The document discusses electrolytes, which are minerals that conduct electricity in body fluids. There are major cations like sodium, potassium, calcium, and magnesium, and major anions like chloride, bicarbonate, phosphate, and sulfate. Electrolytes are either intracellular, primarily potassium, or extracellular, like sodium and chloride. It then provides more details about common electrolytes like sodium, chloride, potassium, calcium, magnesium, phosphate, and bicarbonate, including their roles, levels in intracellular and extracellular fluid, and notes about factors that affect their levels.
6. SODIUM
Major electrolyte in ECF.
Has a major role in controlling water distribution
throughout the body.
Healthy kidneys maintain a consistent level of
sodium in the body by adjusting the amount excreted
in the urine.
7. NOTE
Loss or gain of sodium is usually accompanied by a loss or gain of
water.
Aldosterone causes an increase in salt and water
reabsorption into the bloodstream from the kidney thereby
increasing the blood volume, restoring salt levels and blood
pressure.
Too much sodium (> 145 mEq/L) can adversely affect these
fluid balances and thus contribute to high blood pressure.
8. CHLORIDE
After sodium, the most abundant electrolyte in
serum, with a key role in the regulation of body
fluids, electrolyte balance, the preservation of
electrical neutrality, acid-base status
It works with other electrolytes, such as sodium and
potassium, to help balance acids and bases in your
body.
Assists in maintaining acid–base balance and works
as a buffer in the exchange of oxygen and CO2 in
red blood cells.
9. NOTE
Chloride and bicarbonate concentrations share an inverse
reciprocal relationship during either acidosis or alkalosis.
An increase in chloride causes a decrease in bicarbonate level
(leading to acidosis) and vice versa.
10. POTASSIUM
It helps the body regulate fluid, send nerve signals
and regulate muscle contractions.
98% of the potassium in your body is found in your
cells. Of this, 80% is found in your muscle cells, while
the other 20% can be found in your bones, liver and
red blood cells
11. NOTE
Potassium chloride is the most common mineral salt used to
partially replace sodium chloride in salt substitutes.
ACEI, ARBs, NSAIDS, spironolactone, heparin, etc. can cause
increase potassium level.
12. CALCIUM
Calcium plays a major role in transmitting nerve
impulses and helps regulate muscle contraction
and relaxation, including cardiac muscle.
Essential for bones, helps maintain heart
rhythm, muscle function, etc.
13. NOTE
When vitamin D level is low, the absorption of calcium in the
intestines becomes less, which then causes the level of
calcium in the blood to go down. As a consequence the
parathyroid glands become more active and produce more
PTH that causes calcium to come out of the bones, therefore
weakening the bones.
Calcium can inhibit the iron (Fe) absorption.
Calcium antagonizes the toxic effect of magnesium, and
these ions electrically oppose each other at their sites of
action
14. PHOSPHATE
Necessary for the formation of bone and teeth.
Phosphate is also used as a building block for
several important substances, including those used
by the cell for energy, cell membranes, and DNA
(deoxyribonucleic acid).
15. NOTE
Calcium and phosphate in the body react in
opposite ways: as blood calcium levels rise,
phosphate levels fall.
PTH regulates the levels of calcium and
phosphorus in the blood.
16. MAGNESIUM
Magnesium balance is important in neuromuscular
function. Because magnesium acts directly on the
myoneural junction, variations in the serum level
affect neuromuscular irritability and contractility.
17. NOTE
An excess of magnesium diminishes the excitability
of the muscle cells, whereas a deficit increases
neuromuscular irritability and contractility.
Magnesium produces its sedative effect at the
neuromuscular junction, probably by inhibiting the
release of the neurotransmitter acetylcholine.
19. NOTE
Bicarbonate has an inverse relationship with chloride.
As chloride moves from plasma into the red blood cells
(called the chloride shift), bicarbonate moves back into
the plasma.
Bicarbonate raises the internal pH of the stomach, after
highly acidic digestive juices have finished in their
digestion of food.
