Renal - Pt 4 Reabsorption/Secretion/Hormones Flashcards
[] % of reabsorption occurs in the TAL.
25%
There are no [] reabsorption in the TAL due to true tight junctions.
Paracellular
TAL Reabsorption: Apical Membrane
- [] (NKCC) symporters present in the apical membrane. This transporter brings the 3 ions [] the cell.
- [] leak channels allow K+ to leak out of the cell.
- Na+/K+/2 CL- (NKCC) symporters present in the apical membrane. This transporter brings the 3 ions into the cell.
- Potassium leak channels allow K+ to leak out of the cell.
- Resorption in the TAL differs from the PCT in that water [] follow the electrolytes as they are reabsorbed.
- The TAL of the loop of Henle is always [] to water.
- cannot
- impermeable
- [] inhibits the NKCC transport in the TAL
- This causes urine output to dramatically []
- Urine sodium amounts []
- However the body tries to [] Na+ past hthe TAL
- Plasma Potassium Amounts drastically []
- Furosemide inhibits the NKCC transport in the TAL
- This causes urine output to dramatically increase
- Urine sodium amounts increase
- However the body tries to reabsorb Na+ past the TAL
- Plasma Potassium Amounts drastically decrease
TAL Reabsorption: Basolateral Side
- [] and [] leak channels allow the ions to to be reabsorbed through the basolateral membrane
- Na+/K+ pumps move Sodium acorss the basolateral membrane for [].
- Cl- and K+ leak channels allow the ions to to be reabsorbed through the basolateral membrane
- Na+/K+ pumps move Sodium acorss the basolateral membrane for resorption.
T/F
Active transport moves Na+ into the interstitial fluid of th descending limb of the loop of Henle.
False
There is not active transport in the descending limb of the loop of Henle.
- In the descending loop of Henle, [] transport of solutes does not readily occur and there is limited [] to sodium and chloride ions.
- However, [] is freely permeable to move via osmosis to the [] fluid.
- In the descending loop of Henle, active transport of solutes does not readily occur and there is limited permeability to sodium and chloride ions.
- However, water is freely permeable to move via osmosis to the interstitial fluid.
The medullary gradient is formed by the [] cotransporters in the [].
The medullary gradient is formed by the NKCC cotransporters in the TAL.
The osmolarity of fluids in the interstitial space of the cortex is approximately [] mOsm/L, while the osmolarity within the medulla can climb up to values of approx [] mOsm/L.
300 mOsm/L
1200 mOsm/L
- The loop of Henle is associated with the Counter-current [] system
- The vasa recta participate in a diffusion process called the counter current [] system.
- Multiplier
- Exchange
T/F
No reabsorption happens in the DCT.
False
Roughly 5% of solutes still need to be reabsorbed around the DCT…but most solutes are absorbed in the PCT and TAL
- The [] is the main site of hormone reabsorption regulation
- The 2 hormones involved are [] and []
- DCT
- Aldosterone and ADH (anti-diuretic Hormone)
- Aldosterone controls [] reabsorption
- ADH controls [] reabsorption
- Sodium
- water
- The largest percentage of secretion occurs in the [] and [] []
- This is because [] junctions are not true tight junctions in the [], but they are in the DCT. So, when something is [] in the DCT, it stays secreted and cannot leak back into the interstitial fluid.
- The largest percentage of secretion occurs in the DCT and collecting duct
- This is because tight junctions are not true tight junctions in the PCT, but they are in the DCT. So, when something is secreted in the DCT, it stays secreted and cannot leak back into the interstitial fluid.