c. Each electrolyte has certain functions in order to help the body maintain
(1) Sodium. As you can see, sodium is the most abundant positive
electrolyte (or cation) in the extracellular fluid and is also present in intracellular fluid.
The main function of sodium is in maintaining normal osmotic pressure.
(2) Chloride. Chloride is the most abundant negative electrolyte (or anion)
in extracellular fluid and is present in intracellular fluid as well. Chloride is essential to
maintain normal osmotic pressure and is found in the stomach fluid.
(3) Potassium. Potassium is the most abundant electrolyte in the
intracellular fluid. Potassium is also required for osmotic pressure but has other vital
functions. Potassium is required to convert dextrose (a sugar) into body energy and is
required as an aid in transmitting nerve impulses within the heart.
(4) Bicarbonate. Bicarbonate helps to maintain the acid-base balance
within the body (see paragraph 2-6).
(5) Phosphate. Phosphate is required for the formation of bones, teeth, and
body enzymes (see paragraph 2-10 for a discussion of enzymes).
Magnesium. Magnesium is essential for the formation of enzymes within
(7) Calcium. Calcium is essential for the formation of bones and teeth.
Calcium is needed to help in blood clotting and in maintaining the rhythm of the heart
d. If a liter of body fluid is lost from extracellular fluids, all the electrolytes must
be replaced along with the water. If a liter of fluid is lost by a severe case of diarrhea,
the electrolytes would be of a different type and amount than those from the
extracellular fluid. Therefore, both the source of the lost fluid and the amount must be
considered when giving replacement fluids.
The body's internal liquid environment is comprised of the body's fluids and the
blood. For proper body functions to continue normally, this internal environment must
be kept constant (homeostasis) and within a very narrow limit. The acid-base balance
of the blood is maintained by the chemical balance between the cations and the anions,
which must be there in a very delicate balance. The cations are sodium (Na ),
potassium (K ), calcium (Ca ) and magnesium (Mg ). The anions are chloride (Cl ),
bicarbonate (HCO3 ), phosphate (PO4 ), and sulfate (SO4 ). The acid-base balance