Mangiarua - Control Of Na And H2O Excretion Flashcards
Low total-body sodium causes __________ cardiovascular pressures, which via baroreceptors, initiate reflexes and decrease GFR are increase Na reabsorbtion, which overall decreases sodium excretion, retaining sodium
Low
How can you control GFR?
Phsyiological regulation of glomerular-capillary pressure
Physiological changes in plasma protein concentration
Renin secretion is stimulated by ____ and _____
Intrarenal baroreceptors
Renal sympathetic nerves
The single most important controller of sodium reabsorption
Aldosterone
Things that inhibit aldosterone secretion ?
Atrial natriuretic peptide
Things that stimulate aldosterone secretion:
ACTH
Increased plasma potassium concentration
Angiotensin II
Aldosterone is produced by the _______ in the adrenal cortex
Zona glomerulosa
Aldosterone stimulates sodium reabsorption mainly in the ________ in the cortical collecting duct
Principal cells
In complete absence of aldosterone, a person will excrete about ___% of Filtered sodium. With maximal plasma aldosterone, virtually no sodium is excreted
2
Mechanism of action for aldosterone
Binds to intracellular receptors, increase mRNA synthesis, increase translation of protein, increase activity or number of luminal-membrane Na channels and basolateral-membrane Na-K ATPase pumps
Renal sympathetic nerves stimulate _____ secretion via a direct action on beta-1 receptors of granular cells
Renin
Effects of renal sympathetic nerve stimulation
Renin secretion via action on beta-1 receptors of granular cells
Sodium reabsorption via direct action on tubular cells (at proximal tubule)
Afferent and efferent arteriole constriction (leads to Na reabsorption)
The major regulated determinant of water excretion is
The rate of water reabsorption
