Secretion/K+ Regulation Flashcards
secretion
movement of a solute from blood into lumen of nephron
why do organic acids/bases competitively inhibit each other
they share a common carrier protein, experience competitive inhibition
how does low urine pH affect secretion
decreases
how does low urine pH affect excretion
decreases
how does low urine pH affect plasma concentration of organic acids
increases
are membranes more permeable to associated or disassocaited forms
associated
how do you calculated secretion
secreted = excreted - Filtered
why can you use PAH to measure ERPF?
PAH is filtered and secreted so it gets removed from the renal circulation - basically it’s a measure of volume of plasma that entered the kidney per unit time
what is ERPF
effective renal plasma flow
What is the equation for ERPF using PAH
Clearance = urine conc of PAH x volume/ plasma conc of PAH
calculate filtration fraction
FF = GFR/ERPF
why do the nephron segments upstream of distal tubule not contribute to the regulation of potassium balance
regardless of the conc of potassium in plasma the same percentage of filtered potassium is reabsorbed before you get to the distal tubule
how does hyperkalemia affect aldosterone secretion
stimulates
how does increased plasma potassium affect he Na+/K+APTase pump on the basolateral membrane of teh principle cells in the late distal tubule
the pump works. hypokalemia inhibits the pump
how does aldosterone affect the Na+?K+ATPase pump?
stimulates
