Tubular Transport of NaCl and Water Flashcards
What does the macula densa do in response to increased NaCl?
it signals the afferent arteriole to contract in order to maintain GFR
What is the proportion of NaCl and water that is ALWAYS absorbed?
65%
Nearly all of the obligatory recapture of water and salt occurs in the ______.
“proximal segments” (i.e. proximal tubule and loop of Henle)
What is another name for vasopressin?
ADH
What is another name for ADH?
vasopressin
What does aldosterone do in the DCT and collecting duct?
- increases the number of apical sodium channels and basolateral sodium pumps
- increases ATP synthesis
What pump is found in the ascending loop of Henle?
Na/K/2Cl cotransporter
The filtrate is isotonic in the PCT. What is it like in the Loop of Henle?
hypotonic
Reabsorption of _____, _____, and _____ are coupled to the active reabsorption of sodium.
- chloride
- water
- other solutes
Most of the filtered load of water and salt is _____, with only a small fraction under homeostatic control.
obligatorily reabsorbed
______ refers to the ability of the obligatory reabsorption mechanisms in the proximal tubule to compensate for changes in filtered load.
Glomerulotubular balance
How fast does aldosterone work? Why?
slower than ADH- takes about 1 hour (bc of gene transcription)
Most diuretics tend to increase the urinary excretion rate of ____, _____, and _____ indirectly due to their effect on water flow.
sodium, potassium, and chloride
The main driving force for flow of reabsorbed fluid back into the capillaries is ______.
the osmotic pressure of the capillary plasma
Reabsorption of chloride, water, and other solutes are coupled to the active reabsorption of ______.
sodium
