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.
water balance. 1  The kidneys match renal excretion to intake of water and electrolytes to regulate the osmolality and volume of body fluids. Deficits of water or electrolytes can be compensated for by increases in intake and retention, whereas excesses are compensated for by increases in urinary excretion.