Human venous blood is different from arterial blood. What is the difference between arterial and venous blood

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

As you know, blood is venous and arterial.

Arterial oxygenated in the lungs.

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

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

The color and density of blood concepts are several from different planes. The color is due to the saturation of the blood with oxygen and the number of red blood cells. Density is manifested in the folding of the protein. Looks like platelets are involved.

Blood from a vein is black 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 already become brighter.

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

Venous blood always has a very dark, almost black hue. 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, the color also changes.

Humans have both venous and arterial blood. Accordingly, the arterial is bright red, as it is saturated with oxygen. Venous blood is dark in color, since its function is to saturate with carbon dioxide.

This is the normal state. Venous blood is poor in oxygen and saturated with carbon dioxide. And the color of blood and its density are in no way related concepts. Do not worry about this - everything is fine with you.

The density of blood has nothing to do with its color. Whether the blood is thicker or more liquid depends on the degree of coagulation, and this, in turn, on the amount of protein. The color also indicates the saturation of the blood with oxygen. It is because of this that arterial blood in the light is much lighter than venous blood.

When I went in for sports, we often took blood for tests in a physical dispensary (the medical commission was regular and mandatory), then I discovered this oddity and asked the doctor, he says everything is fine, venous blood without oxygen(well, almost) from here and the color.

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

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

The human body has both arterial and venous blood. And venous blood is different in color, it is darker, it has little oxygen. But the blood from the artery is bright red, because it is well oxygenated.

Venous blood contains carbonic acid, which gives it a dark color.

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 their way back when they have already delivered oxygen to the capillaries and in return they have taken in carbon dioxide for delivery to the exchanger, that is, to the lungs.

Finally, about the density of the blood, which depends on its viscosity and is caused by; formed elements of blood cells and they increase the density. And the second is density-lowering plasma. The imbalance between the formed elements of the plasma is the cause of the blood condition.

Everything, Khan to you, you become a vampire! Joke. And what should she be? Venous blood is always very dark, almost black in some people. This is due to the fact that in the venous blood there is almost no oxygen and a lot of carbon dioxide. This is what makes her dark. It will pass through the lungs, it will become bright scarlet, arterial.

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

Everyone knows that blood is venous and arterial. In this article, you will find out through which vessels darker blood moves, find out what is included in this biological fluid.

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

The blood, which has given away all the useful substances, flows first to the right half of the heart, and then to the pulmonary circulation. There, it, enriched with 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 separated by the atrial septum, and the ventricles by the interventricular septum. The weight of the human "motor" is from 250-330 grams.

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

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: "Which vessels carry venous blood?" simple. Venous blood is carried exclusively by the pulmonary artery.

The arterial wall consists of several layers, these include:

• outer connective tissue sheath;
• middle (it is made up of smooth muscles and elastic hairs);
• internal (consisting of connective tissue and endothelium).

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

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

For the first time, Dr. V. Harvey wrote about blood circulation back in 1628. The circulation of biological fluid occurs through the small and large circles of blood circulation.

The movement of biological fluid in a large circle starts from the left ventricle, due to increased pressure, the blood spreads throughout the body, nourishes all organs with useful substances and takes away harmful ones. Further, the transformation of arterial blood into venous blood is noted. The last stage is the return of blood to the right atrium.

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

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

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

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

It has little oxygen, but at the same time it is rich in metabolic products. She is more viscous. This is due to an increase in the diameter of red blood cells due to the intake 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). Veins in the human body are much larger than arteries.

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

What color is the blood in the veins you know. The hue of the 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 it (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.

It is at least unreasonable to believe in the theory that 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.

The veins can only appear bluish, this is due to the simple laws of physics.. When light hits the body, the skin beats off part of all the waves and therefore looks light, well, or dark (depending on the concentration of the coloring pigment).

What color is venous blood, you know, now let's talk about the composition. It is possible to distinguish arterial blood from venous blood using laboratory tests. Oxygen tension - 38-40 mm Hg. (in the venous), and in the arterial - 90. The content of carbon dioxide in the venous blood is 60 millimeters of mercury, and in the arterial - about 30. The pH level in the venous blood is 7.35, and in the arterial - 7.4.

The outflow of blood, which carries away carbon dioxide and metabolic products, 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 ZhVS.

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

The blood flowing through the veins overcomes "difficulties" during movement, which include pressure and gravity. That is why, in case of damage, the biological fluid flows in a slow stream. But in the event of an injury to the arteries, blood spurts out in a fountain.

The speed at which venous blood moves is much less than the speed at which arterial blood moves. The heart pumps out blood at high pressure. After passing through the capillaries and turning into a venous, there is a decrease in pressure to ten millimeters of mercury.

Why venous blood is 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 probably noticed that blood is taken from a vein for analysis, and you 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. Due to their presence, a pathological process can be detected.

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

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

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

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

Capillary bleeding can open even with minimal injury. The blood flows out calmly, in a small trickle. Such damage is treated with green paint. Next, a bandage is applied to them, which helps to stop bleeding and prevent pathogens from entering the wound.

As for the venous, when damaged, the 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.

With regards to arterial, it is the most dangerous. If an injury has already happened and you see that bleeding from an artery, you must immediately raise the limb as high as possible. Next, you need to bend it, pinch the wounded artery with your finger.

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

Bleeding is dangerous and fraught with severe blood loss and even death. That is why in case of injury it is necessary to call an ambulance or take the patient to the hospital on your own.

Now you know why the blood in the veins is darker than arterial. The 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 around the body, which is necessary for blood circulation. The main difference between venous and arterial blood is that it has a higher temperature and contains fewer vitamins and minerals.

Arterial blood flows in capillaries. These are the smallest points on the human body. Each capillary carries a certain amount of fluid. The entire human body is divided into veins and capillaries. There is a certain kind of blood flowing there. Capillary blood gives a person life and provides oxygen throughout the body and most importantly in the heart.

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

Venous blood is blue-red in color, contains metabolic products, flows through veins with very thin walls. It withstands high pressure, because the heart at the time of contraction can form drops that the vessels must withstand. The veins are located above the arteries. They are easy to see on the body and easier to damage. On the other hand, venous blood is thicker than arterial blood and flows out more slowly.

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

There is a large and small circles of blood circulation. In a small circle, the fluid is saturated with carbon dioxide and flows to the lungs from the heart. It leaves the lungs, having been saturated with oxygen, and enters a large circle. From the lungs to the heart runs blood based on carbon dioxide, through the capillaries of 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 side. During the contraction of the heart, arterial blood enters the aorta. It is the main vessel of the body. From there, oxygen enters down and ensures the functioning of the legs. The aorta is the most important artery for humans. She, like her 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, blood from a vein is not difficult to take, because it flows worse than a capillary, so a person will not lose much blood during the operation. The largest human arteries cannot be damaged at all, and if necessary, an examination of arterial blood is taken from the finger to minimize negative consequences for the body.

Venous blood is used by doctors to prevent diabetes. It is necessary that the level of sugar in the veins does not exceed 6.1. Arterial blood is a clear liquid that flows throughout the body, nourishing all organs. Venous absorbs the waste products of the body, cleaning it. Therefore, it is by this type of blood that human diseases can be determined.

Bleeding can be external and internal. The internal is more dangerous for the body and occurs when human tissues are damaged from the inside. Most often, this occurs after a very deep external wound or a malfunction in the body that has led 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 is due to the fact that too little oxygen is supplied to the brain. Venous blood can be lost due to internal bleeding and it will be harmless to a person, while arterial blood is not. Internal bleeding quickly blocks brain function due to lack of oxygen. With external bleeding, this will not happen, because the connection between human organs is not broken. Although, the loss of a large amount of 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 blue and arterial red. The venous is rich in carbon dioxide, and the arterial is rich in oxygen. Venous flows from the heart to the lungs, where it turns into an arterial, saturated with oxygen. Arterial flows through the aorta from the heart throughout the body. Venous blood contains metabolic products and glucose, arterial blood is more salty.

Arterial blood is located on the left in the heart, venous on the right. The blood must not mix. If this happens, it will increase the load on the heart and reduce the physical capabilities of a person. In lower animals, the heart consists of one chamber, which inhibits their development.

Both types of blood are very important for a person. One feeds it, and the other collects harmful substances. In the process of blood circulation, blood passes one into another, which ensures the functioning of the body and the structure of the body that is optimal for life. The heart pumps blood at a tremendous speed and does not stop working, even during sleep. It's very hard 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 of the circulatory system helps us to 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. The large circle is formed by the arteries, the small circle by the veins.

Arteries and veins are connected to each other. Small arterioles and venules depart from large arteries and veins. And they, in turn, are connected by the thinnest vessels - capillaries. It is they who change oxygen to carbon dioxide, deliver nutrients to our organs and tissues.

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

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

Functions in the body

• Arterial blood carries oxygen, nutrients, and hormones throughout the body.
• Venous, unlike arterial, carries carbon dioxide from the tissues to the lungs, metabolic products to the kidneys, intestines, and sweat glands. Curling, protects the body from blood loss. Warms the organs that need warmth. Venous blood flows 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, 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, glucose. Oxygen in it is combined with hemoglobin to form oxyhemoglobin. The acidity is much higher than in the venous. It comes to the surface of the skin on the wrists, at the neck. It flows much faster. That's why it's hard to stop her.

Signs of bleeding

First aid for bleeding is stopping or reducing blood loss before the arrival of an ambulance. It is necessary to distinguish between types of bleeding and correctly use the necessary means to stop them. It is important to have dressings in the home and car first aid kits.

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

• With arterial bleeding, blood flows in bright scarlet intermittent fountains at high speed in time with the heartbeat.
• With venous - a continuous or weakly pulsating dark cherry blood stream 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 throughout the wound or flows in a thin stream.

First aid

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

• If the artery of the arm or leg is affected, it is necessary to apply a tourniquet above the site of the lesion. While the tourniquet is being prepared, press the artery above the wound against the bone. This is done with a fist, or by pressing hard with your fingers. Raise the wounded limb.

Place a soft cloth under the tourniquet. As a tourniquet, you can use a scarf, rope, bandage. The tourniquet is tightened until the bleeding stops. Under the tourniquet you need to put a piece of paper with the time the tourniquet is applied.

ATTENTION. With arterial bleeding, the tourniquet can be kept in the summer for two hours, in the winter for half an hour. If medical attention is still not available, relax the tourniquet for a few minutes, covering the wound with a clean cloth swab.

If a tourniquet cannot be applied, for example, when the iliac artery is injured, a tight swab is made sterile or at least a clean cloth. The tampon is wrapped with bandages.

• With venous bleeding, a tourniquet or tight bandage is applied below the wound. The wound itself is closed with a clean cloth. The injured limb must be elevated.

With these types of bleeding, it is good to give the victim an anesthetic 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 you think the blood is darker than a normal wound, then the venule may be damaged. Venous blood is darker than capillary blood. Proceed as if the vein was damaged.

IMPORTANT. Capillary bleeding is dangerous with poor blood clotting.

The health and sometimes the life of a person depends on the right help during bleeding.

What you will not find on the net. Even the question of the color of blood and veins is often accompanied by assumptions and fiction, although most people actually know the answer to it. Yes, everything is simple here - the blood is red, only of different shades, depending on the amount of hemoglobin in it and oxygen enrichment. Everything as biology and BJD teaches at school: arterial blood(rich in oxygen coming from the heart) bright scarlet color, A venous(given oxygen to the organs, returning to the heart) - dark red(burgundy). The veins that are visible from 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 come in different colors and what does it depend on?” and "Why are veins blue or blue?".

The red color of blood can have different shades. Oxygen carriers, that is, red blood cells (red blood cells), have a shade of red depending on hemoglobin, an iron-containing protein in them that can bind with oxygen and carbon dioxide to carry them to the right place. The more oxygen molecules attached to hemoglobin, the brighter the red color of the blood. Therefore, 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, there are other cells in the blood besides red blood cells. These are also leukocytes (white blood cells) and platelets. But they are not in such a significant amount compared to red blood cells to affect the color of the 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 by no means blue in color. They are red, like the color of the blood that flows through them. And do not believe in the theory that can be found on the Internet that the blood actually runs through the vessels is blue, and when cut and in contact with air it becomes instantly 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 due to the laws of physics about the reflection of light and our perception. When a beam of light hits the body, the skin beats off part of all the waves and therefore looks light, well, or different, depending on melanin. But she misses the blue spectrum worse than the red one. 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 a blue color for visibility, and the vein itself - red. But, interestingly, in fact, the vein reflects even a little more red than the skin of the blue spectrum of light. But why then do we see veins blue or light blue? And the reason, in fact, lies in our perception - the brain compares the color of a blood vessel against a bright and warm skin tone, and as a result shows us blue.

Why do we not see other vessels through which blood flows?

If the blood vessel is closer than 0.5 mm to the skin surface, then it generally absorbs almost all blue light, and beats off much more red light - 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 the veins, which 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 volume of blood is in the veins at all times, hence they are larger 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 is the actual color of a vein?

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. Arteries are thick-walled and muscular, while veins have thin walls.

As for the aristocrats, the expression "blue blood" appeared due to the pallor of their skin. Until the twentieth century, tanning was not in vogue, and the aristocrats themselves, especially women, hid from the sun, which saved their skin from premature aging and looked according to their status, that is, they differed from serfs who “plowed” all day in the sun. It is now we realize that pale skin with a blue tint is actually a sign of lesser 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 lat. cyanea - blue). The reason for this is not such hemoglobin. In them, this protein contains more copper than iron, which, during oxidation, acquires a blue tint instead of the usual red for us. These people are considered to be more resistant to many diseases and even injuries, as they say that their blood clots several times faster and is not exposed to many infections. In addition, there are various theories about the origin of Kyanetics, including that they are descendants of aliens. There is not much information about them on the net, but there are articles from foreign publications where the birth of such children is explained by the abuse of contraceptive drugs long before conception. As they say, “Don’t smoke, girl, the children will be green!”, And it can turn out blue from contraceptives (meaning the color of blood).