Animation showing the composition of normal human blood. A donation bag is seen being filled from a donor's vein, before we zoom into the blood in the bag. Most of the blood is plasma (55%), which is mostly water, along with ions (including sodium and chloride) and sugar (glucose). The plasma also contains proteins, including albumin, globulin, fibrinogen and prothrombin. At a larger scale are the blood cells. By far the most numerous of these are red blood cells (erythrocytes), which make up some 99% of the cells in blood. Tiny platelets, which aid clotting, make up less than 0.5% by volume, with the rest of the cells being white blood cells, parts of the immune system that protects the body from pathogens. At the end of the animation, a blood bags shows the separated components in their proportions. This clip is an edited version of K007/1087. |