Engage My Brain

Is blood really red? Yes, but it's not solid red. If you look at blood under a microscope, you will see four different parts: plasma, red blood cells, white blood cells and platelets. Plasma is a yellowish-white liquid. In the plasma are the red blood cells, the white blood cells and the platelets. Proteins, minerals, digested food and wastes are also found in the plasma.

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Red blood cells make up the greatest part of the blood. Your blood has eighteen billion red blood cells in it! They have a protein called hemoglobin in them, and this is what gives them their red color. Hemoglobin contains iron, and iron likes to combine with oxygen. When oxygen mixes with iron, it produces a red color. The more oxygen iron has in it, the redder it is.