The lower boundary of the exosphere is called the exobase. It is also called exopause and 'critical altitude' as this is the altitude where barometric conditions no longer apply. Atmospheric temperature becomes nearly a constant above this altitude.
Sodium â the volatility and solvent mineral: essential to life, all body fluids contain sodium â itâs needed for many biochemical processes including water balance regulation, fluid distribution on either side of the cell walls, muscle contraction and expansion, nerve stimulation and acid-alkaline balance.
The kidneys maintain our body's water balance by controlling the water concentration of blood plasma. The kidneys also control salt levels and the excretion of urea. Water that is not put back into the blood is excreted in our urine.