The internal environment of the body is blood, tissue fluid and lymph. Blood moves through a system of closed vessels and does not directly contact tissue cells. Tissue fluid is formed from the fluid part of the blood. She got this name because she is among the tissues of the body. Nutrients from the blood enter tissue fluid and cells. Decomposition products move in the opposite direction. Lymph. Excess tissue fluid enters the veins and lymph vessels. In the lymphatic capillaries, it changes its composition and becomes lymph. Lymph moves slowly through the lymphatic vessels and eventually enters the bloodstream again. Preliminarily, the lymph passes through special formations – the lymph nodes, where it is filtered and disinfected, enriched by the lymph cells.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.