CC SPH EXAM 5 (ELEC)

sodium

major extracellular cation

potassium

major intracellular cation

Chloride

major extracellular anion

extracellular cation

calcium is a

intracellular cation

magnesium is an

14%, 1%

phosphorous is __ intracellular, _ extracellular

Na, K, Cl

for volume and osmotic pressure

K, Ca, Mg

For myocardial rhythm and contractility

Ca, Mg, Zn, Cl

Important cofactors in enzyme activation

Na, K

for the regulation of adenosine triphosphatase ion pumps

K, Ca, Mg

for neuromascular excitability

Mg and PO4

for the production and use of ATP from glucose

HCO3, K, Cl

Maintenance of acid-base balance

Mg

replication of DNA and translation mRNA

Sodium

–Largest constituent of plasma osmolality.

–Major role is the regulation of water balance in the body

–Contributes to osmotic pressure in compartments outside the cell and regulates blood pressure

Sodium

–Movement  of  ___ into  the  neuron  is a  major  factor  in the  process  of nerve transmission.

Depletional hyponatremia-

•can be due to diuretics, hypoaldosterism (Addisons disease), diarrhea or vomiting and severe burns or trauma.

dilutional hyponatremia

due to overhydration, syndrome of inappropriate anti-diuretic hormones SIADH), CHF, cirrhosis and nephrotic syndrome.

hyponatremia

•occurs when water is lost as through diarrhea, excessive sweating, or diabetes insipidus and when sodium is retained as through acute congestion, hyperaldosterism or infusion of   hypertonic solutions during dialysis.

potassium

–The single most important analyte in terms of an abnormality being immediately life threatening.

hemolysis, EDTA contamination, prolonged torniquet, excessive squeezing, excessive fist clenching, thrombocytosis, severe leukocytosis

false increase in K+

hypokalemia

results from decreased dietary intake, hyperaldosterism, diuretics, vomiting, diarrhea, laxative abuse, and excess insulin which causes increased cellular uptake of potassium.

hyperkalemia

results from increased intake, renal failure, hypoaldosterism, metabolic acidosis, increased red   blood cell lysis, leukemia, chemotherapy.

bicarbonate (HCO3)

Second largest anion fraction of extracellular fluid.

decreased HCO3

associated with metabolic acidosis, diabetic ketoacidosis, salicylate toxicity.

Increased HCO3

associated with metabolic alkalosis, emphysema, severe vomiting.

50% free (ionized), 40% bound to protein, 10% bound to anions

calcium exists in plasma in three forms

parathyroid hormone, vitamin D and calcitonin.

calcium is controlled by

calcium

–Most abundant mineral in the human body

Free form calcium

what form of calcium is biologically active

hypercalcemia

caused by primary hyperparathyroidism, other endocrine disorders and acute adrenal insufficiency, malignancy involving bone and renal failur

hypocalcemia

caused by hypothyroidism, hypoalbuminemia, chronic renal failure, magnesium depletion and vitamin D deficiency.

55% free (ionized), 30% bound to protein, 15% complexed

magnesium exists in plasma in three forms

Magnesium

An intracellular cation second in abundance to K

magnesium

–Important in maintaining the structure of DNA, RNA and ribosomes; synthesis of CHO, CHONS and lipids; neuromuscular transmission’ cofactor, regulates movement of K across myocardium.

kidneys

magnesium is regulated by the

hypermagnesemia

caused by renal failure and excess antacids. Decreased GH, hypothyroidism, hypoaldosterism.

hypomagnesemia

gastrointestinal disorders, renal disease, hyperparathyroidism, drugs, diabetes mellitus with glysuria and alcoholism due to dietary deficiency.

phosphorus

works with calcium to help build bones

phosphorus

–involved in the body's energy production.