What is bloods natural colour?

Question

Our blood is blue when it leaves our heart. It goes to the lungs and turns red because of the oxygen that is there. The arteries take the oxygenated blood to our tissues and organs. The blood is now de-oxygenated and is therefore blue. So what is our natural colour? blue or red blood?

Answer 1

well, blood is actually a composition of many ingredients. red blood cells are red, white blood cells are clear or whitish, platelets are tiny fragments of cells, and blood plasma is a clear liquid.

i'm not sure you are right when you say that blood is blue when it leaves the heart. i've never really heard of blue blood before but you could be right. i don't know about that.  

Answer 2

Depends on where it is in your circulatory system.  

Answer 3

human blood is blue with out oxygen but when it hits oxygen its red

Answer 4

purple, means it is exposed to a tiny bit of air

Answer 5

BLOOD'S NATURAL COLOUR is red that is caused by hemoglobin..so basically ..it is red

Answer 6

blue, because the redness is the chemical reaction between the blood and the oxygen

Answer 7

blue, once it hits oxygen it becomes red, from the red blood cells.

Answer 8

blue you dumbass!

Answer 9

your natural blood is a purple-ish blue color. and when it gets exposed to oxygen it turns red.  

Answer 10

blue

Answer 11

Blood is NEVER blue.

When it is oxygenated, it is bright red, and when it is deoxygenated is is a darker red - but it is never blue!

It is shown as blue in diagrams of the circulatory system for illustrative purposes.

And your veins *appear* blue through your skin because of pigments in their walls, and in the overlying skin and fat layers.

Answer 12

MANY people claim that there is blue blood in our bodies, but thats just   what the pictures in text books show so they dont confuse us. Sometimes the blood looks blue under our skin but it is ALWAYS red...Summary: they more oxygen, the brighter color blood is

Answer 13

Blood is NEVER blue. This is a pet peeve of mine. A LOT of people think this for some reason but it always appears red.

Blood is composed of a few things:

-Red blood cells (erythrocytes)

-White blood cells

-Platelets

-Plasma (what everything "floats" in; plasma is mainly water)

-Plasma proteins (e.g. albumin)

In comparison to the other material in the blood plasma, red blood cells are the most plentiful. A single drop of blood contains millions of red blood cells.

Each red blood cell is composed of millions of haemoglobin molecules (~300million per RBC) and at the center of each haemoglobin is an atom of iron. This is why red blood cells appear red.

Heamoglobon is the pigment which binds oxygen for transport throughout the body. When oxygen is bound the RBC Appears a light red. When oxygen is not bound it (and is replaced by carbon dioxide) it appears a darker shade of red, almost a burgundy color . But at no point is the blood blue.

But the fact is that the blood's color is not the main contributing factor to the reason we see blue veins.

ANSWER:

To answer this question you have to first understand how we see anything at all. When we look at something, pigments in the object we are looking at absorb some of the colors while reflecting others. The colors that are not absorbed, but instead reflected back to our eye, is the color we see.

In order for us to see any color at all of our veins, even if it was green yellow purple red blue or what have you, the light first has to reach the vein itself. To do that it has to pass though the skin, hit the vein then pass back though the skin and into our eye. Now, I'm sure most of you would agree that our skin has color pigments; that it is not transparent but rather translucent. Because of these pigments light is not only absorbed when hitting the vein, but also when entering/leaving the skin. I guess in a way you could think of it this way: your skin over your blood vessel acts like a piece of colored plastic, the kind you might find in 3D glasses. Lets say you take out the blue plastic from 3D glasses and look though it. When looking through the plastic things you KNOW aren't blue appear to be blue. You skin acts very similar to this; light passing though the skin is absorbed and only the higher intensity wavelengths make it to your eye. These high intensity wavelengths of light are what our eyes interpret as 'blue'.

Some of you may be thinking now "Well if this is all true, why doesn't all the skin look blue?" You'll notice that the places that you see blue veins are in areas where the skin is thin and the blood vessel underneath is pushing up on it stretching the skin over it. Light hitting the dark color of the vein underneath the skin, in combination with the skin itself is what causes it to appear blue in these areas.

In short, it is not your vein that is blue but rather it is your skin with the shallow dark vessel underneath.

-Note- Some invertebrates do have blue "blood" but this is because they lack the chemistry we have making up our blood, specifically Iron-centered heamoglobin molecules of the red blood cells.

I realize this was a huge post, but it needed to be said. If you read all the way though it, props to you!