How does the body regulate water?

Regulating water input and output of the human body involves the process of homeostasis, and organs such as the kidney.
Water input to our bodies comes from drinking fluids or consuming moist foods. Water is also gained as a byproduct of cellular respiration, while water output from our bodies comes from sweating through our skin, exhaling, faeces and urinating.
If a person does not gain much water to their body, the amount of water output will be decreased such as to maintain a water balance in the body. In our bodies, the water concentration among other things must be maintained as constant as possible.
The kidney plays an important role in regulating water in our body, as it controls the water concentration in blood plasma and produces urine. As our blood passes though our kidneys, molecules such as water, glucose, urea and salt are filtered out. Glucose, as well as sufficient water and salt for the body will be reabsorbed into our blood, leaving the remaining water, salt and urea or urine. When the water level of our blood plasma is high, less water will be reabsorbed back into our blood, and the kidney will produce more diluted urine. Likewise, when the water level of our blood plasma is low, more water will be reabsorbed back into our blood and the kidney will produce more concentrated urine.