Final- Mg

Question 1

What is the function of magnesium in the body?

Answer 1

Facilitates Na/K atpase activity in cell membranes. Enzyme co
factor for all that use ATP; structural role in bone formation;
important role in PTH synthesis and release (can result in hypocalcemia b/c lack of PTH) role in cell membrane function; nerve conduction, calcium channel activity and phosphorus transport;

Question 2

What are causes of hypomagnesemia?

Answer 2

• LOSS: through the GI tract (malabsorption, diarrhea), kidney (fluid
diuresis, diuretics, renal dz, hypercalcemia will inhibit mg
reabsorption, and skin in horses (sweat).
• Dietary deficiency (in ruminants- grass tetany (high K content of
pasture blocks)
• Mg absorption- milk tetany- calves fed diet of milk low in Mg.

Question 3

What disorders is hypomagnesemia associated w/?

Answer 3

Diabetes mellitus (diuresis), hypercalcemia results in inhibited Mg
reabsorption, hyperaldosteronism (diuresis), third space syndromes
(reduced cation reabsorption due to Cl deficiency)

Question 4

Manifestations of hypomagnesemia

Answer 4

2ndary hypokalemia due to renal wasting of K.
• impaired PTh production and release leading to 2ndary
hypocalcemia.

Question 5

What are clinical signs associated w/ hypomagnesmeia?

Answer 5

Associated w/ 2ndary electrolyte abnormalities (hypokalemia, hypocalcemia) neuromuscular and cardiac abnormalities (hyperexcitability, tremors, fasciculation’s, ataxia, frank tetany, cardiac arrhythmias and possible arrest, coronary artery spasms in humans)

Question 6

What are clinical signs ascoiated w/ hypermagnesemia?

Answer 6

Seen only when renal function compromised (similar to K). Mg
containing laxatives or antacids in concert w/ decreased GFR.
• See paresis, paralysis, heart dysfunction, Gi upset.