How Urine becomes concentrated Flashcards
What two factors develop the medullary gradient?
Ions to the interstitium at thick LOH
Urea from medullary collecting ducts
Where does ADH act?
Collecting duct, inserts aquaporins allowing H2O to move out of the collecting ducts
What two factors determine the ability to concentrate the urine?
Medullary osmotic gradient
Permeability of collecting tubule
Wy does the renal medullary interstitium hyper osmotic gradient not wash away?
Blood flow to the renal medulla is low
What structures supply blood to the renal medulla?
peritubular capillaries called vasa recta
What is the purpose of creating a hyperosmolar medulla?
Energy efficient way of reabsorbing water by osmosis
How is urea created?
Metabolic waste product of protein metabolism
Where do K sparing diuretic work?
Principal cells, blocks aldosterone which normally facilitates the Na/K pump
Where do loop diuretics work?
Thick ascending loop by inhibiting Na K Cl symporter causing loss of Mg and Ca as well
How do Mg and Ca typically move into the ISF?
Paracellularly as a result of positive charge potential created with the loss of K ions
Where do thiazide diuretics work?
Early distal and late proximal tubule, by inhibiting Na/Cl co transporter resulting in reduced reabsorption of Na and Cl
Where do carbonic anhydrase inhibitors work?
Proximal tubule, by preventing dissociation of CO2 to H= and HCO3 resulting in loss Na HCO3 and H2O
What metabolic disturbance can occur with a CA inhibitor?
Hyperchloremic metabolic acidosis
