Test 2: Wk6: 1 Renal transport mechanisms and clearance - Mangiarua

Question 1

3 basic renal processes

Answer 1

1 glomerular filtration
2 tubular secretion
3 tubular reabsorbtion

Question 2

Glomerular filtration

Answer 2

bulk-flow of essentially protein-free plasma from the

glomerular capillaries into Bowman’s capsule.

Question 3

Glomerular filtration is what type of transport

Answer 3

passive; no active

Question 4

Tubular secretion

Answer 4

transfer of materials from the peritubular-capillary plasma to the
tubular lumen

Question 5

Tubular secretion transport

Answer 5

Both active and passive transport

Question 6

Tubular secretion selectivity

Answer 6

high

Question 7

tubular secretion occurs where

Answer 7

throughout the length of the nephron

Question 8

Tubular reabsorption

Answer 8

transfer of materials from the lumen of the tubule to the

peritubular-capillary plasma.

Question 9

Tubular reabsorption selectivity

Answer 9

high

Question 10

Tubular reabsorption transport

Answer 10

Both active and passive transport

Question 11

tubular reabsorption occurs where

Answer 11

throughout the length of the nephron

Question 12

— charged macromolecules are
restricted far more than —molecules, while — charged molecules
are restricted less.

Answer 12

negative, neutral, positive

Question 13

As molecular weight (and therefore size) —, filterability —, so
that proteins with a molecular weight above — d are hardly filtered at all.

Answer 13

increase, declines, 70,000

Question 14

best index of kidney function

Answer 14

GFR

Question 15

GFR 60-89

Answer 15

mild kidney dz

Question 16

GFR 30-59

Answer 16

Moderate chronic renal insufficiency

Question 17

GFR 15-29

Answer 17

Severe chronic renal insufficiency

Question 18

GFR <15

Answer 18

End Stage Renal Failure

Question 19

Renal Clearance

Answer 19

volume of plasma from which all of a substance has been removed and excreted into urine per unit time

Question 20

What is used for Measurement of GFR

Answer 20

inulin

Question 21

— is freely filtered at the glomerulus and not reabsorbed or secreted into tubule

Answer 21

inulin

Question 22

GFR =

Answer 22

urine flow x inulin conc. urine / inulin conc. plasma

GFR = V x Uin / Pin

Question 23

In order to determine the rate at which plasma is filtered into Bowman’s space, a chemical which meets the following criteria is used (6)

Answer 23

1) Not bound to plasma proteins.
2) Not electrically charged.
3) Freely filtered.
4) Not lost by reabsorption from tubular fluid to peritubular fluid.
5) Not gained by secretion from peritubular fluid into tubular fluid.
6) All that is filtered is excreted.

Question 24

Clearance of Inulin

Answer 24

GFR = Uin x V / Pin = Cin

Question 25

Inulin clearance refers to the

Answer 25

Inulin clearance refers to the milliliters of plasma from which all inulin has been removed by the kidney each minute

Question 26

Inulin clearance is independent of

Answer 26

plasma inulin conc. and urine flow

Question 27

Creatinine

Answer 27

endogenous substance that estimates GFR

Question 28

Clearance of Creatinine

Answer 28

GFR = Ccr = Ucr x V / Pcr

Question 29

Creatinine — GFR

Answer 29

slightly overestimates

Question 30

— concentration is used to follow pts over long period of chronic renal dz

Answer 30

Creatinine

Question 31

Renal Clearance Ca =

Answer 31

Ca = Va x V / Pa

Question 32

Ca > Cin

Answer 32

cleared by filtration and secretion

Question 33

Cb < Cin

Answer 33

some of b is reabsorbed

Question 34

Diffusion:

Answer 34

• requires an electrochemical gradient,

* “downhill” transport

Question 35

Facilitated diffusion:

Answer 35

requires an electrochemical gradient + carriers; exhibits
specificity, saturability, and competition,
• “downhill” transport.

Question 36

Primary active transport

Answer 36

requires carriers; exhibits specificity, saturability, and
competition,
• “uphill” transport. Requires energy; splitting of ATP.

Question 37

Secondary active transport

Answer 37

• requires carriers; exhibits specificity, saturability, and
competition,
• one substance “downhill” transport, the other “uphill”
transport,
• cotransport (or symport),
• countertransport (or antiport).

Question 38

diffusion between cells

Answer 38

paracellular

Question 39

“across” the cell

Answer 39

transcellular

Question 40

— used for measurement of effective renal plasma flow

Answer 40

PAH

Question 41

PAH is filtered —

Answer 41

at glomerulus

Question 42

PAH undergoes no significant

Answer 42

tubular reabsorbtion

Question 43

— can be used to estimate RPF (Renal Plasma Flow)

Answer 43

Clearance of PAH

Question 44

PAH is a foreign compound so it needs to be

Answer 44

infused

Question 45

ERPF

Answer 45

Effective Renal Plasma Flow

Question 46

ERPF =

Answer 46

ERPF = CPAH = V x UPAH / PPAH

Question 47

the effective renal plasma flow Underestimates true RPF by —%

Answer 47

10%

Question 48

The actual renal plasma flow can be obtained by dividing the — by —

Answer 48

ERPF by excretion ratio of PAH

Question 49

equation for calculation RPF

Answer 49

E = A - V / A

A conc. in renal arterial plasma
V conc. in renal venous plasma

Question 50

Urate filterability

Answer 50

free

Question 51

more than 90% if filtered urate is reabsorbed where

Answer 51

early in prox tubule

Question 52

urate secretion

Answer 52

active tubular secretion in late prox tubule

Question 53

urate is — regulated

Answer 53

homeostatically

Question 54

urate undergoes both — and —

Answer 54

active reabsorption and active secretion

Question 55

K filterability

Answer 55

free

Question 56

67% of K reabsorbed in

Answer 56

prox tubule

Question 57

20% of K is reabsorbed in

Answer 57

TAL of LOH

Question 58

— is reabsorbed or secreted in the late nephron depending on diet

Answer 58

K

Question 59

K is — regulated

Answer 59

homeostatically

Question 60

Reabsorption rate =

Answer 60

Filtered load – Excretion rate

Question 61

Secretion rate =

Answer 61

Excretion rate – Filtered load

Question 62

Filtered load =

Answer 62

GFR x [plasma]

Question 63

Excretion rate =

Answer 63

V x [urine]