Why do blood vessels look blue under the skin?

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Veins looking Blue It is an optical illusion caused by light reflecting on and through the skin.

Blood in the arteries is bright red, blood in the veins is dark red mostly from the impurities that are being carried back to the kidneys and liver for disposal that are mixed in and brownish which darkens the red color to more maroon. Blood in veins can look "blue" when viewed through the skin because of light refraction and other factors. But the blood is red and the veins are actually white.

When a person donates blood, it comes from a vein, not an artery. It is also not exposed to air, or it would be contaminated and need to be disposed of. It also happens to be dark red, NOT blue.

The common misconception of "blue" blood is continued due to textbook illustrators use of blue and red to differentiate arteries and veins. Venous blood is actually a burgundy or maroon color.

An Optical Illusion
The reason we see blue is more into the optics side of science. It is really because of how light reflects on our skin, and the way different wavelengths piece through our skin with different effectiveness.

The veins you see through your skin appear blue because red light goes through the skin much more easily (and thus more) than blue light. The red light is absorbed, and the blue is reflected. Optical scientists also believe that the eyes see more of the blue color than the red.

A vein is just a tube blood travels through when returning to the heart and lungs after depleted of nutrients and oxygen, the neutral color of a vein itself doesn't change the color of the blood.

It is not the blood but the veins that "look" blue, and even then it is not the actual color of the vessel. The difference is in the way colored light moves through the tissues, and how the eye perceives those colors of light.

The oxidation state of the iron in the hemoglobin also affects the color but only slightly and not as much as the wastes carried in the veins do.

Some factor of the changes in blood coloration do relate to the respiratory pigment, hemoglobin. Hemoglobin is a topologically complex molecule that very readily binds to oxygen. Once the molecule is fully saturated, it reflects in the crimson red spectrum, and therefore fully oxygenated blood appears to be bright red. After the hemoglobin molecule gives up its oxygen to tissue that needs it, the molecule becomes much less reflective, and with the added wastes the venous blood carries, the returning blood appears very dark red to purple. However, it is more the addition of wastes that impacts the darkened color, not so much the change in oxygen content.

As mentioned above, blue is often used in illustrations in charts and diagrams of the circulatory system and vessels to contrast against red, with usually red representing the arterial system bearing O2 and blue being the "deoxygenated" blood in the venous system. However, this tradition of using these colors is just that: tradition. It is not based on actual blood color. The colors could just as easily be shown as yellow or green for the purposes of the illustrations to show blood flow.

The reason why only veins appear blue to your eye is because they are the most superficial to the skin and therefore seen through the skin. Arteries can not be seen because of how deep they are in the body (a protective mechanism of our bodies). The color blue/violet is the highest frequency of the visible light scale; it therefore has the most penetrating power to be seen through skin, fat, etc. Red is low frequency and is filtered out by skin and fat, which is why it cannot be seen.

Science Project: If you took a red diode light and put it in milk, it would appear blue in color because milk filters the red out much like our fat/skin. Try it and see!
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What layer of skin that contains the blood vessels and nerves closest to the surface of of the skin is?

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What is the difference between red and blue blood vessels?

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What does a broken blood vessel look like on the arm?

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Does blood in the deep blood vessels give color to skin?

It depends on how you look at it (pun intended). If you are asking if you can see the blood or blood vessels in deep vessels through the skin, the answer is likely no. It depends on which vessels, how deep they are and how much subcutaneous tissue the person has. If you are asking if the deep ves ( Full Answer )

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This is a process known as vasodilation , which takes place if your core body temperature gets too high. The capillaries just below the epidermis dilate to allow more blood to reach the surface of the skin. The blood carries with it thermal energy, which is then lost by radiation upon reaching the ( Full Answer )

What do broken blood vessels in your leg look like?

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What is a broken Blood vessel under eye look like?

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What does burst blood vessel in leg look like?

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What causes blood under the skin?

, What causes bleeing from under the skin is a bruise. You can tell how bad you're bleeding from under your skin by the color of the bruise. If it's black, you know it's bleeding a lot. If it's yellowy-greeny it's not a major bruise. Bruises can change color. It also depends on how hard you hi ( Full Answer )

Which blood vessels give color to the skin?

The blood vessels I would imagine you mean are the capillaries. These are the very thin blood vessels which run just under the skin and dilate in response to stress or increased body temperature to allow more blood to the surface. This causes flushing of the skin which gives it a reddish colour. Thi ( Full Answer )

Why does the skin of a frog have many blood vessels?

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Why does Blood vessels near the skin regulate heat loss?

Core body temperature is the balance between energy produced in the body and heat loss from the body. The dilation of blood vessels in the skin helps increase the loss heat from the body core to the skin and from there out of the body. Of course if one lived in a climate much warmer than 37 degrees ( Full Answer )

What is the meaning of the blood vessel of the skin?

The blood vessels are the part of the circulatory system that transport blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart ; the capillaries, which enable the actual exchange of water and chemicals between the blood and ( Full Answer )

What causes burst blood vessels under tongue?

It's could be from sucking aggressively on some such as a straw. The blood vessels and tissues in your mouth are very sensitive. Even more so when you're drinking ice cold beverages it causes a numbing sensation and can't tell pain receptors that you're causing yourself injury.

Which blood vessel gives color to the skin?

the capillaries. Pigment of the skin can make the skin look more transluscent causing a person's color to look rosy or show little to no color change at all.

What do you need to get healthy skin and blood vessels?

Raw fruit and veg diet. Throw out everything in the kitchen, get a sharp knife and a chopping board. Buy your fruit and veg along with bottled water. It is allowed to make dressings but from traces of olive oil and vinegar. No dairy whatsoever. No cooking. It has to be like you are foraging for your ( Full Answer )

Is there blood under your skin?

Not free flowing unless you pop a capillary. The blood is carried in arteries to veins and then is distributed through millions of very small vessels called capillary's.

Is it bad to see blood vessels under the skin?

Not at all! These are called varicose veins and they are in no way harmful. Some people do not like the way they look and choose to have laser treatment on them, but they are nothing to worry about.

Why do some of the blood vessels in your wrist look blue?

deoxygenated blood looks slightly purple/blue as the fe^2+ prosthetic groups in the erythrocytes (red blood cells) are not bound to O2. when they are, they appear the colour red that is seen when blood is exposed to the air.

When does blood look blue?

blood isn't blue its only blue because of the light, if you went in a completley dark space it will be red

Which blood vessels have blue blood?

It is not exactly blue it is a very very deep red, and that blood is in all your veins except for pulmonary vein and it is also in your pulmonary artery

Where in the skin do you have blood vessels?

Everywhere, every centemeter of the skin has capillaries that go through it in order to keep the cells alive. Thats why no matter where you get a small cut you will bleed no matter how shallow it is.

Why does blood appear blue under the skin?

Veins are very close to the skin, which allows them to play a role in heat dissipation. Because they are so close to the skin, you are able to easily see them. They appear blue because of the way light diffuses through the skin. It possibly also has to do with the way that subcutaneous fat absorbs l ( Full Answer )

Why are blood vessels have blue and red color?

only the veins are blue because they blood cells have no oxygen so they are heading back to the heart for fresh oxygen and then goes through this progress again. the blood is red because its blood of course.

Why are blood vessels helpful in the skin?

Blood vessels are helpful to the skin because they carry oxygen andnutrients to it. Blood vessels help to keep the skin looking freshand youthful.