Human venous blood as opposed to arterial blood. What is the difference between arterial and venous blood?

Why is the blood almost black from the vein, but not thick?

As you know, blood can be venous and arterial.

Arterial oxygenation in the lungs.

Venous blood is saturated carbon dioxide as a result of metabolic processes in the body.

Venous blood is dark red, almost black blood (in low light).

The color and thickness of blood are concepts from several different planes. The color is determined by the oxygen saturation of the blood and the number of red blood cells. Thickness is reflected in the folding of the protein. platelets seem to be involved.

Blood from a vein is black in color because there is almost no oxygen and a large amount of carbon dioxide in the veins. Because of all this, she became so dark. After it passes through your lungs it will become brighter.

The dark color of venous blood is absolutely normal, this is how it should be, perhaps even with a bluish tint. The color depends on the characteristics of a particular organism. The more oxygen the blood gives to the organs, the darker it will be.

Venous blood always has a very dark, almost black tint. Arterial, on the contrary, is bright scarlet. Arterial blood is saturated with oxygen, and venous blood, passing through the vessels, loses a significant part of it and is saturated with carbon dioxide. For this reason, its color also changes.

Human blood has venous and arterial blood. Accordingly, the arterial one is bright red, as it is saturated with oxygen. Venous blood is dark in color, since its function is saturation with carbon dioxide.

This normal condition. Venous blood is poor in oxygen and rich in carbon dioxide. But the color of blood and its density are in no way related concepts. Don't worry about this - everything is fine with you.

The thickness of the blood has nothing to do with its color. Whether the blood will be thicker or thinner depends on the degree of coagulation, and this in turn depends on the amount of protein. The color indicates the oxygen saturation of the blood. It is because of this arterial blood in the light it is much lighter than the venous one.

When I was playing sports, we often took blood for tests at the physical dispensary (the medical commission was regular and mandatory), then I discovered this oddity, I asked the doctor, he said everything was fine, deoxygenated blood without oxygen(well, almost) this is where the color comes from.

Blood contains a protein called hemoglobin. It contains iron, and it is found in red blood cells - these are blood cells.

These red blood cells give blood its famous red color. And that's why the color of blood can be different, it all depends on the presence in this moment It depends on the oxygen content in the blood cells.

The human body contains both arterial and venous blood. And venous blood differs in color, it is darker, it has little oxygen. But blood from an artery is bright red, because it is well saturated with oxygen.

Venous blood contains carbon dioxide, which gives dark color to her.

The color of blood is actually determined by its saturation; either oxygen or carbon dioxide.

The dark color in the veins is their normal state, since they are already on the way back when they have already delivered oxygen to the capillaries and, in return, collected carbon dioxide for delivery to the exchanger, that is, to the lungs.

Finally, about the thickness of the blood, which depends on its viscosity and the causes of which are; shaped elements blood cells They increase density. And the second is plasma density-reducing. Imbalance between shaped elements plasma and is the cause of the blood condition.

That's it, fuck you, you're becoming a vampire! Joke. What should it be like? Venous blood is always very dark, almost black in some people. This occurs due to the fact that there is almost no oxygen in the venous blood and a lot of carbon dioxide. This is why it becomes dark. It will pass through the lungs and become bright scarlet and arterial.

Constant movement of blood through a closed circuit cardiovascular system, which ensures gas exchange in tissues and lungs, is called blood circulation. In addition to saturating organs with oxygen, as well as cleansing them of carbon dioxide, blood circulation is responsible for delivering all necessary substances to the cells.

Everyone knows that blood can be venous and arterial. In this article you will learn through which vessels more dark blood, find out what is included in this biological fluid.

This system includes blood vessels, which penetrate all tissues of the body and the heart. The process of blood circulation begins in the tissues where metabolic processes through the capillary walls.

The blood, which has given up all its useful substances, flows first to right half heart, and then into the pulmonary circulation. There she became rich useful substances, moves to the left, and then spreads in a large circle.

The heart is the main organ in this system. It is endowed with four chambers - two atria and two ventricles. The atria are divided interatrial septum, and the ventricles - interventricular. The weight of a human “motor” is from 250-330 grams.

The color of the blood in the veins and the color of the blood moving through the arteries are slightly different. You will learn a little later about which vessels the darker blood moves through and why it differs in shade.

An artery is a vessel that carries biological fluid saturated with useful substances from the “motor” to the organs. The answer to a fairly frequently asked question: “What vessels carry venous blood?” simple Venous blood is transported exclusively by the pulmonary artery.

The arterial wall consists of several layers, these include:

outer connective tissue membrane;
medium (consisting of smooth muscles and elastic hairs);
internal (consisting of connective tissue and endothelium).

Arteries divide into small vessels called arterioles. As for capillaries, they are the smallest vessels.

The vessel that carries carbon dioxide-enriched blood from tissues to the heart is called a vein. The exception in this case is the pulmonary vein, since it carries arterial blood.

Dr. W. Harvey first wrote about blood circulation back in 1628. The circulation of biological fluid occurs through the pulmonary and systemic circulation.

The movement of biological fluid in the systemic circle begins from the left ventricle, thanks to high blood pressure, the blood spreads throughout the body, nourishes all organs with beneficial substances and takes away harmful ones. Next, the transformation of arterial blood into venous blood is noted. Final stage- return of blood to the right atrium.

As for the small circle, it begins from the right ventricle. First, the blood gives off carbon dioxide, receives oxygen, and then moves to the left atrium. Next, through the right ventricle, the flow of biological fluid into the systemic circle is noted.

The question of which vessels carry darker blood is quite common. Blood is red in color; it differs only in shades due to the amount of hemoglobin and oxygen enrichment.

Surely many remember from biology lessons that arterial blood has a scarlet tint, and venous blood has a dark red or burgundy tint. Veins located nearby skin, also appear red when blood circulates through them.

In addition, venous blood differs not only in color, but also in function. Now, knowing through which vessels darker blood moves, you know that its color is due to its enrichment in carbon dioxide. The blood in the veins has a burgundy tint.

It contains little oxygen, but at the same time it is rich in metabolic products. It is more viscous. This is due to an increase in the diameter of red blood cells due to the influx of carbon dioxide into them. In addition, the temperature of the venous blood is higher, and the pH is lower.

It circulates through the veins very slowly (due to the presence of valves in the veins that slow down the speed of its movement). Ven in human body compared to arteries, much larger.

What color is the blood in the veins and what functions does it perform?

Do you know what color the blood in the veins is? The shade of biological fluid determines the presence of hemoglobin in red blood cells (erythrocytes). The blood circulating through the arteries, as already mentioned, is scarlet.

This is due to the high concentration of hemoglobin (in humans) and hemocyanin (in arthropods and mollusks), enriched with various nutrients.

Venous blood has a dark red tint. This is due to oxidized and reduced hemoglobin.

At the very least, it is unreasonable to believe the theory according to which the biological fluid circulating through the vessels is bluish in color, and when injured and in contact with air due to a chemical reaction, it immediately turns red. It is a myth.

Veins may only appear bluish, this is due to simple laws physicists. When light hits the body, the skin reflects some of all the waves and therefore looks light or dark (this depends on the concentration of the coloring pigment).

You know what color venous blood is, now let's talk about the composition. You can distinguish arterial blood from venous blood using laboratory research. Oxygen tension - 38-40 mmHg. (in venous), and in arterial blood - 90. The content of carbon dioxide in venous blood is 60 millimeters of mercury, and in arterial blood - about 30. The pH level in venous blood is 7.35, and in arterial blood - 7.4.

The outflow of blood, carrying away carbon dioxide and products formed during metabolism, is carried out through the veins. It is enriched with useful substances that are absorbed into the walls of the gastrointestinal tract and produced by vital substances.

Now you know what color the blood is in the veins, you are familiar with its composition and functions.

Blood flowing through the veins overcomes “difficulties” during movement, which include pressure and gravity. That is why, in case of damage, biological fluid flows in a slow stream. But if the arteries are injured, blood spurts out like a fountain.

The speed at which venous blood moves is much less than the speed at which arterial blood moves. The heart pumps blood out under high pressure. After it passes through the capillaries and becomes venous, a decrease in pressure to ten millimeters of mercury is noted.

Why is venous blood darker than arterial blood, and how to determine the type of bleeding

You already know why venous blood is darker than arterial blood. Arterial blood is lighter and this is due to the presence of oxyhemoglobin in it. As for the venous, it is dark (due to the content of both oxidized and reduced hemoglobin).

You've probably noticed that blood is taken from a vein for testing, and you've probably wondered, “why from a vein?” This is due to the following. The composition of venous blood includes substances that are formed during metabolism. In pathologies, it is enriched with substances that ideally should not be in the body. Thanks to their presence, it is possible to identify the pathological process.

Now you know not only why the blood in the veins is darker than the arterial blood, but also why blood is taken from the vein.

Anyone can determine the type of bleeding; there is nothing difficult about it. The main thing is to know the characteristics of biological fluid. Venous blood has a darker shade (why venous blood is darker than arterial blood is indicated above), and it is also much thicker. When cut, it flows out in a slow stream or drops. But as for the arterial one, it is liquid and bright. When wounded, it sprays like a fountain.

It is easier to stop venous bleeding; sometimes it stops on its own. Typically, a tight bandage is used to stop bleeding (placed below the wound).

As for arterial bleeding, everything is much more complicated. It is dangerous because it does not stop on its own. In addition, blood loss can be so large that death can occur literally within an hour.

Capillary bleeding can open even with minimal injury. The blood flows out calmly, in a small stream. Such damage is treated with brilliant green. Next, a bandage is applied to them, which helps stop bleeding and prevent pathogenic microorganisms into the wound.

As for the venous, when damaged, blood flows out somewhat faster. In order to stop bleeding, a tight bandage is applied, as already mentioned, below the wound, that is, further from the heart. Next, the wound is treated with 3% peroxide or vodka and bandaged.

As for the arterial one, it is the most dangerous. If you have already been injured and you see bleeding from the artery, you must immediately raise the limb as high as possible. Next, you need to bend it and pinch the wounded artery with your finger.

Then a rubber tourniquet (rope or bandage will do) is applied above the wound site, after which it is tightened tightly. The tourniquet must be removed no later than two hours after application. While the bandage is being applied, a note is attached indicating the time of application of the tourniquet.

Bleeding is dangerous and fraught great loss blood and even fatal. That is why in case of injury it is necessary to call ambulance or take the patient to the hospital yourself.

Now you know why the blood in the veins is darker than the blood in the arteries. Blood circulation is a closed system, which is why the blood in it is either arterial or venous.

Venous blood flows from the heart through the veins. It is responsible for moving carbon dioxide throughout the body, which is necessary for blood circulation. The main difference between venous blood and arterial blood is that it has more high temperature and contains less vitamins and microelements.

Arterial blood flows in capillaries. This smallest points on the human body. Each capillary carries a certain amount of liquid. The entire human body is divided into veins and capillaries. It's flowing there certain type blood. Capillary blood gives a person life and ensures the flow of oxygen throughout the body and most importantly to the heart.

Arterial blood is red and flows throughout the body. The heart pumps it to all remote corners of the body, so that it circulates everywhere. Its mission is to saturate the entire body with vitamins. This process keeps us alive.

Venous blood is blue-red in color, contains metabolic products, and flows through veins with very thin walls. She withstands the impact high pressure, because when the heart contracts, changes can form that the vessels must withstand. Veins are located above the arteries. They are easy to see on the body and easier to damage. But venous blood is thicker than arterial blood and flows out more slowly.

The most severe wounds for humans are the heart and groin. These places must always be protected. All the blood in a person flows through them, so with the slightest damage a person can lose all the blood.

There is a large and small circle of blood circulation. In the small circle, the liquid is saturated with carbon dioxide and flows to the lungs from the heart. It leaves the lungs, saturated with oxygen, and enters a large circle. Blood, based on carbon dioxide, runs from the lungs to the heart; through the capillaries, the lungs carry blood based on vitamins and oxygen.

Oxygenated blood is located on the left side of the heart, and venous blood is located on the right. During the contraction of the heart, arterial blood enters the aorta. This is the main vessel of the body. From there, oxygen flows down and ensures the functioning of the legs. The aorta is the most important artery for humans. It, like the heart, cannot be damaged. This can lead to rapid death.

The role and functions of venous blood

Venous blood is often used for human research. It is believed that it speaks better about human diseases, because it is a consequence of the work of the body as a whole. In addition, it is not difficult to take blood from a vein, because it flows worse than a capillary, so a person will not lose much blood during the operation. The largest human arteries should not be damaged at all, and if it is necessary to do a study of arterial blood, it is taken from a finger in order to minimize the negative consequences for the body.

Venous blood is used by doctors for prevention diabetes mellitus. It is necessary that the level of sugar in the veins does not exceed 6.1. Arterial blood is clear liquid, which flows through the body, nourishing all organs. Venous absorbs the waste products of the body, cleansing it. Therefore, it is by this type of blood that human diseases can be determined.

Bleeding can be external and internal. Internal is more dangerous for the body and occurs when human tissue is damaged with inside. Most often, this occurs after a very deep external wound or a malfunction in the body leading to tissue rupture from the inside. Blood begins to flow into the crack, and the body feels oxygen starvation. The person begins to turn pale and loses consciousness. This occurs because too little oxygen reaches the brain. Venous blood can be lost due to internal bleeding and this will be harmless to humans, but arterial blood is not. Internal bleeding quickly blocks brain function due to lack of oxygen. This will not happen with external bleeding, because the connection between human organs is not disrupted. Although, loss large quantity blood is always fraught with loss of consciousness and death.

Summary

So, the main difference between venous blood and arterial blood is this color. Venous is blue, and arterial is red. Venous is rich in carbon dioxide, and arterial is rich in oxygen. Venous flows from the heart to the lungs, where it turns into arterial, saturated with oxygen. The arterial flows through the aorta from the heart throughout the body. Venous blood contains metabolic products and glucose, arterial blood is saltier.

Arterial blood is located on the left side of the heart, venous blood on the right. Blood should not mix. If this happens, it will increase the workload on the heart and reduce physical abilities person. In lower animals, the heart consists of one chamber, which inhibits their development.

Both types of blood are very important for humans. One feeds it, and the other collects it harmful substances. In the process of blood circulation, blood passes one into another, which ensures the functioning of the body and the optimal structure of the body for life. The heart pumps blood at high speed and does not stop working, even during sleep. This is very difficult for him. The division of blood into two types, each of which performs its own functions, allows a person to develop and improve. Such a structure circulatory system helps us remain the most intelligent among all creatures born on Earth.

To properly help a person with bleeding, you need to know exactly how. For example, arterial and venous bleeding requires a special approach. Arterial and venous blood are different from each other.

Blood in the human body passes through two circles - large and small. Big circle form arteries, small - veins.

Arteries and veins are connected to each other. Small arterioles and venules branch off from large arteries and veins. And they, in turn, are connected by the thinnest vessels - capillaries. They exchange oxygen for carbon dioxide and deliver nutrients our organs and tissues.

Arterial blood passes through both circles, both arteries and veins. It flows through the pulmonary veins into the left atrium. Carries and then gives oxygen to tissues. Tissues exchange oxygen for carbon dioxide.

Having given up oxygen, a person’s arterial blood, saturated with carbon dioxide, turns into venous blood. She returns to the heart, and then, according to pulmonary arteries, to the lungs. It is the venous one that is taken for most tests. It contains fewer nutrients, including sugar, but more products metabolism such as urea.

Functions in the body

Arterial blood carries oxygen, nutrients, and hormones throughout the body.
Venous, unlike arterial, carries carbon dioxide from tissues to the lungs, metabolic products to the kidneys, intestines, sweat glands. By folding, it protects the body from blood loss. Warms organs that need warmth. Venous blood is flowing not only through the veins, but also through the pulmonary artery.

Differences

The color of venous blood is dark red with a bluish tint. It is warmer than arterial water, its acidity is lower, and its temperature is higher. There is no oxygen in her hemoglobin, carbhemoglobin. In addition, it flows closer to the skin.
Arterial - bright red, saturated with oxygen and glucose. Oxygen in it is combined with hemoglobin to form oxyhemoglobin. The acidity is much higher than in the venous. It comes out to the surface of the skin on the wrists and at the neck. Flows much faster. That's why it's hard to stop her.

Signs of bleeding

Before medical assistance in case of bleeding, this means stopping or reducing blood loss until the ambulance arrives. It is necessary to distinguish between types of bleeding and use it correctly necessary funds to stop them. It is important to have dressings in your home and car first aid kits.

The most dangerous species bleeding – arterial and venous. The main thing here is to act quickly, but do no harm.

At arterial bleeding blood flows in bright scarlet intermittent fountains with high speed in time with your heartbeat.
With venous, a continuous or weakly pulsating dark cherry stream of blood flows from the injured vessel. If the pressure is low, a blood clot forms in the wound and blocks the blood flow.
With capillary, bright blood slowly spreads over the entire wound or flows in a thin stream.

First aid

When providing first aid for bleeding, it is important to determine its type and, depending on this, act.

If an artery in the arm or leg is affected, a tourniquet must be applied above the affected area. While the tourniquet is being prepared, press the artery above the wound to the bone. This is done with a fist or by pressing hard with your fingers. Elevate the injured limb.

Place it under the tourniquet soft cloth. You can use a scarf, rope, or bandage as a tourniquet. The tourniquet is tightened until the bleeding stops. You need to place a piece of paper under the tourniquet to indicate the time of application of the tourniquet.

ATTENTION. For arterial bleeding, the tourniquet can be held for two hours in the summer, and half an hour in the winter. If medical help is still not available, loosen the tourniquet for a few minutes while holding the wound with a clean cloth pad.

If a tourniquet cannot be applied, for example, in case of injury iliac artery, make a tight tampon with a sterile or at least clean cloth. The tampon is wrapped with bandages.

At venous bleeding a tourniquet or tight bandage is applied below the wound. The wound itself is covered with a clean cloth. The affected limb needs to be raised higher.

For these types of bleeding, it is good to give the victim painkillers and cover him with warm clothes.

In case of capillary bleeding, the wound is treated with hydrogen peroxide, bandaged or covered with a bactericidal adhesive plaster. If it seems to you that the blood is darker than a normal wound, then the venule may be damaged. Venous blood is darker than capillary blood. Proceed as if you had damaged a vein.

IMPORTANT. Capillary bleeding is dangerous if blood clotting is poor.

From the right help During bleeding, a person’s health and sometimes life depends.

There's so much you can't find on the net. Even the question about the color of blood and veins is often accompanied by assumptions and fiction, although most people actually know the answer. Yes, everything is simple here - the blood is red, only in different shades, depending on the amount of hemoglobin in it and oxygen enrichment. Everything is as taught in biology and BJD at school: arterial blood(oxygen-rich, coming from the heart) bright scarlet color, A venous(giving oxygen to the organs, returning to the heart) – dark red(burgundy). The veins that are visible under the skin are also red when blood runs through them inside. After all, the blood vessels themselves are quite transparent. But still, many people have questions such as “Why does blood happen? different color and what does this depend on? and “Why are veins blue or cyan?”

The red color of blood can have different shades. Oxygen carriers, i.e. erythrocytes (red blood cells), are tinged red depending on the hemoglobin, an iron-containing protein found in them, which can bind with oxygen and carbon dioxide to carry them to Right place. The more oxygen molecules connected to hemoglobin, the brighter the red color the blood is. That is why arterial blood, which has just been enriched with oxygen, is so bright red. After the release of oxygen to the cells of the body, the color of the blood changes to dark red (burgundy) - such blood is called venous.

Of course, the blood contains other cells besides red blood cells. These are also leukocytes (white blood cells) and platelets. But they're not like that significant amount compared to red blood cells to affect the color of blood.

Blood color in anemia and cyanosis

In fact, of course, although the veins carry dark burgundy blood, unlike the bright scarlet arterial blood, they are not at all blue in color. They are red, like the color of the blood that flows through them. And you shouldn’t believe in the theory that you can find on the Internet that the blood actually runs through the vessels is blue, but when cut and in contact with air it instantly turns red - this is not so. Blood is always red, and why is described above in the article.

The veins only appear blue to us. This is explained by the laws of physics about the reflection of light and our perception. When a beam of light hits the body, the skin reflects some of all the waves and therefore looks light, well, or different, depending on melanin. But it transmits the blue spectrum worse than red. But the vein itself, or rather the blood, absorbs light of all wavelengths (but less, in the red part of the spectrum). That is, it turns out that the skin gives us for visibility Blue colour, and the vein itself is red. But, interestingly, the vein actually reflects even a little more red than the skin in the blue spectrum of light. But why then do we see veins blue or cyan? And the reason, in fact, lies in our perception - the brain compares the color of the blood vessel against the bright and warm tone of the skin, and in the end shows us blue.

Why don’t we see other vessels through which blood flows?

If a blood vessel is located closer than 0.5 mm to the surface of the skin, then it generally absorbs almost all blue light, and reflects much more red - the skin looks healthy pink (ruddy). If the vessel is much deeper than 0.5 mm, then it is simply not visible, because the light does not reach it. Therefore, it turns out that we see veins that are approximately located at a distance of 0.5 mm from the surface of the skin, and why they are blue has already been described above.

Why can't we see arteries from under the skin?

In fact, about two-thirds of the blood volume is in the veins at all times, therefore they bigger size than other vessels. In addition, arteries have much thicker walls than veins, because they have to withstand more pressure, which also prevents them from being sufficiently transparent. But even if the arteries were visible from under the skin as well as some veins, it is assumed that they would have approximately the same color, despite the fact that the blood running through them is brighter.

What color are veins actually?

If you've ever cooked meat, you probably already know the answer to this question. Empty blood vessels are reddish-brown in color. There is not much difference in color between arteries and veins. They differ mainly when viewed in cross section. The arteries are thick-walled and muscular, and the veins have thin walls.

As for aristocrats, the expression “ blue bloods" appeared due to the pallor of their skin. Until the twentieth century, tanning was not in fashion, and the aristocrats themselves, especially women, hid from the sun, thereby protecting their skin from premature aging and looked appropriate to their status, that is, they differed from the serfs who “plowed” all day in the sun. Now we understand that pale color skin with a blue tint is actually a sign of less health.

But scientists also claim that there are about 7,000 people in the world whose blood has a blue tint. They are called kyanetics (from the Latin cyanea - blue). The reason for this is not the same hemoglobin. Their protein contains more copper than iron, which during oxidation acquires a blue tint instead of the red we are accustomed to. These people are considered more resistant to many diseases and even injuries, as their blood is said to clot several times faster and are not susceptible to many infections. In addition, there are different theories about the origin of kianeticians, including that they are descendants of aliens. There is not much information about them on the Internet, but there are articles in foreign publications where the birth of such children is explained by the abuse of rudimentary drugs long before conception. As they say, “Don’t smoke, girl, the children will be green!”, but the results from birth control may turn out blue (meaning the color of blood).