Small circle circulation

Circulation circles - This concept is conditional, since only fish the circulation circle is completely closed. All other animals, the end of a large circle of blood circulation is the beginning of a small and vice versa, which does not make it possible to talk about their complete closet. In fact, both circle of blood circulation constitute a single integer blood drone, in two sections of which (right and left heart), blood is reported to kinetic energy.

Circulation circle - This is a vascular path that has its origin and end in the heart.

Big (system) circle of blood circulation

Structure

It begins with the left ventricle ejecting blood in the aorta during systole. Numerous arteries depart from the aorta, as a result, the bloodstream is distributed across several parallel regional vascular networks, each of which bloodsink separate organ. Further division of the arteries occurs on arterioles and capillaries. The total area of \u200b\u200ball capillaries in the human body is about 1000 m².

After the passage of the organ, the process of mergering capillaries in Vienuly, which, in turn, are collected in Vienna. Two hollow veins are suitable for the heart: the upper and lower, which for the fusion form part of the right atrium of the heart, which is the end of a large circle of blood circulation. Blood Courage B. big Circle Blood circulation occurs in 24 seconds.

Exceptions in structure

• Circulating the spleen and intestines. The general structure does not include blood circulation in the intestine and spleen, since after the formation of the spleen and intestinal veins, they merge forming a portal vein. The gorgeous vein is repeatedly disintegrating into the liver to the capillary network, and only after that the blood comes to heart.
• Blooming kidney. In the kidney, there are also two capillary networks - the arteries are disintegrated to bring the arterioles of the Capsules of Schulyansky-Bowman, each of which decomposes onto the capillaries and is collected in the arteriole. The endowing arteriol comes to an apart from the nefron and repeatedly disintegrates on the capillary network.

Functions

The blood supply to all organs of the human body, including the lungs.

Small (pulmonary) circle circulation

Structure

Starts in the right ventricle, throwing blood into the pulmonary trunk. The pulmonary trunk is divided into the right and left pulmonary artery. The arteries are dyhotomically divided into equity, segmental and subsecmentation arteries. Subsecment arterys are divided into arterioles disintegrating on the capillaries. Outflow blood is coming On veins going in reverse order, which in the amount of 4 pieces fall into the left atrium. A blood circulation in a small circulation circle occurs in 4 seconds.

The small circle of blood circulation was first described by Migesel Servero in the XVI century in the book "Restoration of Christianity".

Functions

• Heat Pot.

Small Circle function is not Power supply of lung fabric.

"Additional" circle circles

Depending on the physiological state of the body, as well as practical expediency, additional circles of blood circulation sometimes distinguish:

• placental
• cordial.

Placentational circle of blood circulation

There is a fetus located in the uterus.

Blood not completely saturated with oxygen, moves through the umbilical vein passing in the umbilical cord. From here, most of the blood comes through the venous duct into the lower hollow vein, mixing with the neoxygenated blood from the bottom of the body. The smaller part of the blood enters the left branch of the portal vein, passes through the liver and hepatic veins and enters the lower hollow vein.

At the bottom of the hollow vein flows mixed blood, the saturation of which oxygen is about 60%. Almost all this blood enters through an oval hole in the wall of the right atrium into the left atrium. From the left ventricle, blood is thrown into a large circle of blood circulation.

Blood from the upper hollow vein first enters the right ventricle and pulmonary trunk. Since the lungs are in the saving condition, the pressure in pulmonary arteries is greater than in the aorta, and almost all the blood passes through arterial (BOTALLOV) duct into the aorta. Arterial dashing Flips in the aort after removing the arteries of the head and the upper limbs from it, which ensures them more enriched with blood. In the lungs, a very small part of the blood flows, which in the future goes into the left atrium.

Part of the blood (~ 60%) from a large circle of blood circulation, through two pupil artery enters the placenta; The rest is to the organs of the bottom of the body.

Cardiac circle of blood circulation or coronary blood circulation system

It is structurally part of a large circle of blood circulation, but due to the importance of the body and its blood supply, it is sometimes possible to meet the mention of this circle in the literature.

Arterial blood comes to the heart on the right and left coronary artery. They start at the aorta above its semi-lunged valves. More minor branches are departed from them, which enter the muscular wall branch up to the capillaries. Outflow venous blood It occurs in 3 veins: large, medium, small, vein hearts. Merging, they form a bemark sinus and it opens into the right atrium.

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Subtitles

Big (system) circle of blood circulation

Structure

Functions

The main task of a small circle is gas exchange in lightweight alveols and heat transfer.

"Additional" circle circles

Depending on the physiological state of the body, as well as practical expediency, additional circles of blood circulation sometimes distinguish:

• placental
• cordial

Placentational circle of blood circulation

The blood of the mother enters the placenta, where he gives oxygen and nutrients capillaries of the umbilical vein of the fetus passing along with two arteries in the umbilical cepochetus. Underfloor vein gives two branches: most of the blood flows through the venous duct directly into the lower hollow vein, mixing with the neoxygenated blood from the bottom of the body. The smaller part of the blood enters the left branch of the portal vein, passes through the liver and liver veins and then also enters the lower hollow vein.

After birth, the umbilical vein starts and turns into a round ligament of the liver (Ligamentum Teres Hepatis). Venous duct also turns into scar tape. In premature babies, venous duct can function for some time (usually scares after a while. If not - there is a risk of developing liver encephalopathy). With portal hypertension, the umbilical vein and alanecium ducts can be recanalized and served by way of workarounding blood flow (Porto-Cavalny Shunts).

At the bottom of the hollow Vienna, mixed (arterial-venous) blood, the saturation of which is oxygen about 60%; Viennic blood flows on the upper hollow vein. Almost all the blood from the right atrium through an oval hole enters the left atrium and, further, the left ventricle. From the left ventricle, blood is thrown into a large circle of blood circulation.

The smaller part of the blood comes from the right atrium into the right ventricle and the lung barrel. Since the lungs are in the saving condition, the pressure in the light arteries is greater than in the aorta, and almost all the blood passes through arterial (Botalles) duct into the aorta. The arterial duct falls into the aorta after the appearance of the arteries of the head and the upper limbs from it, which provides them with more enriched blood. In the lungs, a very small part of the blood flows, which in the future goes into the left atrium.

Part of the blood (about 60%) from a large circle of blood circulation on two umbilical arteries of the fetus enters the placenta; The rest is to the organs of the bottom of the body.

With a normally functioning placenta, the blood of the mother and the fetus is never mixed - this explains the possible difference in blood groups and the Mother's Russel factor (s). However, the definition of a blood group and the reserves of a newborn child for cord blood is often erroneous. In the process of generic placenta, the overload: swelling and the passage of the placenta by the generic channel contribute to the melting maternal Blood in the umbilical cord (especially if the childhood was "unusual" or the pathology of pregnancy was noted). For the unmistakable determination of the blood group and the reserves factor of the newborn, the blood should be taken not from the umbilical cord, but by the child.

Heart Blood Supply or Blood Circle

It is part of a large circle of blood circulation, but due to the importance of the heart and its blood supply, it is sometimes possible to meet the mention of this circle in the literature.

Arterial blood comes to the heart on the right and left coronary arteries, originating at the aorta above its semi-lunk valves. Left coronary artery is divided into two or three, less often four artery, of which the most clinically significant are anterior downward (PMW) and envelope branches (s). The front descending branch is the immediate continuation of the left coronary artery and descends to the top of the heart. The envelope branch departs from the left coronary artery at its beginning approximately at right angles, envelopes the heart in front of the back, sometimes reaching the rear wall of the interventricular furrow. The arteries come into the muscular wall, branching to the capillaries. The outflow of venous blood takes place mainly in 3 veins of the heart: large, middle and small. Magicia, they form a bemark sinus, opening in the right atrium. The rest of the blood reaches the front cordial veins and tebeziyev veins.

Ring Willia or Willisia Circle

Willisyev circle - an arterial ring formed by the arteries of the vertebrate pool and inner carotid arteries, located at the base of the brain, contributes to compensation for blood supply deficiency. In the norm of the Willisye circle closed. In the formation of the Willisye circle, the front connecting Artery, the initial segment of the anterior brain artery (A-1), the supraklinoid part of the inner carotid artery, the rear connecting artery, the initial segment of the rear brain artery (P-1).

Cardiovascular system is an important component of any living organism. Blood transports oxygen to tissues, various nutrients and hormones, and the products of the exchange of these substances transfers to the allocation authorities for their excretion and neutralization. It is enriched with oxygen in the lungs, nutrients in the organs of the digestive system. In the liver and kidney, metabolic products are output and neutralized. These processes are carried out by constant blood circulation, which occurs with the help of greater and small circles of blood circulation.

General

Attempts to open the circulatory system were in different centuries, but truly understood the essence of the circulatory system, opened its circles and described the scheme of their structure English doctor William Garvey. He first proved that in the body of an animal the same amount of blood is constantly moving along a closed circle due to pressure, which is created by heart abbreviations. In 1628, Gaver released a book. In it, he outlined his teaching about circles of blood circulation, creating the prerequisites for further in-depth study of the anatomy of the cardiovascular system.

In newborn children, blood circulates on both circles, but while the fruit was in the womb, his blood circulation had its own characteristics and was called placental. This is due to the fact that during the development of the fetus in the womb and digestive system The fetus is not fully functional, and it receives all the necessary substances from the mother.

Building circles structure

The main component of blood circulation is the heart. Big and small circles of blood circulation are formed by the vessels from him and are closed circles. They consist of vessels of various structures and diameter.

According to the function of blood vessels, they are accepted for the following groups:

1. 1. Summer. They start and finish both circle of blood circulation. These include pulmonary trunk, aorta, hollow and pulmonary veins.
2. 2. Mains. They distribute blood throughout the body. These are large and medium sized supplied artery and veins.
3. 3. Organ. With their help ensures the metabolism between the blood and tissues of the body. This group includes intraganic veins and arteries, as well as a microcirculatory link (arterioles, venules, capillaries).

Small circle

It works to saturate blood oxygen, which occurs in the lungs. Therefore, this circle is also called pulmonary. He begins in the right ventricle, which passes all the venous blood entered into the right atrium.

The beginning is the pulmonary trunk, which, when approaching easy, branches on the right and left pulmonary artery. They carry the lungs of venous blood to Alveola, which gave carbon dioxide And having received oxygen in return, it becomes arterial. Blood-saturated oxygen on the pulmonary veins (two on each side) enters the left atrium, where the small circle ends. Then blood flows into the left ventricle, where does the big circle of blood circulation originate.

Big circle

He originates in the left ventricle the largest vessel of the human body - aorta. It carries arterial blood containing substances and oxygen necessary for vital activity. The aorta branches his arteries going to all tissues and organs, which subsequently cross the arterioles and then in capillaries. Through the wall of the latter, the metabolism and gases between the fabrics and vessels occurs.

Having obtained the products of exchange and carbon dioxide, blood becomes venous and going to Vienuly and further in Vienna. All veins merge into two large vessels - lower and upper hollow veins, which are then falling into the right atrium.

Functioning and value

Blood circulation is carried out due to heart cuts, combined operation of its valves and pressure gradient in organ vessels. With this, the necessary sequence of blood flow in the body is set.

Due to the action of circles of blood circulation, the body continues to exist. The constant circulation of blood is important for life and performs the following functions:

• gas (delivery of oxygen to organs and tissues and a removal from them according to the venous part of carbon dioxide);
• transportation of nutrients and plastic substances (come to fabrics in arterial channel);
• delivery of metabolites (recycled substances) to the allocation bodies;
• transport of hormones from the place of their development to the target authorities;
• circulation of thermal energy;
• delivery of protective substances to the place of claim (to places of inflammation and other pathological processes).

The coordinated work of all the links of the cardiovascular system, as a result of which there is continuous blood flow between the heart and organs, allows the exchange of substances with the external environment and maintain the constancy of the inner medium for the full functioning of the body for a long time.

Mammals and man has the most difficult circulatory system. This is a closed system consisting of two circles of blood circulation. Providing warm-bloodedness, it is more energetically beneficial and allows a person to occupy that niche habitat in which he is now.

The blood circulation system is a group of hollow muscle organs responsible for the blood circulation along the organism vessels. It is represented by the heart and vessels of different caliber. These are muscle organs that form circles of blood circulation. Their scheme is offered in all textbooks on anatomy and is described in this publication.

Concept of circles of blood circulation

The blood circulation system consists of two circles - bodily (large) and pulmonary (small). The circulation around the blood circulation is the system of vessels of arterial, capillary, lymphatic and venous type, which carries out blood from the heart into the vessels and its movement in the opposite direction. The central is the heart, since there are two circle of blood circulation without mixing arterial and venous blood.

Big circle circulation

A large circulation circle is a system for providing peripheral fabrics by arterial blood and its return to the heart. It begins from where the blood comes out into the aorta through the aortal opening from the aorta blood is heading towards smaller body arteries and comes to capillaries. This is a combination of organs forming a leading link.

Here in the fabric comes oxygen, and carbon dioxide is captured by erythrocytes. Also in tissue, blood transport amino acids, lipoproteins, glucose, whose metabolism products are made from the capillaries to Vienuly and further into larger veins. They fall into hollow veins that return blood directly to the heart into the right atrium.

The right atrium ends a large circle of blood circulation. The scheme looks like this (in the course of blood circulation): left ventricle, aorta, elastic arteries, muscular-elastic arteries, muscle artery, arterioles, capillaries, venules, veins and hollow veins, returning blood to heart into the right atrium. From the large circle of blood circulation they feed on the brain, all skin, bones. In general, all human fabrics feed on the vessels of a large circle of blood circulation, and small is just the place of blood oxygenation.

Small circle circulation

The pulmonary (small) circle of blood circulation, the scheme of which is presented below, originates from the right ventricle. It gets blood from the right atrium through an atrioventricular hole. From the cavity of the right ventricle depleted oxygen (venous) blood through the output (pulmonary) tract enters the pulmonary trunk. This artery is thinner aorta. It is divided into two branches, which are sent to both light.

Lightweight is a central body that forms a small circle of blood circulation. The human scheme described in the textbooks on anatomy explains that pulmonary blood flow is needed for blood oxygenation. Here it gives carbon dioxide and absorbs oxygen. In the sinusoidal capillaries of the lungs with an atypical body with a diameter of about 30 microns and there is gas exchange.

Subsequently, the blood saturated with oxygen is directed through the system of intramilia veins and is assembled in 4 pulmonary veins. All of them are attached to the left atrium and carry blood rich oxygen. There are circles circulation on this and end. The scheme of a small pulmonary circle looks like this (in the course of blood flow): right ventricle, pulmonary artery, intra-light arteries, pulmonary arterioles, pulmonary sinusoids, Venules, left atrium.

Features of the circulatory system

The key feature of the circulatory system, which consists of two circles is the need for a heart with two or more cameras. In fish circle of blood circulation, one, because they have no lungs, and the entire gas exchange takes place in the vessels of the gills. As a result, fishing the heart is a single-chamber - this is a pump, pushing blood only in one direction.

Amphibians and reptiles have respiratory organs and, accordingly, circulation circles. The scheme of their work is simple: blood from the ventricle is directed to the vessels of a large circle, from the arteries - in capillaries and veins. The venous refund to the heart is also implemented, however, from the right atrium, blood gets into a common circle of blood circulation of the ventricle. Since the heart of these animals is three-chamber, then blood from both circles (venous and arterial) is mixed.

In humans (and mammals), the heart has a 4-chamber structure. In it, two ventricles and two atrium are separated by partitions. The lack of mixing of two types of blood (arterial and venous) has become a giant evolutionary invention, which ensured the warm-bloodedness of mammals.

And heart

In the system of blood circulation, which consists of two circles, the power of light and heart is of particular importance. These are the most important organs that ensure the closure of the bloodstream and the integrity of respiratory and blood systems. So, the lungs have two circle of blood circulation in their thicker. But their fabric feeds at the expense of the vessels of a large circle: bronchial and pulmonary vessels, carrying blood to the parenchyma of the lung, are born from the aorta and from the domestic arteries. And from the right departments, the body cannot eat, although part of the oxygen diffuses and from there. It means a large and small circles of blood circulation, the scheme of which is described above, perform different functions (one enriches blood oxygen, and the second sends it to the organs, taking the deoxygenic blood from them).

The heart is also powered by the vessels of a large circle, but the blood in its cavities is able to provide an oxygen endocardium. In this case, part of the veins of myocardium, mainly small, flows directly in noteworthy that the pulse wave on coronary artery It applies to cardiac diastole. Therefore, the organ is rudder only when "resting".

Human circulation circles, the scheme of which is presented above in the appropriate sections, provide warm-bloodedness, and high endurance. Let a person are not the animal that often uses its strength to survive, but the rest of the mammal has made it possible to populate certain habitat. Previously, they were not available to amphibians and reptiles, and even more so fish.

In phylogenesis, a large circle appeared earlier and was characteristic of fish. And the small circle supplemented it only in those animals that were completely or completely went to the land and settled it. From the moment of its appearance, the respiratory system and blood circulation are considered together. They are connected functionally and structurally.

This is an important and already indecided evolutionary mechanism of exiting an aquatic habitat and setting up sushi. Therefore, the continuing complication of mammalian organisms will now head not towards the complication of the respiratory and blood system, but in the direction of amplification of oxygen-binding and increasing the lung area.

A large circle of blood circulation begins in the left ventricle. Here is the mouth of the aorta, where blood will be released while reducing the left ventricle. Aorta is the largest unpaired vessel from which numerous arteries are diverted in different directions, according to which the blood flow is distributed, supplying the cells of the organism necessary for their development substances.

If the blood of a person stops moving, he will die, because it is it that provides cells and organs necessary for growth and development elements, supplies them oxygen, takes away waste and carbon dioxide. The substance is moving along the network of blood vessels, which permeate all the tissues of the body.

Scientists believe that there are three circle of blood circulation: hearty, small, large. The concept is conditional, because the total circle of blood flow is the vascular path, which begins, ends in the heart and is characterized by a closed system. There is only such a structure in fish, whereas in other animals, as well as a large circle goes into small, and vice versa, the liquid fabric from the small leaks into a large.

For moving the plasma (liquid blood) corresponds to the heart, which is a hollow muscle, which consists of four parts. They are located as follows (according to blood movement on the heart muscle):

• right atrium;
• right ventricle;
• left atrium;
• left ventricle.

At the same time, the muscle body is arranged so that with the right side, the blood is directly in the left can not get. At first she needs to be milded, where it falls along the pulmonary arteries, where the purification of a saturated carbon dioxide is occurring. Another feature in the structure of the heart is the fact that the blood flow is performed only forward and is impossible in the opposite direction: this is hampered by special valves.

How plasma moves

A feature of the ventricles is that it is in them that the small and large circles of blood flow begin. It takes its beginning a small circle in the right ventricle, where the plasma falls from the right atrium. From right ventricle Liquid fabric goes to easy pulmonary arteryWhat diverges into two branches. In the lungs, the substance gets to pulmonary bubbles, where red blood cells break up with carbon dioxide and attach to themselves oxygen molecules, which is why the blood brightened. Then the plasma on the pulmonary veins is in the left atrium, where its current over a small circle is completed.

From the left atrium, the liquid substance goes into the left ventricle, where does the large circle of blood flow originate. After the ventricle is compressed, blood releases in the aorta.

The ventricles are characterized by more developed walls than atrium, since their task is to push the plasma with such a force so that it can get to all cells of the body. Therefore, the muscles of the wall of the left ventricle, from which a large circulation circle begins, are developed more than the vascular walls of other heart chambers. This gives him the opportunity to provide plasma current on a rabid speed: it takes place in a large circle in less than thirty seconds.

The area of \u200b\u200bblood vessels along which the liquid tissue is dispersed in the body, in an adult exceeds 1 thousand m 2. Blood through the capillaries transmits the tissues the components you need, oxygen, then takes carbon dioxide and waste, purchasing a darker color.

The plasma is then moving to Venory, after which it flows to the heart to bring the decay products to the outside. When blood approaches the heart muscle, Venules are collected in larger veins. It is believed that in the veins contained about seventy per cent: their walls are more elastic, thin and soft than the arteries, therefore it is stronger stretching.

Approaching the heart, the veins converge into two large vessels (hollow veins), which are included in the right atrium. It is believed that in this part of the heart muscle a large circle of blood flow ends.

Due to what is moving blood

For the flow of blood according to the vessels, the pressure is responsible that the heart muscle creates rhythmic cuts: the liquid tissue moves from the site with more high pressure in the side of the lower. The greater the difference between the pressures, the sooner the plasma flows.

If we talk about a big circle of blood flow, then the pressure at the beginning of the path (in the aorta) is much higher than at the end. The same applies to the right circle: the pressure in the right ventricle is much larger than in the left atrium.

Reducing blood velocity occurs primarily due to its friction on vascular walls, which leads to a slowdown in blood flow. In addition, when blood flows through a wide channel, the speed is much larger than when it diverges through artiol and capillaries. This gives the capillars to convey the necessary substances to the tissues and pick up waste.

In hollow veins, pressure becomes equal to atmospheric and maybe even lower. So that liquid tissue on the veins can move in low pressure conditions, breathing is activated: during the inhalation, the pressure in the sternum decreases, which leads to an increase in the difference at the beginning and end of the venous system. Also help venous blood move skeletal muscles: when they are reduced, squeeze veins, which contributes to blood circulation.

Thus, blood moves by blood vessels Due to the complex system, in which a huge number of cells, tissues, organs are involved, and the cardiovascular system is played a huge role. If at least in one structure, which is involved in the bloodstream, will fail (blockage or narrowing of the vessel, impairment of the heart, injury, hemorrhage, tumor), blood flow will break, which causes serious health problems. If this happens that blood will stop, the man will die.