Control of Sodium and Water Excretion

Question 0

Hemorrhage effects on GFR

Answer 0

Decreased plasma protein concentration normally leads to increased GFR

HOWEVER

The decreased arterial pressure increases sympathetic action causing decreased glomerular capillary pressure and decreased GFR

Question 1

Regulation of Glomerular-Capillary Pressure

Answer 1

Extrarenal baroreceptors in the carotid sinus and decrease GFR when detecting increased capillary colloid pressure; stimulates the secretion of renin

Question 2

Aldosterone Function

Answer 2

Binds to intracellular receptors leading to an increase in the synthesis of luminal-membrane Na+ channels and basolateral Na+/K+ pummps

*Produced by the zona glomerulosa of the adrenals

Question 3

Control of aldosterone secretion

Answer 3

Stimulates: ACTH, Increased [K+], Angiotensin II

Inhibits: ANP

Question 4

Control of renin secretion

Answer 4

Intrarenal baroreceptors, macula densa, and renal sympathetic nerves

Question 5

RIHP effects on Na+ absorption

Answer 5

Indirectly related

*Inputs that decrease GFR also increase RIHP

Question 6

Effects of Renal Nerve Stimulation

Answer 6

• Stimulates renin secretion on B1-receptors of granular cells
• Stimulates Na+ reabsorption via direct action on tubular cells
• Stimulates afferent/efferent arteriole constriction

Question 7

Pressure natiuresis

Answer 7

Rapid increase in Na+ excretion when the renal arterial pressure shows a slight increase

Question 8

ANP

Answer 8

Direct effects: Acts on CDs to decrease Na+ reabsorption (inhibition of Na+ channels)

Indirect effects: Acts on granular cells to decrease renin secretion
Acts on adrenals to decrease aldosterone secretion
Causes afferent arteriole dilation/efferent constriction
Dilation of mesangial cells => Increased Kf

Question 9

Glomerulotubular Balance

Answer 9

Changes in GFR leading to directly proportional changes in absolute Na+ reabsorption IN THE PROXIMAL TUBULES