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.
1 They eliminate waste products such as broken down proteins from the blood. 2  They remove excess water from the body. 3  They regulate body acid levels.  They maintain the proper chemical and water balance by removing excess minerals and fluid from the body.