Blood is a red opaque liquid consisting of plasma and shaped elements. Distinguish between red blood cells (red blood cells), white blood cells (white blood cells) and blood platelets (platelets). In the human body, blood binds each organ, each cell of the body to each other. Blood carries nutrients derived from food in the digestive system. It delivers oxygen from the lungs to the cells, and carries carbon dioxide, harmful, waste substances to those organs that render them harmless or excreted.
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.