Control Of Body Fluid Volume Flashcards
1
Q
What cells sense the composition of the tubular fluid?
How do they bring in Na+?
A
Macula Densa cells
Na-2Cl-K Symport on Apical Membrane
2
Q
Renin is made and stored in the JGA of the kidneys.
What are 3 things that signal its release?
A
- Increased sympathetic innervation of Granular cells
- Fall in tension of Afferent Arteriole walls
- Decreased Na+ to Macula Densa (MD cells secrete prostaglandins which act on Granular cells causing renin release)
3
Q
What are 2 effects of Angiotensin II in the kidney?
A
- Arteriole vasoconstriction (Efferent more than Afferent)
- Stimulates Aldosterone release from Zona Glomerulosa (This causes ADH release, Thirst and increases PCT Na reabsorption)
4
Q
A decrease in circulating volume stimulates prostaglandin synthesis.
What are 3 places this occurs in the kidney?
How do they affect Na Reabsorption?
A
- Cortex
- Medullary Interstitial Cells
- Collecting Duct Interstitial Cells
- Cause renin release in granular cells
- Act as vasodilators by preventing excess vasoconstriction of arterioles
5
Q
ANP is made by cardiac atrial cells in response to increased ECF volume
How does it affect;
- Na-K ATPase
- Na channels in CD and PCT
- Aldosterone secretion
- ADH Release
- Renin Release
- Afferent arterioles
A
- Inhibits Na-K ATPase
- Closes Na channels in CD and PCT
- Inhibit aldosterone secretion
- Inhibit ADH release
- Decrease renin release
- Vasodilate Afferent arterioles to increase GFR
6
Q
What are Pressure Diuresis and Pressure Natriuresis?
How are they correlated?
A
Increased water excretion
Increased sodium excretion
Always occur together (Cannot be independently controlled)
