Renal Regulation of Ions Flashcards
What does increase in the extracellular potassium level do?
Stimulates increase in aldosterone secretion.
What is the normal intracellular concentration of potassium ions?
140 mEQ/L
Where does reabsorption of the potassium ions occur?
In the proximal tubule and the ascending loop of Henle.
Where does the secretion of Potassium ions occur?
The late tubule and collecting duct.
What stimulated potassium secretion by the principal cells, in the late distal tubule and cortical collecting tubules?
Potassium concentration and aldosterone.
What does small changes in potassium concentration cause?
Large changes in aldosterone secretion by adrenals.
Increased sodium intake decreases aldosterone secretion and, therefore, potassium excretion:
however, increased sodium intake also increases GFR and decreases proximal tubular reabsorption of sodium
What decreases Calcium excretion?
Increased levels PTH, plasma concentration of phosphate, and metabolic acidosis
What stimulates the uptake of potassium by cells?
Insulin and aldosterone
What results from an excess secretion of aldosterone (conn’s syndrome)?
Hypokalemia
What results from a deficiency in aldosterone secretion(Addison’s disease)?
Hyperkalemia
How much calcium is reabsorbed by the kidneys?
Almost all of it.
