Renal 7 & 8 Flashcards
1
Q
Three mechanisms generate/regulate medullary hyperosmolality
A
- countercurrent multiplier
- urea cycle
- countercurrent exchanger
2
Q
countercurrent multiplier
A
establishes initial osmotic gradient
3
Q
urea cycle
A
strengthens osmotic gradient
4
Q
countercurrent exchanger
A
maintains osmotic gradient
5
Q
What happens to the medullary interstitium and vasa recta blood flow during water diuresis?
A
- medullary interstitium osmolality is reduced
- vasa recta blood flow is increased
6
Q
Three major determinants of ECF osmolality
A
- Na+
- Cl-
- HCO-
7
Q
What are causes for ECV and ECF differing?
A
- CHF
- hepatic cirrhosis
- pleural effusion
8
Q
Efferent Effectors regulating ECV
A
- renal sympathetic nerves
- RAA system
- ANP
9
Q
Three factors important in stimulating renin secretion
A
- perfusion pressure
- sympathetic nerve activity
- Delivery of NaCl to macula densa
10
Q
Perfusion Pressure
A
Afferent arteriole acts as a high-pressure baroreceptor.
11
Q
Delivery of NaCl to Macula Densa
A
- tubuloglomerular feedback
- decreased NaCl = enhanced renin secretion
12
Q
Effects of increasing circulating ANP
A
- lower ADH
- water diuresis
- higher GFR
- Na excretion
