The document discusses the structure and function of the kidney and osmoregulation. It defines key terms and outlines the processes of ultrafiltration, selective reabsorption and countercurrent exchange in the kidney. These processes allow the kidney to regulate water balance and remove nitrogenous wastes from the blood through excretion of urine, while reabsorbing useful solutes like water, glucose and amino acids. The kidney is crucial for homeostasis and is able to adapt its functions through feedback mechanisms and hormones like ADH to maintain the proper osmolarity and solute concentrations in the blood during dehydration, overhydration and other health issues.

1. IB Biology SL 11.3 The Kidney&Osmoregulation Name:
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Topic 11.3 The Kidney & Osmoregulation
1) Define the followingterms.
Excretion
Homeostasis
Osmolarity
Osmoregulators
Osmoconformers
Ultrafiltration
2) Outline hownitrogenouswastesare formed. Whatisthe product?
3) What isthe formof nitrogenouswastes excretedin:
Fish Birds Insects Mammals
4) Explainhownitrogenouswastesare excretedinarthropods(insects).
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5) Compare and contrastbloodinthe renal artery andthe renal vein.

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6) Draw and label adiagramof the humankidney.Include- cortex,medulla,pelvis,ureter,renal
vein,&renal artery.
7) Outline the functionsof the kidney.
8) Annotate adiagram of a nephron. Include glomerulus,Bowman’scapsule,proximal
convolutedtubule,loopof Henle,distal convolutedtubule,collectingduct.

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9) Outline howthe structure of the glomerulusisrelatedtoitsfunction.
a. Fenestration
b. Podocytes
c. Basementmembrane
10) Compare and contrastbloodinthe afferentarteriolesof the glomerulustobloodinthe
efferentarteriolesof the glomerulus.
Content (per dm-3
of blood plasma
Solutes Plasma filtrate
Na+
ions (mol)
Cl-
ions (mol)
glucose (mol)
urea (mol)
proteins (mol)
11) Explainthe processof ultrafiltration.
12) Compare and contrastactive transport,cotransport,and osmosis.

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13) Water isreabsorbedinthe proximal convolutedtubule (PCT).State the approximate percent
of waterthat isreabsorbedfromthe filtrate inthe PCT.
14) State two othersubstancesthatare alsoreabsorbedfromthe filtrate inthe proximal
convolutedtubule. Whatpercentof those substancesare reabsorbed?
15) Outline howeachof the followingsubstancesisreabsorbedinthe proximal convoluted
tubule.
Substance How it’s reabsorbed?
Sodium
(Na+
)
Chloride
(Cl-
)
Glucose &
amino
acids
Water
16) Explainselectivereabsorptioninthe kidney.

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17) Annotate the diagramto showthe movementof waterandionsin each part of the loopof
Henle.
18) Describe the permeability(the state orqualityof amembrane thatcausesit to allow liquids
or solutes topass throughit) of the loopof Henle towaterand to ions.
19) ADH (antidiuretichormone) isaglobularproteinproducedinthe posteriorpituitarygland.
Define diuretic:
Define hormone:
Explainthe role of the collectingduct (CD) andADH (vasopressin)incontrollingthe water
balance inthe blood.
Descending
limb
Ascending
limb
Collecting duct

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20) Annotate the diagrambelowinordertoexplainhow osmoregulationusesnegativefeedback
to keepthe solute concentrationof the bloodatthe rightlevel.
21) What doesa longerloopof Henle indicate inanimals?
22) How doesthe looponHenle utilize countercurrentexchange ?
23) Outline the consequencesof dehydrationandoverhydration.
ConsequencesofDehydration Consequencesofoverhydration

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24) Discussthe use of kidneydialysisinthe place of anon-functioningkidney.
25) Outline howthe presence of the followingsubstancesinurine canbe usedtocheck for
healthissues.
Blood cells
Glucose
Proteins
Drugs