Loop of Henle Flashcards

1
Q

what does the liver do to lipid soluble drugs and pollutants to facilitate their excretion

A

makes them polar (water soluble)

guess this makes it easier for them to be secreted and excreted from osmotic pressures etc

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2
Q

fluid in proximal tubule is iso/hypo/hyper osmotic to plasma

A

isosmotic

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3
Q

what is the osmolarity of plasma

A

300mOsmoles/L

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4
Q

how are do proximal tubule and plasma have the same osmolarity

A

because all movements have been accompanied by H20 movements

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5
Q

where are the proximal and distal tubules, cortex or medulla

A

cortex

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6
Q

what does the loop of henle do

A

concentrates urine

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7
Q

what is the minimum concentration of urine that can be produced

A

30-50mOsmoles/L (10 times weaker than plasma)

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8
Q

which loops of henle establish a hypertonic medullary gradient

A

ones in the medulla. i.e. belonging to juxtamedullary nephrons

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9
Q

which limb of henle loop is impermeable to H2O

A

ascending limb

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10
Q

permeabilities of descending limb

A

H2O permeable

NaCl impermeable

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11
Q

which limb of henle loop is impermeable to NaCl

A

descending limb

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12
Q

which limb of henle loop is permeable to NaCl

A

ascending limb

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13
Q

effect of ascending limb on concentration

A

reduces concentration (pumps out NaCl)

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14
Q

which limb of henle dilutes the fluid

A

ascending

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15
Q

which limb of henle concentrates the fluid

A

descending

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16
Q

when water moves out of descending limb into interstitium where does it go from there

A

it is reabsorbed into the vasa recta by oncotic pressure

17
Q

once water moves out of descending limb into interstitium where does it go from there

A

it is reabsorbed into the vasa recta by oncotic pressure

18
Q

describe the process of concentration in the loop of henle

A

ascending limb actively pumps out NaCl making the interstitial fluid more concentrated and the tubule more dilute.
the descending limb dilutes the interstitial fluid by moving out water.
but the ascending limb just keeps on pumping out more and more salt and the descending limb keeps on losing water to it.
fluid is most concentrated at end of descending.

19
Q

if the active transport of NaCl doesn’t happen what is the conc of urine like

A

isotonic i.e. 300mOsmoles/L

20
Q

what’s more dilute, distal tubule or plasma

A

distal tubule (100 compared to 300)

21
Q

effect of loop of henle on interstitium

A

it makes it increasingly concentrated

22
Q

what difference exist between the limbs at the same horizontal level

A

200mOsmole/L

23
Q

what is the vasa recta

A

arrangement of peritubular capillaries of juxtamedullary nephrons

24
Q

true/false capillaries are only freely permeable to H2O giving them a different osmolarity to the interstitium around them

A

false - they are freely permeable to all solutes and H2O and so equilibrate with interstitium

25
Q

true/false vasa recta interfere with interstitial gradient

A

false - they do not disturb it

26
Q

3 functions of vasa recta

A
  1. provide O2 for medulla
  2. not disturbing gradient
  3. remove volume from interstitium
27
Q

vasa recta has high/low flow rate

A

low flow rate - allows time for equilibration to occur

28
Q

where is water regulated

A

collecting duct

29
Q

what hormone control water regulation

A

Anti-Diuretic Hormone (Vasopressin)