# 04 Renal Physiology II

## Function Measurements

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/GFR,%20RPF,%20urine%20flow%20are/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/fhtMUS1.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/9WTBANR.jpg)

* actual calculation
* GFR: main number for kidney healthiness

![](https://f001.backblazeb2.com/file/wikiFiles/dWJqUs4.jpg)

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/FF%20is/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/9e1HCIb.jpg)

* 40% going across glomerulus, 60% leaving kidney

![](https://f001.backblazeb2.com/file/wikiFiles/9WTBANR.jpg)

* actual calculation
* GFR: main number for kidney healthiness

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/Filtered%20load%20is/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/QezzSNL.jpg)

* how much Na going across glomeruli per min

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/excretion%20rate%20is/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/lPCfVta.jpg)

* urine flow: how much urine kidney making

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/Px,%20Ux,%20V%20are,%20units/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/vW4bzt5.jpg)

* urine flow rate: how much urine pt makes

![](https://f001.backblazeb2.com/file/wikiFiles/dWJqUs4.jpg)

### Clearance

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/Renal%20clearance%20is,%20equation/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/cYZqc1C.jpg)

* urine concentration, urine flow rate , plasma concentration

![](https://f001.backblazeb2.com/file/wikiFiles/kBvKrUx.jpg)

* kidney cleared 5 mole of Na OR
* kidney cleared 1L of blood of Na

## GFR

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/GFR%20determined%202%20ways/README.md)..

* inulin
* creatinine

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/inulin%20determine%20GFR%20how/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/6YkWFB2.jpg)

* all filtered inulin goes out of kidney

![](https://f001.backblazeb2.com/file/wikiFiles/Qo9qLaq.jpg)

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/creatinine%20is,%20determine%20GFR%20error/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/0GAGpGq.jpg)

* naturally clearing, easier to do

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/creatinine%20determine%20GFR%20how,%20equation,%20creatinine%20with%20age/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/a10bgFU.jpg)

* Volume flow cumbersome to determine
* special formula to use

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/Pcr%20and%20GFR%20relationship/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/EveHa4p.jpg)

* amount in urine = amount made in muscles

![](https://f001.backblazeb2.com/file/wikiFiles/8sD9S47.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/PCsLO2m.jpg)

* not a linear, straight line relationship
* plasma Cr concentration, not urine concentration
* use clearance equation to calculate GFR if given urine/plasma concentration and urine flow

## RPF

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/RPF%20is,%20determined%20by%20what%20substance,%20why,%20equation,%20error%20with%20RPF/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/6nS7w1P.jpg)

* small amount goes to CT

![](https://f001.backblazeb2.com/file/wikiFiles/dzaGBqr.jpg)

* everything in goes out, none in the efferent
* calculate amt of blood filtered of PAH (clearance), one can find amt of blood enter kidney

## RBF

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/difference%20between%20plasma%20and%20blood/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/dK3dw6I.jpg)

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/RBF%20calculation%20how/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/BpF8WsY.jpg)

* HCT = bottom red

![](https://f001.backblazeb2.com/file/wikiFiles/UKaIc4Z.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/sDnePEi.jpg)

## Others

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/filtration%20and%20filtration%20load%20are,%20calculated%20how/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/8gkByHZ.jpg)

## Meds

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/NSAIDS%20and%20RBF,%20GFR,%20FF.%20Can%20cause%20what%20acute%20problem)..

![](https://f001.backblazeb2.com/file/wikiFiles/bg9qn5w.jpg)

* FF same: still filtering same percentage of blood
* pt can go into renal failure/heart failure

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/ACE%20I%20and%20GFR,%20RBF,%20FF/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/4cLfHFe.jpg)

* Ang II: constrict efferent, increase GFR, decrease RBF

## Secretion and Absorption

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/filtered%20load%20and%20excretion%20relationship%20with%20urine%20flow%20and%20GFR,%20calculation/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/XA7HCyd.jpg)

* if filtered not = excretion, some must be either secreted or reabsorbed

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/excretion%20formula%20with%20absorption,%20secretion,%20filtration/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/tRARB4B.jpg)

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/filtered%20and%20excreted%20relation%20to%20secretion,%20resorption/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/ju4OFyE.jpg)

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/clearance%20and%20GFR%20relation%20to%20secretion,%20resorption/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/kYBMhwO.jpg)

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/intake%20and%20output.%20Transient%20imbalance%20result)..

![](https://f001.backblazeb2.com/file/wikiFiles/XawoMAu.jpg)

* if put in 10 grams, must excrete 10 grams, otherwise accumulate 

Normal:

![](https://f001.backblazeb2.com/file/wikiFiles/JKnNqkw.jpg)

* 5 in, 5 out, 4 plasma concentration

![](https://f001.backblazeb2.com/file/wikiFiles/xofZC6G.jpg)

* insult: can't excrete, 5 in, 2 out, plasma concentration go up to 6

  ![](https://f001.backblazeb2.com/file/wikiFiles/FL6HrEK.jpg)
* new steady state, 5 in, 5 out, 6 plasma
* new steady state concentration higher than original steady state
* e.g. hyperkalemia, excreting same amount taking in

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/Na,%20K,%20Urea%20in%20renal%20failure%20plasma%20changes/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/kakoqWV.jpg)

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Renal/Na,%20K,%20Urea%20normal%20vs%20lowered%20GFR.%20Concentration,%20filtered%20load,%20excretion,%20fractional%20excretion)..

![](https://f001.backblazeb2.com/file/wikiFiles/zSCRTm3.jpg)

* filtered load: GFR x plasma concentration for urea is same
* fractional excretion: excretion/filtered load, filtered load fallen, amt excreted is same

![](https://f001.backblazeb2.com/file/wikiFiles/rHs0nUq.jpg)

* 5 g filtered, 1 secreted, fractional excretion: 1/5

![](https://f001.backblazeb2.com/file/wikiFiles/uJ0zPs1.jpg)

* renal failure, GFR fallen
* 2 g filtered, 1g excreted, fractional excretion 50%

## Practice Questions

[\_](https://thisispiggy.gitbook.io/my-wiki/01-step-1/renal/04-renal-physiology-ii)

![](https://f001.backblazeb2.com/file/wikiFiles/DUVKKxl.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/WvZODmW.jpg)

* clearance of inulin = GFR

![](https://f001.backblazeb2.com/file/wikiFiles/IhxuMtu.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/IqbG7PA.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/YSsOPZV.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/LSd0zAV.jpg)