Lecture 59 - Regulation of electrolytes by renal tubules Flashcards
what role of the kidneys oversees reabsorption of Na+, K+, Cl-, and Ca2+
controlling electrolyte concentrations
what is the primary determinant of osmolality and volume in ICF/ECF
sodium
the majority of ATP used in active transport contributes to
reabsorption of sodium
T/F: reabsorption of sodium occurs everywhere in the kidneys
FALSE - not the descending loop of henle
the higher the GFR, the ____ electrolytes in ultrafiltrate
more
summarize what happens when Na+ and Cl- are increased in ultrafiltrate
- macula densa senses NaCl
- macula densa release ATP
- constricts afferent arteriole
what are the clinical effects of sodium imbalance
- change in cell size
- cause neurological signs
hyponatremia
- sodium loss or increased free water
- cells swell causing cerebral edema
hypernatremia
- excess sodium or free water loss
- cells shrink and can cause intracranial bleeding
describe how the factor will affect sodium excretion/reabsorption:
increased GFR
increased Na+ in ultrafiltrate
describe how the factor will affect sodium excretion/reabsorption:
aldosterone
sodium reabsorption in DCT and collecting duct
describe how the factor will affect sodium excretion/reabsorption:
angiotensin II
increased reabsorption in proximal tubule
describe how the factor will affect sodium excretion/reabsorption:
ANP (atrial natriuretic peptide)
increases GFR
decreases sodium, reabsorption in DCT and collecting ducts
describe how the factor will affect sodium excretion/reabsorption:
pH
Na+ reabsorbed when H+ excreted
which of the following causes a DECREASE in sodium reabsorption from the ultrafiltrate
a. aldosterone
b. agiotensin II
c. atrial natriuretic peptide
c. atrial natriuretic peptide
plasma concentrations are changed by
- shift K+ transcellularly
- excretion via kidneys
what is a major intracellular cation
potassium
K+ out of cells results in
- hypokalemia
- cell repture
- acidemia
K+ into cells results in
- hyperkalemia
- insulin production
- alkalemia
- B2-agonist
T/F: hyperkalemia is rare with normal renal function
TRUE
how does hypodadrenocorticism (low aldosterone) affect potassium
hyperkalemia and hyponatremia
what causes there to be hyperkalemic periodic paralysis in quarter horses
autosomal dominant mutations in sodium channels
how does aldosterone affect potassium
enhances K+ excretion
hyperkalemia causes
mild = muscle weakness and tremoring
severe = cardiac arrhythmias and arrest
hypokalemia causes
nonspecific signs
malaise and muscle weakness
depression and seizures
arrhythmias
describe calcium ion filtration
reabsorption down chemical and electrical gradient but transporters needed in distal tubule
you are treating a calf with diarrhea. a venous blood gas shows hypokalemia and acidosis. what do you predict will happen to the blood potassium concentration as the acidosis is corrected?
blood potassium will decrease
