What is body fluid?

Body fluid: The body contains a lot of water, which together with various substances dispersed in water are collectively called body fluid, accounting for about 60% of the body weight. Body fluid can be divided into two parts: intracellular fluid and extracellular fluid. Intracellular fluid in cells accounts for about 40% of body weight. What exists outside the cell is called extracellular fluid. Extracellular fluid is divided into two types: one is interstitial fluid (including lymph and cerebrospinal fluid) existing between tissues and cells, accounting for about 16% of body weight. The other is plasma (about 5% of body weight).

Functional action

Human metabolism is a series of complex biophysical and biochemical reaction processes, which are mainly carried out in cells, and these processes are inseparable from water. The volume, distribution and electrolyte concentration of water in the body are all regulated by the wonderful human body, which makes the volume, electrolyte concentration, osmotic pressure and pH value of body fluid inside and outside the cell relatively stable in dynamic balance.

This balance is a necessary condition for human cell metabolism. It may be destroyed by trauma, infection, improper treatment and bad living habits, which is beyond the adjustment ability of the human body. This can lead to a series of sub-health manifestations, and when it develops to a certain extent, it can become the main factor threatening life.

Extracellular fluids of higher animals include plasma, lymph, cerebrospinal fluid and tissue fluid. Although they are separated from each other and have different components, they are interrelated, and plasma plays a connecting role among various fluids. Because blood circulates in the cardiovascular system, capillaries are all over the body, and its total area is estimated to be about 83 10 square meter. However, only a small part of capillaries in the body are usually open. But it is also enough for physical exchange. When blood flows through the digestive tract and lungs, it gets nutrients from the gastrointestinal tract and oxygen from the lungs. When it flows through the tissues and cells of the whole body, it transports nutrients and oxygen to the cells through the interstitial fluid to meet the needs of the cells. At the same time, the products of cell metabolism enter the blood, are transported to organs such as kidney, lung and skin through circulation, and are discharged from the body, so that the blood is constantly updated, which is one of the important conditions for maintaining the relative stability of the internal environment of the body.