(13) - Tubular Reabsorption Flashcards
he didn’t spend much time on this
B (this is the action of a loop diuretic)
A
(Aldosterone and Late Distal TUbule and Collecting Ducts)
- fine regulation of what two things?
- Principal cells present for what?
- What does aldosterone do?
- sodium and potassium
- Na - K exchange
- regulates by insertion of sodium channels
(Where are the sensors?)
- barorecetpors in what two places?
- volume receptors in what?
- juxtaglomerular apparatus measures what?
- carotid sinus and aortic arch (measure blood pressure - stretch)
- atria
- renal perfusion (stimulates renin release)
he says to understand these charts really well
(REcap - Key Points)
- total body sodium content is regulated by what?
- Do kidneys have seperate or combined mechanisms for regulating sodium and water?
- The majority of Na is reabsorbed where?
- the kidneys
- separate
- proximal tubules (with progressively smaller amounts in the loop of Henle, the distal tubules and the collecting ducts)
(Recap - Key Points)
- Reabsorption of Na is what kind of process - driven by what?
(just read it)
kidney regulates Na in long term - not short term - need a way to manage this
(Internal potassium balance)
- normally what percentage in cells? what in ECF?
- Movement of how much into ECF is fatal?
- 98% in cells, 2% in ECF
- 1.5 - 2%
(there are processes that make sure K is moved intracellularly)
(Kidneys: Major Route of K Excretion)
- potassium is freely filtered, but almost all reabsorbed before reaching what?
- Primary Event: Secretion of K into distal tubule - what does this?
- Net distal reabsorption rather than secretion may occur in states of what?
- distal tubule
- principal cells (located in cortical and outer medullary collecting tubule)
- potassium depletion (reabsorption by alpha-intercalated cells)
D
(Recap - K+)
- Short term mamagement of plasma K concentrations depends on what?
- Long-term management controlled by what?
- potassium is filtered, reabsorbed and secreted by what?
- Primary physiologic control of renal handling of K depends on what two factors?
- movement between ECF and ICF
- the kidneys
- the kidneys
- plasma [K] and aldosterone
these dogs don’t make aldosterone - don’t get rid of potassium well - and they lose sodium - so their volume goes down
if potassium is trending up and sodium is trending down keep Addison’s in mind
move on to next slide for explanation
(Phosphorus)
- how filtered?
- Reabsorbed where?
saturatable Tm?
PTH regulates reabsorption by doing what?
- Net Renal handling by what two things?
- unbound freely filtered
- in the proximal tubule
yes
lowering Tm (inhibits cotransporter)
- filtration and reabsorption
(regulation of phosphorus excretion)
- phosphorus excretion largely determined by what?
- Retention of phosphorus in body –> ?
- What does FGF-23 do?
does phosphorus excretion increase or decrease?
- GFR
- release of fibroblast growth factor (FGF-23)
- inhibits renal reabsorption of phosphorus
increase
(REgulation of Phosphorus Excretion)
- Further increases in phosphorus retention and hyperphosphatemia –>…
- increase in levels of what?
does what?
- decrease in levels of what?
this does primarily what?
inhibits production of what?
- parathyroid hormone (PTH) levels
suppress phosphorus reabsorption - thus increasing phosphorus excretion
- calcitrol levels
calcitrol primarily enhances calcium and phosphorus absorption from the gut
inhibits production of PTH (absence promotes increases in PTH)
(Serum Calcium)
1-3. occurs in what three forms?
(ionized calcium)
- biologcially, ergulated, form that is freely filtered
- ionized
- protein-bound (albumin)
- complexed (to organic anions)
(Renal handling of Ca)
- unbound freely filtered
(Reabsorption in PT and TAL)
- passive or paracellular?
- electrochemical driving forces dependent on what?
(Reabsorption in distal tubule)
- site of control by what?
- only segment where reabsorption isn’t what?
- both
- Na reabsorption
- endocrine control (PTH)
- linked to Na
figure this out
