Blood
From Wikipedia, the free encyclopedia
For other uses, see Blood (disambiguation).
Human blood smear:
a β erythrocytes; b β neutrophil;
c β eosinophil; d β lymphocyte.
A scanning electron microscope (SEM) image of a normal red blood cell, a platelet, and a white blood cell.
Blood circulation:
Red = oxygenated
Blue = deoxygenated
Human blood magnified 600 times
Frog blood magnified 600 times
Fish blood magnified 600 times
Blood is a specialized bodily fluid that delivers necessary substances to the body's cells β such as nutrients and oxygen β and transports waste products away from those same cells.
In vertebrates, it is composed of blood cells suspended in a liquid called blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (90% by volume),[1] and contains dissolved proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), platelets and blood cells themselves. The blood cells present in blood are mainly red blood cells (also called RBCs or erythrocytes) and white blood cells, including leukocytes and platelets. The most abundant cells in vertebrate blood are red blood cells. These contain hemoglobin, an iron-containing protein, which facilitates transportation of oxygen by reversibly binding to this respiratory gas and greatly increasing its solubility in blood. In contrast, carbon dioxide is almost entirely transported extracellularly dissolved in plasma as bicarbonate ion.
Vertebrate blood is bright red when its hemoglobin is oxygenated. Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, instead of hemoglobin. Insects and some molluscs use a fluid called hemolymph instead of blood, the difference being that hemolymph is not contained in a closed circulatory system. In most insects, this "blood" does not contain oxygen-carrying molecules such as hemoglobin because their bodies are small enough for their tracheal system to suffice for supplying oxygen.
Adrian_The_BEAST responding to a
comment by Joe Borfo
07.27.10 - 4:35 pm
reply
Huh. Do you have a source for that information? Because it doesn't seem to make any sense.
I'm not a doctor or anything, but my understanding is that immunity is maintained by "memory cells" that have been exposed to a virus/vaccine, and these cells can still produce antibodies long after the virus/vaccine has left the system. Since plasma is basically everything
but the blood cells, it seems like that immunity would stick around, right?
nathansnider responding to a
comment by Girl Power
07.28.10 - 12:00 am
reply
yeah, nathan, go talk to your Doctor before you
sale your plasma and
loose your vaccine
It's just like if you have been vaccinated for H1N1 and you crash on your bike and loose some of your blood, then you'll need to be vaccinated again.... so keep the vaccine in you at all times; don't loose it.
GIRL POWER STRIKES!!!
md2 responding to a
comment by Girl Power
07.29.10 - 12:56 pm
reply
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Ridazz Roulette!
see
HOLY HEMOGLOBIN, BATMAN!