Lecture 6 Final Flashcards
How much PAH can the kidneys remove
90%
Does Angiotensin II only work on the efferent arteriole?
No, it works on both but mainly on the efferent arteriole.
What does the Macula Densa release to make the afferent arteriole dilate?
Nitrous Oxide
Can the Macula Densa also relax the efferent arteriole with the use of NO?
Yes, it can work on both arteriole as well but mainly work on the afferent arteriole.
What does the angiotensin 2 type 1 receptors do?
Located in proximal tubule, when bound, it speeds up the Na/K pump located next to it as well as the secondary transporters (NHE) within that area.
What transporters also get sped up after the Na/K pump is sped up in the PCT?
Na to interstitium; K influx (cell)
NHE (secondary)
1 Na influx, 1 H+ to the lumen
Na/bicarb secondary active
1 Na;1 bicarb to the interstitium
T/F: When H+ is transported into the lumen, bicarb is transported into the interstitium as well.
True
Where else does reabsorption occur?
“Tight junctions”
Paracellular pathways (in between cells) mainly water but CL- is also dragged here.
Trancellular pathway (through a channel in the cell wall)
Which ion mainly is involved within our primary and secondary transporters in the renal system?
Na+
T/F: Normally where Na goes, Cl- follows through the paracellular pathways.
True
Aquaporins are normally called…
Transcellular route/pathway
What is bulk flow? where does this occur?
- Tons and tons of reabsorption/filtration
- In the peritubular capillaries and glomerular capillaries
Which transport system does water go through in the renal system?
There isn’t one, it only travels through tight junctions or through osmosis.
What is the main solute does water follow in the renal system?
Urea
What drives transcellular pathways?
Some primary active transporter within the cell
On the lumen side of the proximal tubular cells, there’s a rush/rough border made up of?
Lining of proximal tubular cells (20 fold). Lots of surface area for multiple transporters.
Why is the cell wall of the PCT on the lumen side not flat?
It would be too crowded with the amount of transporters it uses. Having the rush/rough border allows for more transporters to be planted and used for reabsorption.
What is the typical membrane potential in the kidney?
-70 mV
The ions that are left inside the lumen creates a charge of?
-3mV
Does Na ever get concentrated in the PCT?
No, water follows it to keep it controlled. But Cl- does.
T/F:
Large negatively charged compounds like proteins are filtered through the capillaries?
False, but sometimes some albumin gets filtered (ex. 0.001 = 1.8g/day)
If 1.8g of protein are filtered/day, and 1.7g are reabsorbed, how much is excreted?
100mg of protein in urine. (Should not make it look cloudy)
What’s the purpose of the proximal tubular cell?
It will pull the protein from the peritubular capillaries and pull it apart to turn it into amino acids. (aka endocytosis; pinocytosis)
What do you call a string of at least 10 amino acids?
Peptide