Blood constantly circulates throughout the body, providing transport various substances. It consists of plasma and suspension of various cells (the main ones are erythrocytes, leukocytes and platelets) and moves along a strict route - the system of blood vessels.
Venous blood - what is it?
Venous - blood that returns to the heart and lungs from organs and tissues. It circulates through the pulmonary circulation. The veins through which it flows lie close to the surface of the skin, so the venous pattern is clearly visible.
This is partly due to a number of factors:
- It is thicker, saturated with platelets, and if damaged, venous bleeding is easier to stop.
- The pressure in the veins is lower, so when the vessel is damaged, the volume of blood loss is lower.
- Its temperature is higher, so in addition it prevents the rapid loss of heat through the skin.
The same blood flows in both arteries and veins. But its composition is changing. From the heart, it enters the lungs, where it is enriched with oxygen, which transfers to internal organs providing them with food. The veins that carry arterial blood are called arteries. They are more elastic, the blood moves through them in jerks.
Arterial and venous blood do not mix in the heart. The first passes on the left side of the heart, the second - on the right. They are mixed only with serious pathologies of the heart, which entails a significant deterioration in well-being.
What is the systemic and pulmonary circulation?
From the left ventricle, the contents are pushed out and enter the pulmonary artery, where they are saturated with oxygen. Then, through the arteries and capillaries, it spreads throughout the body, carrying oxygen and nutrients.
The aorta is the largest artery, which then divides into superior and inferior. Each of them supplies blood to the upper and lower parts of the body, respectively. Since the arterial “flows around” absolutely all organs, is supplied to them with the help of an extensive system of capillaries, this circle of blood circulation is called large. But the volume of the arterial at the same time is about 1/3 of the total.
Blood flows through the pulmonary circulation, which gave up all the oxygen, and "took" metabolic products from the organs. It flows through the veins. The pressure in them is lower, the blood flows evenly. Through the veins, it returns to the heart, from where it is then pumped to the lungs.
How are veins different from arteries?
Arteries are more elastic. This is due to the fact that they need to maintain a certain rate of blood flow in order to deliver oxygen to the organs as quickly as possible. The walls of the veins are thinner, more elastic. This is due to a lower blood flow rate, as well as a large volume (venous is about 2/3 of the total volume).
What kind of blood is in the pulmonary vein?
The pulmonary arteries provide oxygenated blood to the aorta and its further circulation through the systemic circulation. The pulmonary vein returns some of the oxygenated blood to the heart to feed the heart muscle. It is called a vein because it brings blood to the heart.
What is saturated in venous blood?
Coming to the organs, the blood gives them oxygen, in return it is saturated with metabolic products and carbon dioxide, and acquires a dark red hue.
A large amount of carbon dioxide is the answer to the question why venous blood is darker than arterial blood and why veins are blue. It also contains nutrients that are absorbed in the digestive tract, hormones and other substances synthesized by the body.
Venous blood flow depends on its saturation and density. The closer to the heart, the thicker it is.
Why are tests taken from a vein?
This is due to the fact that the blood in the veins is saturated with metabolic products and the vital activity of organs. If a person is sick, it contains certain groups of substances, the remains of bacteria and other pathogenic cells. In a healthy person, these impurities are not found. By the nature of impurities, as well as by the level of concentration of carbon dioxide and other gases, it is possible to determine the nature of the pathogenic process.
The second reason is that venous bleeding during a vessel puncture is much easier to stop. But there are times when bleeding from a vein does not stop for a long time. This is a sign of hemophilia, a low platelet count. In this case, even a small injury can be very dangerous for a person.
How to distinguish venous bleeding from arterial:
- Assess the volume and nature of the flowing blood. The venous one flows out in a uniform stream, the arterial one is thrown out in portions and even "fountains".
- Assess what color the blood is. Bright scarlet indicates arterial bleeding, dark burgundy indicates venous bleeding.
- Arterial is more liquid, venous is thicker.
Why does the venous fold faster?
It is thicker, contains a large number of platelets. A low blood flow rate allows the formation of a fibrin network at the site of damage to the vessel, for which platelets “cling”.
How to stop venous bleeding?
With a slight damage to the veins of the limbs, it is enough to create an artificial outflow of blood by raising an arm or leg above the level of the heart. A tight bandage should be applied to the wound itself to minimize blood loss.
If the injury is deep, a tourniquet should be applied to the area above the injured vein to limit the amount of blood flowing to the injury site. In summer it can be kept for about 2 hours, in winter - for an hour, a maximum of one and a half. During this time, you need to have time to deliver the victim to the hospital. If you keep the tourniquet longer than the specified time, tissue nutrition will be disturbed, which threatens with necrosis.
It is advisable to apply ice to the area around the wound. This will help slow down the circulation.
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Blood performs an important function in the body - it provides all organs and tissues with oxygen and various useful substances. From the cells, it takes carbon dioxide, decay products. There are several types of blood: venous, capillary and arterial blood. Each type has its own function.
General information
For some reason, almost all people are sure that arterial blood is the kind that flows in arterial vessels. In fact, this opinion is wrong. Arterial blood is enriched with oxygen, because of this it is also called oxygenated. It moves from the left ventricle to the aorta, then goes through the arteries of the systemic circulation. After the cells are saturated with oxygen, the blood turns into venous blood and enters the veins of the BC. In a small circle, arterial blood moves through the veins.
Different types of arteries are located in different places: some are deep in the body, while others allow you to feel the pulsation.
Venous blood moves through the veins in the BC and through the arteries in the MC. It has no oxygen. This liquid contains a large amount of carbon dioxide, decomposition products.
Differences
Venous and arterial blood are different. They differ not only in function, but also in color, composition and other indicators. These two types of blood have a difference in bleeding. First aid is provided differently.
Function
Blood has specific and general functions. The latter include:
- nutrient transfer;
- transportation of hormones;
- thermoregulation.
Venous blood contains a lot of carbon dioxide and little oxygen. This difference is due to the fact that oxygen enters only the arterial blood, and carbon dioxide passes through all the vessels and is contained in all types of blood, but in different quantities.
Colour
Venous and arterial blood has a different color. In the arteries, it is very bright, scarlet, light. In the veins, the blood is dark, cherry-colored, almost black. It has to do with the amount of hemoglobin.
When oxygen enters the blood, it enters into an unstable combination with the iron contained in red blood cells. Once oxidized, iron turns blood bright red. Venous blood contains a lot of free iron ions, due to which it becomes dark in color.
Blood movement
Asking the question of what is the difference between arterial and venous blood, few people know that these two types also differ in the movement through the vessels. In the arteries, blood moves away from the heart, and through the veins, on the contrary, towards the heart. In this part of the circulatory system, circulation is slow as the heart pushes fluid away from itself. Also, the valves located in the vessels affect the decrease in the speed of movement. This type of blood movement occurs in the systemic circulation. In a small circle, arterial blood moves through the veins. Venous - through the arteries.
In textbooks, on a schematic representation of blood circulation, arterial blood is always colored red, and venous blood is blue. Moreover, if you look at the diagrams, then the number of arterial vessels corresponds to the number of venous ones. Such an image is exemplary, but it fully reflects the essence of the vascular system.
The difference between arterial blood and venous blood also lies in the speed of movement. Arterial is ejected from the left ventricle into the aorta, which branches into smaller vessels. Then the blood enters the capillaries, nourishing all organs and systems at the cellular level with useful substances. Venous blood is collected from the capillaries into larger vessels, moving from the periphery to the heart. When a fluid moves, different pressures are observed in different areas. Arterial blood pressure is higher than venous blood pressure. It is ejected from the heart under a pressure of 120 mm. rt. Art. In the capillaries, the pressure drops to 10 millimeters. It also moves slowly through the veins, as it has to overcome gravity, to cope with the system of vascular valves.
Due to the difference in pressure, blood for analysis is taken from capillaries or veins. Blood is not taken from the arteries, since even a slight damage to the vessel can provoke extensive bleeding.
Bleeding
When providing first aid, it is important to know which blood is arterial and which is venous. These species are easily identified by the nature of the flow and color.
With arterial bleeding, a fountain of bright scarlet blood is observed. The liquid flows out pulsatingly, quickly. This type of bleeding is difficult to stop, this is the danger of such injuries.
When rendering first aid, it is necessary to raise the limb, to transfer the damaged vessel by applying a hemostatic tourniquet or by pressing it down with finger pressure. With arterial bleeding, the patient must be taken to the hospital as soon as possible.
Arterial bleeding may be internal. In such cases, a large amount of blood enters the abdominal cavity or various bodies. With this type of pathology, a person sharply becomes ill, skin turn pale. After a while, dizziness, loss of consciousness begins. This is due to the lack of oxygen. Only doctors can help with this type of pathology.
With venous bleeding, dark cherry-colored blood flows from the wound. It flows slowly, without pulsation. You can stop this bleeding yourself by applying a pressure bandage.
Circles of blood circulation
There are three circles of blood circulation in the human body: large, small and coronary. All blood flows through them, so if even a small vessel is damaged, severe blood loss can occur.
The pulmonary circulation is characterized by the release of arterial blood from the heart, passing through the veins to the lungs, where it is saturated with oxygen and returned back to the heart. From there, it goes through the aorta to a large circle, delivering oxygen to all tissues. Passing through various organs, the blood is saturated with nutrients, hormones, which are carried throughout the body. In the capillaries, there is an exchange of useful substances and those that have already been worked out. This is where oxygen exchange takes place. Fluid flows from the capillaries into the veins. At this stage, it contains a lot of carbon dioxide, decay products. Through the veins, venous blood is carried throughout the body to organs and systems, where purification from harmful substances, then the blood approaches the heart, passes into a small circle, where it is saturated with oxygen, giving off carbon dioxide. And everything starts over.
Venous and arterial blood must not mix. If this happens, it will reduce the physical capabilities of a person. Therefore, with pathologies of the heart, operations are performed that help to normal image life.
For human body both types of blood are important. In the process of blood circulation, the fluid passes from one type to another, ensuring the normal functioning of the body, as well as optimizing the work of the body. The heart pumps blood at a tremendous speed, without stopping its work for a minute, even during sleep.
The blood that constantly circulates in the body is not the same everywhere. In some parts of the vascular system, it is venous, in others it is arterial. What is this substance in each case, and how does venous blood differ from arterial? This is discussed below.
General information
Among the functions of the blood, the most important is the supply of food and oxygen to the tissues, as well as the release of the body from metabolic products. All this movement of vital fluid occurs along a closed trajectory. In this case, there is a division of the system into two sectors, called circles of blood circulation. Small - passes through the lungs, where oxygen enters the blood. Large - permeates the entire body, its organs and tissues.
The heart beats make the blood move. The largest vessels come directly from this organ. Gradually, they narrow, branch and pass into the capillaries. The arteries, veins and smaller vessels are shown below and the movement of blood is shown:
Comparison
Each type of blood has its own composition. Arterial is the one that is oxygenated. In addition, it contains a sufficient amount of useful elements, as it nourishes the cells of the body. In a large circle, such blood flows, respectively, through the arteries, in the direction from the heart. But in the small, despite the name, - through the veins.
Everything happens the other way around in the case of venous blood. In a large circle, it moves to the main organ through the veins, and in a small circle, it goes from the heart to the lungs through the arteries. Such blood carries a lot of carbon dioxide and metabolic products, but there are practically no all kinds of nutrients in it. Arterial blood turns into a liquid with the specified composition after the return of useful components to the tissues of the body. Thus, an important substance, circulating along a closed path, regularly, when passing through certain sections, changes its type.
Let us name other signs that make up the difference between venous and arterial blood. Visually, the differentiating factor is color. At venous blood it is deep, dark red with a cherry tint. The arterial fluid, in turn, is brighter. It is revealed that its temperature is somewhat lower.
Another feature by which comparison can be made is the speed of movement of the composition of both types. So, venous blood has a more measured course. This is due to the action of some physical forces, and the fact that the veins are equipped with valves that control such movement. By the way, these vessels are clearly visible under the skin in certain areas of the body, for example, in the wrist area.
Because of low pressure venous blood, which is also thicker, comes out calmly when the body is injured. It's easier to stop her. Meanwhile, it is very difficult to cope with arterial bleeding, which has an intense pulsating character. This phenomenon is very dangerous for human life.
What is the difference between venous and arterial blood? The fact that when determining diseases, the material of the first type is more often taken. After all, it is venous blood, saturated with waste products, that can tell more about any problems in the body.
Blood in medicine is usually divided into arterial and venous. It would be logical to think that the first flows in the arteries, and the second in the veins, but this is not entirely true. The fact is that in the systemic circulation, arterial blood (a.k.) indeed flows through the arteries, and venous blood (v.k.) flows through the veins, but in the small circle the opposite happens: c. to. comes from the heart to the lungs through the pulmonary arteries, gives off carbon dioxide to the outside, is enriched with oxygen, becomes arterial and returns from the lungs through the pulmonary veins.
How is venous blood different from arterial blood? A. to. saturated with O 2 and nutrients, it comes from the heart to organs and tissues. V. to. - “worked out”, it gives O 2 and nutrition to the cells, takes away CO 2 and metabolic products from them and returns from the periphery back to the heart.
Human venous blood differs from arterial blood in color, composition and functions.
by color
A. to. has a bright red or scarlet hue. This color is given to it by hemoglobin, which has attached O 2 and become oxyhemoglobin. V. to. contains CO 2, therefore its color is dark red, with a bluish tinge.
Composition
In addition to gases, oxygen and carbon dioxide, other elements are contained in the blood. In a. to. a lot of nutrients, and in c. to. - mainly metabolic products, which are then processed by the liver and kidneys and excreted from the body. The pH level also differs: a. c. it is higher (7.4) than c. k. (7.35).
On the move
The circulation of blood in the arteries and venous systems is significantly different. A. to. moves from the heart to the periphery, and c. to. - in the opposite direction. When the heart contracts, blood is ejected from it at a pressure of approximately 120 mm Hg. pillar. When it passes through the capillary system, its pressure is significantly reduced and is approximately 10 mm Hg. pillar. Thus, a. to. moves under pressure at high speed, and c. It flows slowly under low pressure, overcoming gravity, and valves prevent its reverse flow.
How the transformation of venous blood into arterial and vice versa occurs can be understood if we consider the movement in the small and large circles of blood circulation.
The CO 2-rich blood travels through the pulmonary artery to the lungs, where the CO 2 is expelled to the outside. Then O 2 is saturated, and the blood already enriched with it through the pulmonary veins enters the heart. This is how movement occurs in the pulmonary circulation. After that, the blood makes a big circle: a. to. through the arteries carries oxygen and nutrition to the cells of the body. Giving O 2 and nutrients, it is saturated with carbon dioxide and metabolic products, becomes venous and returns to the heart through the veins. This completes the systemic circulation.
By function
Main function a. k. - the transfer of nutrition and oxygen to the cells through the arteries of the systemic circulation and the veins of the small. Passing through all organs, it gives off O 2, gradually takes away carbon dioxide and turns into venous.
Through the veins, the outflow of blood is carried out, which took away the waste products of cells and CO 2. In addition, it contains nutrients that are absorbed digestive organs, and hormones produced by the endocrine glands.
By bleeding
Due to the peculiarities of the movement, bleeding will also differ. With arterial blood in full swing, such bleeding is dangerous and requires prompt first aid and medical attention. With a venous one, it calmly flows out in a jet and can stop on its own.
Other differences
- A. to. is located in the left side of the heart, c. to. - in the right, mixing of blood does not occur.
- Venous blood is warmer than arterial blood.
- V. to. flows closer to the surface of the skin.
- A. to. in some places comes close to the surface and here you can measure the pulse.
- The veins through which flows in. to., much more than the arteries, and their walls are thinner.
- A.K. movement is provided by a sharp ejection during heart contraction, outflow into. the valve system helps.
- The use of veins and arteries in medicine is also different - they are injected into a vein medications, it is from it that a biological fluid is taken for analysis.
Instead of a conclusion
Main differences a. to. and in. to. lie in the fact that the first is bright red, the second is burgundy, the first is saturated with oxygen, the second is carbon dioxide, the first moves from the heart to the organs, the second - from the organs to the heart.
Blood in the vessels of the human body moves continuously. The heart, due to its structure, clearly divides it into arterial and venous. They should not normally mix. Sometimes difficult situations arise, for example, when bleeding or fluid is taken from a vessel, in which it is necessary to accurately determine its type. This article will tell you how it differs from venous. Let's start with anatomy.
The structure of the circulatory system
The four-chamber structure of the heart contributes to the differentiation of arterial and venous fluid. Thus, they do not mix, which is necessary for the adequate functioning of the body.
There are 2 circles of blood circulation: small and large. Thanks to the first, blood passes through the capillaries of the lungs, is enriched with oxygen in the alveoli, becoming arterial. Then she goes to the heart, which, with the help of the powerful walls of the left ventricle, pushes her into a large circle through the aorta.
After the tissues of the body have taken all the nutrients from the capillaries, the blood becomes venous and returns to the heart through the vessels of the same name of the large circle, which directs it through the pulmonary arteries to the small one in order to saturate it with oxygen again.
So what is the difference between arterial blood and venous blood? What are their features?
Arterial
First of all, this species differs from the other in composition. The main function of blood is to deliver oxygen to organs and tissues. The process takes place in capillaries - the smallest vessels. In exchange for oxygen, cells give off carbon dioxide.
In addition to the most important chemical element for all living things, such blood is rich in nutrients that are absorbed into gastrointestinal tract and enter the vein. Further, her path is blocked by the liver. All substances from the gastrointestinal tract must be filtered. Dangerous and poisonous ones remain there, and pure venous blood gets the right to pass through the lungs and be transformed into arterial. It also delivers nutrients to the organ cells in need of nutrition.
Another distinctive feature of this type of blood is the color. It has a bright scarlet color. The reason is hemoglobin. It has a different composition. So what is the difference between hemoglobin in arterial and venous blood? This is a special protein that can carry oxygen. Connecting with it gives the liquid a bright scarlet color.
Another important feature that distinguishes arterial blood from venous blood is the nature of movement through the vessels. This directly depends on the force with which it is expelled from the heart into a large circle, as well as on the structure of the wall of the arteries. They are strong and elastic. Therefore, in case of injury, the contents of the vessel are poured out in a strong pulsating jet.
Compressing the arteries using soft tissue is very difficult. Therefore, to stop blood loss, there are points where the vessels adjoin as close as possible to the bone structures. It is necessary to press the artery firmly against the bone structure above the injury site, since the arteries carry blood from top to bottom. It must be remembered that most of the arteries are deep, it takes a lot of effort to clamp them.
Venous
This species has a darker, deeper burgundy color with a slight bluish tinge. This color is due to hemoglobin. Arterial to the maximum gave oxygen to the tissues of the body. But therefore, venous blood differs from arterial blood in the presence of another substance in hemoglobin - carbon dioxide. This is how carboxyhemoglobin is formed. It just colors the substance in a dark red hue.
After the transfer of nutrients, the tissues give up their metabolic products, which must be removed from the body. Such substances include uric acid other. Because of them high content compared to arterial blood, it is venous blood that is used in laboratory research for the qualitative determination of one or another indicator.
Venous blood differs from arterial blood in that it will flow more systematically if the vessel is damaged. It is much easier to stop this type of bleeding, especially with superficial trauma. It is enough to apply a pressure bandage. This difference in movement through the vessels is explained by the structure of the vein wall. She is very pliable, it is easy to press her to soft tissues such as muscles.
Meaning
Due to their differences, opposite characteristics, arterial and venous blood ensure the internal constancy of the body - homeostasis. For full health, you need to keep yourself in good shape and maintain complete balance. Otherwise, if any deviations appear, the condition will be disturbed and the person will fall ill.
How is arterial blood different from venous blood? After reading the article, such a question should not bother a person. Based on the knowledge gained, you can easily determine the type of bleeding and save more than one life.