Kidney 2 Flashcards
(17 cards)
Where does reabsorption mainly occur?
Occurs mainly (~70% of original filtrate volume) in the Proximal Convoluted Tubule (PCT)
What is the main energy for this transport from the lumen of the PCT back to the plasma?
The sodium/potassium pump
What is secreted at the PCT?
H+ ions, ammonium ions, creatinine and various drugs and toxins
After leaving the PCT what percentage of the filtrate volume originally entering the nephron at the corpuscle has been reabsorbed
60-70%
What percentage of the remaining water and the remaining Na+ and Cl- ions is reabsorbed at the Loop of Henle?
50% of the remaining water
65% of the remaining Na+ and Cl-
What generates an osmotic gradient through the renal medulla?
The unique permeability’s of different segments of the loop these reabsorption activities
What facilitates reabsorption of water and solutes before the distal convoluted tubule (DCT)?
Countercurrent multiplication
What does countercurrent multiplication permit?
Passive reabsorption of water from tubular fluid at the DCT and collecting duct
What percentage of the original filtrate volume reaches the DCT?
15-20%
What do cells of the DCT actively absorb?
Na+, Cl- and Ca2+
What do cells of the DCT secrete?
K+, H+, organic waste, drugs
How is water recaptured?
By facultative absorption
The hormonal regulation for water is?
Anti-diuretic hormone (ADH)
The hormonal regulation for calcium is?
Parathyroid hormone, Calcitriol
The hormonal regulation for sodium is?
Aldosterone
How is Urine volume and osmotic concentration regulated?
By controlling water reabsorption via facultative water reabsorption controlled by ADH
What is the vasa recta is responsible for in the juxtamedullary nephrons?
Returning the solutes and water absorbed in the medulla to the general circulation
