Examl 4:l BIOl 202/l BIO202l (Latestl 2025/l
2026l Update)l Humanl Anatomyl andl Physiologyl IIl Guide|l Questionsl &l Answers|l Gradel A|l 100%l Correctl (Verifiedl Solutions)-l GCU
Q:l Generally,l whichl regionsl ofl thel renall tubulel doesl reabsorptionl andl secretionl takel placel in?
Answer:
Proximall Convolutedl Tubulel (PCT)-reabsorption Distall Convolutedl Tubulel (DCT)-secretion
Q:l Whichl regionsl ofl thel renall tubulel arel inl thel cortexl ofl thel kidneyl andl whichl arel inl thel medullal ofl thel kidney?
Answer:
PCTl andl DCTl arel locatedl inl thel cortex -Loopl ofl Henlel extendsl partiallyl intol medulla -collectingl ductl startsl inl thel cortexl andl endsl inl thel medulla
Q:l Describel thel "drainagel system"l ofl thel nephrons.
Answer:
beginsl inl cortex,l descendsl intol medulla, carriesl fluidl tol papillaryl ductl thatl drainsl intol al minorl calyx
Q:l Comparel andl contrastl corticall andl juxtamedullaryl nephrons.
Answer:
*Corticall Nephrons*l 85%l ofl alll nephrons 1 / 4
Locatedl mostlyl withinl superficiall cortexl ofl kidney Nephronl loopl (Loopl ofl Henle)l isl relativelyl short Efferentl arteriolel deliversl bloodl tol al networkl ofl peritubularl capillaries *Juxtamedullaryl Nephronsl (juxta-l meansl nextl to...)* 15%l ofl nephrons Nephronl loopsl extendl deepl intol medulla Peritubularl capillariesl connectl tol vasal rectal (longl straightl capillariesl runningl parallell tol thel loopl ofl Henle)
Q:l Drawl outl thel microscopicl anatomyl ofl thel glomerulusl makingl surel tol includel thel
relationshipsl ofl thel followingl structures:
a.l Podocytes b.l Pedicles c.l Filtrationl Slits d.l Fenstratedl capillairesl andl theirl associatedl pores e.l Laminal densal (basementl membrane)
Answer:
a.l podocytes:l composesl viscerall epithelium,l wrapl aroundl specializedl densel layer,l ofl glomerularl capillaries,l mostl selective b.l pedicles:l "feet"l wrapl aroundl specializedl densel layerl ofl glomerularl capillaries c.l filtrationl slits:l narrowl gapsl betweenl adjacentl pedicels,l materialsl passingl outl ofl bloodl atl glomerulus,l keepsl proteinsl outl mostl selctive d.l fenstatedl capillariesl andl theirl associatedl pores:l inl glomerularl capillaryl beds,l endotheliuml containsl largel diameterl pores e.l laminal densa:l basementl membrane,l morel selective,l onlyl allowsl diffusionl ofl smalll plasmal proteins,l nutrientsl orl ions
Q:l Definel osmolarityl andl thenl describel osmolarityl inl yourl ownl wordsl sol thatl itl makesl sense.
Answer:
Whenl lessl thanl 300l overl hydratedl Higherl thanl 300l dehydrated Totall numberl ofl solutel particlesl perl liter
Q:l Explainl osmoticl pressure.
Answer: 2 / 4
Proteinl andl otherl solutesl drawl inl fluidl inl specificallyl water,l it'sl thel "pull"
Q:l Comparel andl contrastl hydrostaticl pressurel andl colloidl osmoticl pressure.
Answer:
Glomerularl filtrationl isl governedl byl thel balancel between.....Hydrostaticl pressurel (fluidl pressure) Colloidl osmoticl pressurel (ofl materialsl inl solution) .....Onl eitherl sidel ofl capillaryl walls Filtrationl hasl tol stayl thel samel 10mmHg
Q:l Drawl outl al simplel diagraml thatl illustratesl glomerularl filtrationl including: a.l GHP b.l BCOP c.l CsHP d.l Capillaryl colloidl osmoticl pressure
Answer:
A.l Glomerularl hydrostaticl pressure:l thel pressurel inl thel capillariesl generatedl froml thel heart,l goesl froml bloodl tol urine B.l Bloodl colloidl osmoticl pressure:opposesl filtration,l drawsl waterl outl ofl filtratel intol plasma,l froml glomerulusl intol capillariesl C.l Capsularl hydrostaticl pressure:l goesl froml urinel tol blood,l opposingl forcel butl GHPl isl bigger D.l Capillaryl colloidl osmoticl pressure:l usuallyl zerol becausel fewl ifl anyl plasmal proteinsl enterl thel capsularl space -alll withinl bowman'sl space
Q:l Explainl whatl exactlyl GRFl is.l Notl justl whatl itl standsl for,l butl whatl itl actuallyl measures!
Answer:
Glomerularl filtrationl rate Isl thel amountl ofl filtratel kidneysl producel eachl minute Averagesl 125l ml/min
Aboutl 10%l ofl fluidl deliveredl tol kidneys:
leavesl bloodstreaml entersl capsularl spaces
- / 4
Glomerulil generatel aboutl 180l litersl ofl filtratel perl day:l
99%l isl reabsorbedl inl renall tubules
Q:l Generally,l whatl threel factorsl affectl filtrationl pressure?
Answer:
Autoregulationl (locall level)l whatl thel kidneyl itselfl canl dol itl help Hormonall regulationl (initiatedl byl kidneys) Autonomicl regulationl (byl sympatheticl divisionl ofl ANS)
Q:l Describel thel physiologyl ofl autoregulationl ofl GFR.l Makel surel tol includel thel importancel ofl thel JGA.l Thisl isl notl somethingl thatl youl canl justl memorize.l Instead,l askl yourselfl howl changesl inl bloodl pressurel throughl thel regionl ofl thel renall corpusclel willl affectl thel diametersl andl flowl throughl thel afferentl arterioles,l efferentl arteriolesl andl glomerularl capillaries.
Answer:
Maintainsl GFRl despitel changesl inl locall bloodl pressurel andl bloodl flowl Byl changingl diametersl ofl afferentl arterioles,l efferentl arterioles,l andl glomerularl capillaries *Juxtamedullaryl apparatus*
Reducedl bloodl flowl orl glomerularl bloodl pressurel triggers:
Dilationl ofl afferentl arteriole Dilationl ofl glomerularl capillaries Constrictionl ofl efferentl arterioles *Whenl bloodl pressurel isl lowl whatl shouldl happenl tol thel afferentl andl efferentl arteriolesl
:Afferentl willl dilate.l Efferentl willl constrict*
*Whenl bloodl pressurel isl highl afferentl willl constrictl andl efferentl willl dilate*
Q:l Summarizel howl GFRl isl regulatedl byl thel autonomicl nervousl system.l Includel thel effectsl ofl exercisel inl yourl response.
Answer:
Sympatheticl activation:
Constrictsl afferentl arterioles Fightl orl flightl exercising Decreasesl GFRl Slowsl filtratel production Decreasesl bloodl flowl tol thel glomerulus i.e.l Exercisel -l problemsl forl triathletes
- / 4