(1)
Certain compounds can be formed by combining these charged cations
and anions.
(a)
To form magnesium chloride:
+
Each ion of magnesium has two positive charges (Mg 2). There are 3 mEq of
magnesium in each liter of extracellular fluid. Therefore, each liter of
+
+
extracellular fluid has 6 positive ions of magnesium ( 2 x 3 = 6) available to
combine with other negative ions. If the compound, magnesium chloride is
needed, these six positive ions could combine with six negative ions from the
100 mEq of chloride contained in a liter of extracellular fluid (each electrolyte of
chloride has one negative charge, shown as Cl ). This would yield the required
magnesium chloride by neutralizing the positive and negative ions.
(b)
To form sodium bicarbonate:
+
Each ion of sodium has one positive charge (Na ). There is one negative
charge of bicarbonate (HCO3 ) in each ion of bicarbonate. If the compound,
sodium bicarbonate is required, each positive sodium ion can combine with a
negative bicarbonate ion to yield the required amount of sodium bicarbonate.
This neutralizes the positive and negative ions of both the sodium and the
bicarbonate used.
(2) When the body loses fluids, the number and kind of electrolyte(s) lost
will depend on whether the fluid has been lost from interstitial or intravascular spaces or
both.
b. Intracellular fluid contains the following kinds and amounts of electrolytes per
liter:
+
Potassium (K )
160 mEq
Phosphate (PO4 3)
110 mEq
+
Magnesium (Mg 2)
25 mEq
+
Sodium (Na )
5 mEq
Chloride (Cl )
3 mEq
MD0564
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