知识百科：为什么血是红的
我们的血为什么是红色的?是什么东西给它染了色?看了下面这篇文章,你就能了解一些了。The blood flowing through thearteries,capillaries, andveinsof our bodies
contains many different materials and cells, each with a different
function.Plasma, the liquid portion of the blood, comprises more than half of
the blood. Plasma is light yellow in color, and is thicker than water, because
it contains many substances, in addition to the actual blood cells. These
substances include proteins, antibodies that combat disease,fibrinogenthat helps
blood clot,carbohydrates, fats, salts, and others.
Red blood cells, orcorpuscles, encased in blood vessels, color the blood.
Since there are about 35 trillion of these tiny, round, flat discs circulating
in one's body at any one time, their sheer number necessarily lends their red
color to the blood.
As the young red blood cell matures, and takes on an adult form in the
marrow of the bone, it loses its nucleus, and it increases its production
ofhemoglobin. Hemoglobin is the red pigment, or color of blood, and contains
iron, combined with protein.
When blood passes through the lungs, oxygen piggybacks on the hemoglobin of
the red cells. From there, the red cells carry the oxygen through the arteries
and the capillaries to all other cells of the body. Carbon dioxide from the body
cells returns to the lungs through the veins in the same manner, by attaching to
the hemoglobin.
Red blood cells have a life expectancy of approximately four months, before
they are broken up, primarily in the spleen, and are replaced by new red blood
cells. New cells are continuously generated to replace the old cells that have
past their prime, and have been destroyed to make room for the younger
generation.
Let's not forget that, in addition to red blood cells, we also have several
types of white blood cells!
arteries 动脉
capillaries 毛细管
veins 纹理
plasma 血浆
fibrinogen 纤维蛋白原
carbohydrate 碳水化合物
corpuscles 触觉小体
hemoglobin 血色素
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