Why is our blood color red 1

Why is our blood actually red?

Since the white blood cells, the leukocytes, and the blood platelets, the thrombocytes, are only visible under the microscope and blood plasma is a clear, yellowish liquid that consists of 90% water, only one blood component remains for the red one Color of blood left over.

As the name suggests, the red blood cells, the erythrocytes, are responsible for the red color of our blood because they contain the red pigment hemoglobin.

Hemoglobin binds oxygen and carbon dioxide, which are essential for us. Since oxygen and carbon dioxide are difficult to dissolve in water, the gases need a “carrier”, hemoglobin, to move them through our body. When the blood flows through the small blood vessels in the lungs, the inhaled oxygen is bound to the hemoglobin, transported to the cells and released there. While the carbon dioxide is partly absorbed by the hemoglobin and transported back to the lungs, where we ultimately exhale it.

Our organism is only optimally supplied with oxygen if there is enough iron in the blood.

The hemoglobin in the blood is not only responsible for the typical red color. It is the most important part of the red blood cells (erythrocytes). These have the task of supplying all body cells with vital oxygen and removing carbon dioxide as a metabolic end product on the way back to the lungs. Oxygen and carbon dioxide are transported with the help of hemoglobin. Hemoglobin contains iron, which binds oxygen.

Red blood cells have a lifespan of 100 to 140 days; H. older erythrocytes are constantly being broken down and new ones are being added. A total of around 1.2 liters of new blood are formed each month. The iron contained in the red blood pigment (hemoglobin) is almost completely used again to build new hemoglobin. Every healthy person has a natural iron reserve with which losses can normally be quickly compensated for. If necessary, the formation of new red blood cells increases up to 15 times the normal value.

In the case of a blood donation or greater blood loss, iron that is important for the rebuilding of hemoglobin is lost. If a donor has too little red blood pigment, i. H. if his hemoglobin value is too low or at the lower limit, he does not have sufficient iron reserves for an increased formation of fully functional erythrocytes. A blood donation is then not possible at this point.