The blood is the means by which circulating several fundamental chemicals to the body balance. Consumptiom metabolism, control and structural depend on the exchange of various substances with the environment, like oxygen, carbon dioxide, glucose, amino acids and nucleic acids. Is the blood these exchanges are guaranteed. In addition, several defense cells of the organism (macrophages and lymphocytes) are present stop are essential and in the bloodstream for homeostasis. These and many other many defined do make blood a factor of great importance for the living.
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