nephrons.pdf

nephrons

1. NEPHRON

4. THE NEPHRON
✓Eachkidneyconsistsofabout1millionbasic
structuralandfunctionalunitscallednephrons
wherebloodfilteringandurineformationoccur.
✓Eachnephroniscomposedof10parts–Afferent
Arteriole→Glomerulus→Bowman'sCapsule
→EfferentArteriole→ProximalConvoluted
Tubule(PCT)→DescendingLimbOfLoopOf
Henle→VasaRecta→AscendingLimbOf
LoopOfHenle→DistalConvoluted
Tubule(DCT)→CollectingDuct.

10. NEPHRON ANATOMY
1.Renalcorpuscle–theheadofthenephron.
TherenalcorpuscleiscomposedofBowman’s
capsuleandglomerulus
▪Bowman’s capsuleisthecoverofthe
corpusclethatsurroundstheglomerulus(cup
shaped)
▪Theglomerulusisthenetworkofcapillaries
foundinsidethecorpuscle
2.Renaltubule–thetubularpassagewayofthe
nephron

11. Glomerulus
The glomerulus is
surroundedbyBowman's
capsule
Itisanetworkofcapillaries
thatperformsthefirststep
offilteringblood.
Operatesasanonspecific
filter-removesbothuseful
andnon-usefulmaterial

12. Afferent and Efferent arteriole
Afferentarterioleisa
branchoftherenalartery
thatbringsinbloodtothe
glomerulus.
Efferentarterioleisa
branchoftherenalartery
thatdrainsbloodaway
fromtheglomerulus.

13. Bowman’s Capsule
Itisdoublewalledcup-
shaped.
Asacthatencloses
glomerulus
Transfersfiltratefrom
theglomerulustothe
Proximal Convoluted
Tubule(PCT)

14. Proximal Convoluted Tubule (PCT)
LowerpartofBowman’scapsuleleadsintoPCT.
Itliesintherenalcortex.
PCTislinedbycuboidalepithelialhavingbrush
borderswithlongmicrovilliforincreasingabsorptive
areathatreabsorbsmostoftheusefulsubstancesof
thefiltrate:sodium(65%),water(65%),bicarbonate
(90%),chloride(50%),glucose.
Theprimarysiteforsecretion(excretion)ofdrug
wasteandhydrogenions.

16. The loop of Henle
U-shapedtubethatconsistsofa
descendinglimbandanascending
limb.
Beginsinthecortex,receiving
filtratefromthePCT,extendsinto
themedulla,andthenreturnsto
thecortextoemptyintothedistal
convolutedtubule(DCT).

17. Descending Limb of the Loop of Henle
Fullypermeabletowaterandcompletely
impermeabletosolutes(saltparticles).
ReceivesfiltratefromthePCT,allowswatertobe
absorbedandpasses“salty”filtratetothenext
segment.
“Saveswaterandpassesthesalt”
Thepassingfiltratebecomesconcentrated.

19. Ascending Limb of the loop of Henle
Impermeable to water and actively transports
(reabsorbs) salt (NaCl) to the interstitial fluid of
the pyramids in the medulla.
“Saves salt and passes the water.”
The passing filtrate becomes dilute.

21. Distal Convoluted Tubule (DCT)
It is highly coiled part of nephron.
Variably active portion of the nephron.
Receives dilute fluid from the ascending
limb of loop of henle.

23. Collecting Duct
Variably active portion of the Nephron
Lined by specialized cuboidalepithelial with
very few microvilli.
Receives fluid from DCT.
The last segment to save water for the body.

30. Series of Blood Vessels In Kidney

31. Functions of Nephron
1.Nephronremoveureaanduricacidfromthe
blood
2.Nephronregulatebloodpressure.
3.Nephronalsoremovepigments,drugs,poisons,
excessvitaminsfromtheblood.
4.Itregulatestheamountofmineralsaltsinthe
body.
5.AlsoregulatebloodpH.