2. Water flows endlessly between blood vessels and cells, delivering oxygen and nutrients to tissues and cells, and then discharging metabolic wastes from the body. In short, people's various metabolic and physiological activities are inseparable from water;
3. Water has a certain effect on body temperature regulation. When people breathe and sweat, they will excrete some water. For example, in the hot season, the ambient temperature is often higher than the body temperature, so people rely on sweating to evaporate some heat to lower their body temperature and avoid heatstroke. In cold weather, because of the great potential of water to store heat, the body temperature will not fluctuate obviously because of the low external temperature.
Water is still the lubricant in the body. It can moisturize the skin. When the skin is short of water, it will become dry, lose elasticity and look old. Some joint capsule fluid and serosa fluid in the body can prevent organs from being damaged by friction and can rotate flexibly. Tears and saliva are also lubricants for corresponding organs.