Blood looks as if it is solid red, but it really is not. If you look at blood under a microscope, you will see that it is made up of four different parts: plasma, red blood cells, white blood cells, and platelets.
The plasma, which is the actual fluid, is a yellowish-white liquid. It contains the red blood cells, the white blood cells, and platelets, along with proteins, minerals, digested food, and wastes.
However, there are more red blood cells in the blood than any of these other substances, and it is the hemoglobin, a red pigment, in the red blood cells that gives your blood its color.
Your blood has 18 billion (18,000,000,000) red blood cells in it!
