|Is there any blue blood in our bodies at any time?
Or is it all red with different shades?|
No there is not any blue blood in our body at any
time. The reason that blood veins can appear blue
is due to an “optical illusion” in which the
light absorbed and reflected by the skin and blood
makes the veins appear blue. In the Medieval
era, nobility were referred to as “blue bloods”
because their blue veins were easier to see than
the peasants who worked outside all day and had
tanner skin. The characteristic red color of
blood is due to the complex formed between iron,
oxygen and the protein hemoglobin. When the
hemoglobin and iron don’t have oxygen, the blood
is a deep red color and when they do have oxygen,
the blood is the bright red color that most people
recognize as blood. There are organisms with blue
blood such as horseshoe crabs. These crabs have
blue blood because instead of iron, they have
copper in their blood.
When I was looking into this I actually found a
similar answer on ScienceLine already.
Answer 1 is fantastic and I couldn't hope to do
a better job answering.
Blood in your body is always red. There's a
misconception that some blood is blue when it is
de-oxygenated, or without oxygen, but it is always
red - just a different shade of red. When you look
at your arms, your veins seem bluish-green because
the light that bounces off other tissues and skin
make the blood in your veins appear that way.
Yes. Veins carry "blue" blood.
Blood contains a compound called hemoglobin.
Hemoglobin is like a train, which collects
people from a place and drops them in a different
place. Likewise, hemoglobin collects Oxygen
from the lungs and brings it to all the cells in
the body. Hemoglobin in the lungs binds to oxygen
forming hemoglobin+Oxygen compound, which is
bright red in color. This is why the blood is red
- because of oxygenated hemoglobin. The blood
vessels (channels to carry blood) carrying
oxygenated blood are the "arteries".
When the oxygenated hemoglobin reaches the
cells, it gives up its Oxygen. Its job is not done
yet. There is another transport function
hemoglobin plays, which is to transport the waste
product of cells, namely carbon dioxide
(CO2), to the lungs for breathing its
out. To perform this, hemoglobin combines with
CO2 to form a compound that is blue in
color. The blood vessels that carry hemoglobin+CO2
are called "veins". This is why veins are bluish
in color. But not all CO2 is transport
through hemoglobin; some get transported as
bicarbonates (salts) and some as just
This question is related to a slightly different
one - Why is blood red?Inside of your red
blood cells, a complex of a globular protein
(globin) and a heme group form "hemoglobin." The
heme group binds to iron. Iron in its oxygenated
form has a reddish color - so when your blood has
a lot of oxygen in it, it is bright red. Now think
about your circulatory system - when blood is
being pumped through the lungs, the hemoglobin is
picking up lots of oxygen - and it is bright red
in the arteries. As oxygen is depleted, the blood
is darker red (this would be in your veins)
because the iron is less oxidized. Human blood
is never "blue" even though many of our veins are
bluish in color - that color comes from the
way light is reflected through the skin. There are
other organisms whose hemolymph does have varying
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