Renal Transport Flashcards
Why is Na/K ATPase so important?
Creates a gradient by taking Na out of the cell so more in allowed to go inside
Mechanism of NHE3
Na+ IN to cell
H+ OUT
(Responsible for 80% of sodium reabsorption)
Where is AQE 1 found?
Proximal Tubule
Where is AQE 2 found?
Collecting Duct
What transporters are in the Proximal Convoluted Tubule? (5)
Na/K NHE3 SGLT 2 and SGLT1 AQE 1 KCC Symporter
What is reabsorbed in the Proximal Convoluted Tubule?
100% Glucose 100% Acids 50% Urea 70% Sodium, Potassium Calcium, Water 30% Magnesium
What is reabsorbed in the Proximal Straight Tubule?
15% phosphate
What is reabsorbed in the descending limb of LoH?
WATER!
What is reabsorbed in the Thick ascending limb of LoH?
25% Sodium, Calcium
20% Potassium
60% Magnesium
Where is the tubular fluid most concentrated?
Bottom of loop of henle
What transporters are in the Thick ascending LoH?
Na-K-Cl2
Na/K ATPase
Mechanism of Na-K-Cl2?
1 Na, 1 K, 2 Cl- all move into the cell, creates a positive voltage charge so it also drives the movement of positive ions into the cell
How does Carbonic anhydrase work?
Prevents tubule from becoming too acidic by recycling H+ into bicarb and shuttling it into the cell.
Where is the tubular fluid isoosmotic?
PCT
Where is the tubular fluid hyperosmotic?
Descending LoH
Where is the tubular fluid hypoosmotic?
Ascending LoH
Where do Loop diuretics act?
Thick ascending LoH
What do Loop Diuretics do?
Inhibit Na reabsorption by competing for NaCl site on NaKCl2 receptor
Where do Thiazide diuretics act?
Distal Convoluted Tubule
How do Thiazide diruects work?
Block Na-Cl Symporter: inhibit Na/Cl reabsorption and allow more reabsorption of Ca
What transporters are in the Distal Convoluted tubule?
NCC
Na- Ca exchange
What is reabsorbed in DCT?
5% Sodium, Magnesium
8% Calcium
H2o and urea
Where does Spironolactone act?
Collecting Duct
What is reabsorbed in the collecting duct?
3% sodium
water and urea
What is reabsorbed in the bladder?
Potassium (1-100%)
Magnesium- 5%
Phosphate- 15%
Characteristics of SGLT1
High affinity, Low capacity
10% of distal PCT Glucose reabsorption
SGLT2
First 2/3 of PCT
Low affinity, high capacity
**Problematic in Diabetes)
How does Spironolactone work?
Inhibit Na/K ATPase
- Promote K+ retention and loss of Na+ and water
Where does AGT II work? (4)
PCT
TAL
DCT
CD
Where does Aldosterone work? (3)
TAL
DCT
CD
Where do ANP, BNP, and Urodilatin work? (3)
CD
Where do Uroguanylin and guanylin work?
PT
CD
Where do sympathetic nerves work?
PT
TAL
DCT
CD
Where does Dopamine work?
PCT
Where does AVP work?
DT
CD
What hormones increase water and sodium reabsorption? (3)
AGT2, Aldosterone, Sympathetic Nerves
Will INCREASE blood volume
What hormones DECREASE NaCl and water reabsorption? (6)
ANP, BNP, Urodilation, UroG and Guan, Dopamine
What hormone increases water reabsorption?
AVP
What stimulates more Aldosterone?
Increase in K+ plasma concentration
Aldosterone will increase K+ secretion to retain more Na+ and water
