WGU D236 pathophysiology: Objective A
n n n n
ssessment Questions and Verified Answers
n n n n
| Latest 2023/2024 GRADED A+
n n n n n
WhatnisnStarling'snLawnofnCapillarynforces?
Howndoesnthisnexplainnwhynannutritionallyndeficientnchildnwouldnhavenedema?
-
n ☑️☑️Starling'sn Lawn describesn hown fluidsn moven acrossn then capillaryn membrane.n Theren arentwonmajornopposin
gnforcesnthatnactntonbalanceneachnother,nhydrostaticnpressuren(pushingnwaternoutnofnthencapillaries)nan
dnosmoticnpressuren(includingnonconticnpressure,nwhichnpushesnfluidnintonthencapillaries).
Bothnelectrolytesnandnproteinsn(onconticnpressure)ninnthenbloodnaffectnosmoticnpressure,nhig
hnelectrolytenandnproteinnconcentrationsninnthenbloodnwouldncausenwaterntonleaventhencellsna
ndninterstitialnspacenandnenternthenbloodnstreamntondilutenthenhighnconcentrations.
On,nthenothernhand,nlownelectrolytenandnproteinnconcentrationsn(asnseenninnannutritionallyndeficientnch
ild)nwouldncausenwaterntonleaventhencapillariesnandnenternthencellsnandninterstitialnfluidnwhichncannleadnt
onedema.
HowndoesnthenRAASn(Renin-Angiotensin-
AldosteronenSystem)nresultninnincreasednbloodnvolumenandnincreasednbloodnpressure?
,WGUnD236npathophysiologynOAnExamnStudynGuiden2023nQuestionsnandnAnswers
-
☑️☑️Andropninn bloodn pressurenisnsensednbyn then kidneysn bynlown perfusion,n whichninnturnnbeginsn tonsecretenre
n
nin.
Reninnthenntriggersnthenliverntonproducenangiotensinogen,nwhichnisnconvertedntonAngiotensinnIninnthenlun
gsnandnthennangiotensinnIInbynthenenzyme
Angiotensin-
convertingnenzymen(ACE).nAngiotensinnIInstimulatesnperipheralnarterialnvasoconstrictionnwhichnraisesnBP.
AngiotensinnIInisnalsonstimulatingnthenadrenalnglandntonreleasenaldosterone,nwhichnactsntonincreasensodi
umnandnwaternreabsorptionnincreasingnbloodnvolume,nwhilenalsonincreasednpotassiumnsecretionninnurine
.
Howncannhyperkalemianleadntoncardiacnarrest?
-
n ☑️☑️Normaln levelsn ofn potassiumn aren betweenn 3.5n andn 5.2n mEq/dL.n Hyperkalemian refersn topotassiumnlevelsnh
ighernthatn5.2nmEq/dL.
Anmajornfunctionnofnpotassiumnisntonconductnnervenimpulsesninnmuscles.nToonlownandnmusclenweaknessn
occursnandntoonmuchncanncausenmusclenspasms.
,WGUnD236npathophysiologynOAnExamnStudynGuiden2023nQuestionsnandnAnswers
Thisnisnespeciallyndangerousninnthenheartnmusclenandnannirregularnheartbeatncanncausenanheartnattack
ThenbodynusesnthenProteinnBufferingnSystem,nPhosphatenBufferingnSystem,nandnCarbonicnAcid-
n BicarbonatenSystemntonregulatenandnmaintainnhomeostaticnpH,nwhatnisnthenconsequencenofnanpHnimbala
nce
- ☑️☑️ProteinsncontainnmanynacidicnandnbasicngroupnthatncannbenaffectednbynpHnchanges.nAnynincreasenorndecre
aseninnbloodnpHncannalternthenstructurenofnthenproteinn(denature),ntherebynaffectingnitsnfunctionnasnwell
Describenthenlaboratorynfindingsnassociatednwithnmetabolicnacidosis,nmetabolicnalkalosis,nrespiratorynacido
sisnandnrespiratorynalkalosis.n(ienrelativenpHnandnCO2nlevels).
- ☑️☑️Normaln ABGsn(Arterialn Bloodn Gases)n Bloodn pH:n 7.35-7.45n PCO2:n 35-45n mmn Hgn PO2:n 90-
100n mmnHgnHCO3-:n22-26nmEq/LnSaO2:n95-100%
RespiratorynacidosisnandnalkalosisnarenmarkednbynchangesninnPCO2.nHighern=nacidosisnandnlowern=nalkalo
sis
MetabolicnacidosisnandnalkalosisnarencausednbynsomethingnothernthannabnormalnCO2nlevels.nThisncouldnincl
udentoxicity,ndiabetes,nrenalnfailurenornexcessivenGInlosses.
, WGUnD236npathophysiologynOAnExamnStudynGuiden2023nQuestionsnandnAnswers
Herenarenthenrulesntonfollowntondeterminenifnisnrespiratorynornmetabolicninnnature.n-
IfnpHnandnPCO2narenmovingninnoppositendirections,nthennitnisnthenpCO2nlevelsnthatnarencausingnthenimbal
ancenandnitnisnrespiratoryninnnature.
-
IfnPCO2nisnnormalnornisnmovingninnthensamendirectionnasnthenpH,nthennthenimbalancenisnmetabolicninnnatu
re.
Thenanionngapnisnthendifferencenbetweennmeasuredncationsn(Na+nandnK+)nandnmeasurednanionsn(Cl-
andnHCO3-),nthisncalculationncannbenusefulninndeterminingnthencausenofnmetabolicnacidosis.
n
Whynwouldnannincreasednanionngapnbenobservedninndiabeticnketoacidosisnornlacticnacidosis?
- ☑️☑️Then anionn gapn isn then calculationn ofn unmeasuredn anionsn inn then blood.
Lacticnacidnandnketonesnbothnleadntonthenproductionnofnunmeasurednanions,nwhichnremovenHCO3-
(anmeasurednanion)nduentonbufferingnofnthenexcessnH+nandnthereforenleadsntonannincreaseninnthenAG.
n
Whynisnitnimportantntonmaintainnanhomeostaticnbalancenofnglucoseninnthenbloodn(iendescribenthenpathogene
sisnofndiabetes)?
- ☑️☑️Insulinnisnthenhormonenresponsiblen forn initiatingn thenuptaken ofnglucosenbyn thencells.n Cellsnusengluc
osentonproducenenergyn(ATP).
n n n n
ssessment Questions and Verified Answers
n n n n
| Latest 2023/2024 GRADED A+
n n n n n
WhatnisnStarling'snLawnofnCapillarynforces?
Howndoesnthisnexplainnwhynannutritionallyndeficientnchildnwouldnhavenedema?
-
n ☑️☑️Starling'sn Lawn describesn hown fluidsn moven acrossn then capillaryn membrane.n Theren arentwonmajornopposin
gnforcesnthatnactntonbalanceneachnother,nhydrostaticnpressuren(pushingnwaternoutnofnthencapillaries)nan
dnosmoticnpressuren(includingnonconticnpressure,nwhichnpushesnfluidnintonthencapillaries).
Bothnelectrolytesnandnproteinsn(onconticnpressure)ninnthenbloodnaffectnosmoticnpressure,nhig
hnelectrolytenandnproteinnconcentrationsninnthenbloodnwouldncausenwaterntonleaventhencellsna
ndninterstitialnspacenandnenternthenbloodnstreamntondilutenthenhighnconcentrations.
On,nthenothernhand,nlownelectrolytenandnproteinnconcentrationsn(asnseenninnannutritionallyndeficientnch
ild)nwouldncausenwaterntonleaventhencapillariesnandnenternthencellsnandninterstitialnfluidnwhichncannleadnt
onedema.
HowndoesnthenRAASn(Renin-Angiotensin-
AldosteronenSystem)nresultninnincreasednbloodnvolumenandnincreasednbloodnpressure?
,WGUnD236npathophysiologynOAnExamnStudynGuiden2023nQuestionsnandnAnswers
-
☑️☑️Andropninn bloodn pressurenisnsensednbyn then kidneysn bynlown perfusion,n whichninnturnnbeginsn tonsecretenre
n
nin.
Reninnthenntriggersnthenliverntonproducenangiotensinogen,nwhichnisnconvertedntonAngiotensinnIninnthenlun
gsnandnthennangiotensinnIInbynthenenzyme
Angiotensin-
convertingnenzymen(ACE).nAngiotensinnIInstimulatesnperipheralnarterialnvasoconstrictionnwhichnraisesnBP.
AngiotensinnIInisnalsonstimulatingnthenadrenalnglandntonreleasenaldosterone,nwhichnactsntonincreasensodi
umnandnwaternreabsorptionnincreasingnbloodnvolume,nwhilenalsonincreasednpotassiumnsecretionninnurine
.
Howncannhyperkalemianleadntoncardiacnarrest?
-
n ☑️☑️Normaln levelsn ofn potassiumn aren betweenn 3.5n andn 5.2n mEq/dL.n Hyperkalemian refersn topotassiumnlevelsnh
ighernthatn5.2nmEq/dL.
Anmajornfunctionnofnpotassiumnisntonconductnnervenimpulsesninnmuscles.nToonlownandnmusclenweaknessn
occursnandntoonmuchncanncausenmusclenspasms.
,WGUnD236npathophysiologynOAnExamnStudynGuiden2023nQuestionsnandnAnswers
Thisnisnespeciallyndangerousninnthenheartnmusclenandnannirregularnheartbeatncanncausenanheartnattack
ThenbodynusesnthenProteinnBufferingnSystem,nPhosphatenBufferingnSystem,nandnCarbonicnAcid-
n BicarbonatenSystemntonregulatenandnmaintainnhomeostaticnpH,nwhatnisnthenconsequencenofnanpHnimbala
nce
- ☑️☑️ProteinsncontainnmanynacidicnandnbasicngroupnthatncannbenaffectednbynpHnchanges.nAnynincreasenorndecre
aseninnbloodnpHncannalternthenstructurenofnthenproteinn(denature),ntherebynaffectingnitsnfunctionnasnwell
Describenthenlaboratorynfindingsnassociatednwithnmetabolicnacidosis,nmetabolicnalkalosis,nrespiratorynacido
sisnandnrespiratorynalkalosis.n(ienrelativenpHnandnCO2nlevels).
- ☑️☑️Normaln ABGsn(Arterialn Bloodn Gases)n Bloodn pH:n 7.35-7.45n PCO2:n 35-45n mmn Hgn PO2:n 90-
100n mmnHgnHCO3-:n22-26nmEq/LnSaO2:n95-100%
RespiratorynacidosisnandnalkalosisnarenmarkednbynchangesninnPCO2.nHighern=nacidosisnandnlowern=nalkalo
sis
MetabolicnacidosisnandnalkalosisnarencausednbynsomethingnothernthannabnormalnCO2nlevels.nThisncouldnincl
udentoxicity,ndiabetes,nrenalnfailurenornexcessivenGInlosses.
, WGUnD236npathophysiologynOAnExamnStudynGuiden2023nQuestionsnandnAnswers
Herenarenthenrulesntonfollowntondeterminenifnisnrespiratorynornmetabolicninnnature.n-
IfnpHnandnPCO2narenmovingninnoppositendirections,nthennitnisnthenpCO2nlevelsnthatnarencausingnthenimbal
ancenandnitnisnrespiratoryninnnature.
-
IfnPCO2nisnnormalnornisnmovingninnthensamendirectionnasnthenpH,nthennthenimbalancenisnmetabolicninnnatu
re.
Thenanionngapnisnthendifferencenbetweennmeasuredncationsn(Na+nandnK+)nandnmeasurednanionsn(Cl-
andnHCO3-),nthisncalculationncannbenusefulninndeterminingnthencausenofnmetabolicnacidosis.
n
Whynwouldnannincreasednanionngapnbenobservedninndiabeticnketoacidosisnornlacticnacidosis?
- ☑️☑️Then anionn gapn isn then calculationn ofn unmeasuredn anionsn inn then blood.
Lacticnacidnandnketonesnbothnleadntonthenproductionnofnunmeasurednanions,nwhichnremovenHCO3-
(anmeasurednanion)nduentonbufferingnofnthenexcessnH+nandnthereforenleadsntonannincreaseninnthenAG.
n
Whynisnitnimportantntonmaintainnanhomeostaticnbalancenofnglucoseninnthenbloodn(iendescribenthenpathogene
sisnofndiabetes)?
- ☑️☑️Insulinnisnthenhormonenresponsiblen forn initiatingn thenuptaken ofnglucosenbyn thencells.n Cellsnusengluc
osentonproducenenergyn(ATP).
