Human blood is mainly two components, one is the blood cells, including white blood cells, red blood cells and platelets, in addition to the cells in the blood, the remaining components add up, the liquid components are called plasma. Plasma contains very rich substances, mainly has many functions, common the following points: 1, the human body’s buffer, that is, to ensure that the intravascular and extravascular, and intracellular and extracellular body energy, and electrolytes, nutritional balance; 2, buffer pair, plasma has a reasonable degree of acidity and alkalinity, to ensure that people in the appropriate acid-base environment, to play a normal physiological function; 3, in addition to blood cells, all the components are counted Plasma, so there are also nutritional functions, such as cities or countries that rely entirely on river transportation, plasma is river water, all the nutrients and substances need to be transported by plasma to reach where they are needed; 4, to ensure the fluidity of the blood, if the flow does not move, embolism will be formed; 5, there is a hemostatic function, to ensure a reasonable hemostatic function, once the blood vessel rupture or other trauma later, the plasma to play the coagulation function.