in the human body moves in a continuous flow through ... (A) circulatory circles - ... (B) and ... (C). Moving along ... (D) the blood circulation, the blood is saturated with ... (D) and is freed from carbon dioxide. In the systemic circulation, blood carries oxygen and ... (E) to all organs and takes away carbon dioxide and excretory products from them. The direct movement of blood occurs through the vessels: ... (G), ... (H), veins. The vessels carrying blood from the heart to the organs are called ... (I), and from the organs to the heart - ... (K). |
List of terms
| big | two | veins | capillaries | nutrients |
| pulmonary | small | oxygen | arteries |
Answers
Part A
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| 1) | X | X | X | X | |||||||||||||||
| 2) | X | X | X | X | |||||||||||||||
| 3) | X | X | X | X | X | X | X | ||||||||||||
| 4) | X | X | X | X | X |
Part B
1.
Answer: DVBGAE
2
.
| A | B | IN | G | D |
| 1 | 2 | 1 | 2 | 2 |
3.
| A | B | IN | G | D | E |
| 2 | 3 | 2 | 1 | 3 | 1 |
4.
A – two; B – large; B - small; G – pulmonary; D – oxygen; E – nutrients; F – arteries; Z-capillaries; I- arteries; K - veins.
Grading norms
:
"5" - 0-1 errors
“4” – 3-5 errors
“3” - 6-8 errors
"2" > 8 errors
