Renal Discussions Flashcards
1
Q
Body osmolarity based on plasma [Na+]
A
Body osmolarity is close to twice plasma [Na+]
2
Q
Exchangeable Na+
A
Portion of total body Na+ readily available; most is in ECF
3
Q
Where is most body K+ located?
A
98% inside cells
4
Q
Effective Circulating Volume
A
Degree of filling in arterial system reflecting extent of tissue perfusion; can differ from ECF volume
5
Q
Regulation of sodium transporters
A
PT: NE, A-II -> NHE3 activity
TAL: ADH -> NKCC activity
DT: Aldo -> NCCs
cCD: Aldo -> ENaCs
mCD: ADH -> AQPs
6
Q
How does increased tubular flow affect K+ levels?
A
Increased tubular flow increases K+ secretion by:
1. Upreg of BK due to cilia deflection and Ca++ influx
2. Maintaining high K+ gradient for secretion
7
Q
How does Na+ delivery affect K+?
A
- Increased Na+ reabsorption activates basal Na/K ATPase, improving the K+ gradient for secretion
- Increased Na+ reabsorption depolarizes the cell and provides more electrical gradient driving K+ secretion
