Pathophysiology of Sodium Handling Flashcards
A “no added salt diet” usually results to ___________.
about 4 grams of salt per day
A “low salt diet” means ___________.
2 grams of salt per day
How much sodium is ____________.
50 grams
Freely permeable solutes (like __________) do not affect the tonicity of water compartments.
urea
Sodium is important (partly) because it determines ECF ________, which consequently determines left ventricular filling volume and mean arterial pressure.
volume
Where are the low-pressure baroreceptors located?
In the venous system:
• Cardiac atria receptors.
• Left ventricular receptors.
• Pulmonary vascular bed receptors.
Where are the high-pressure baroreceptors located?
In the arterial system
What stimulates renin release?
Decreased arterial pressure Decreased sodium delivery ß-adrenergic input Prostaglandins Nitric oxide
What decreases renin secretion?
Increased arterial pressure
Increased sodium delivery
Angiotensin II
ANP
What is glomerular-tubular balance?
A property of the kidney whereby changes in GFR induce proportional changes in proximal tubule resorption
The intrarenal sensors are _________ sensors.
stretch
What percent of filtered sodium is resorbed at the thick ascending loop of Henle?
30%
Aldosterone deficiency can lead to ____________.
salt-wasting nephropathy
What is TGF?
Tubulo-glomerular feedback; the process by which increased sodium levels in the distal arteriole increase afferent-arteriole vasoconstriction
Dopamine and bradykinin work to _________ sodium reabsorption.
decrease
The proximal tubule reabsorbs ______ percent of the sodium.
60%
In the proximal tubule, which side of the luminal cells have Na/K ATPases?
The basolateral side
On the apical side of the proximal tubule, most of the transporters are symporters. Which is an antiporter?
The Na/H antiporter
What transporter does thiazide bind to?
A Na/Cl symporter
You get metabolic __________ from loss of upper GI fluid and metabolic ________ from loss of lower GI fluid.
alkalosis; acidosis
Thiazides increase ________ reabsorption.
calcium
What proteins are defective in Barter’s and Gitelman’s syndromes?
Barter’s: Na/K/2Cl symporter in the TALH
Gitelman: Na/Cl symporter in the DCT
