Matayoshi 10-9-07

Front 1

Reabsorption = Filtration - what

Back 1

Excretion

Front 2

Filtration of x = GFR * what

Back 2

plasma concentration of x

[x]

Front 3

excretion of x = urine flow (V) * what

Back 3

urine concentration of x

[x]

Front 4

Secretion = Excretion - what

Back 4

Filtration

Front 5

If you have a negative Reabsorption, then you have no ___ reabsorption,

but you do have ____ secretion

Back 5

net

Front 6

Glomerular filtration is largely ___-selective.

Back 6

non

Front 7

Tubular reabsorption is highly _____

Back 7

selective

Front 8

How do you tell proximal tubule from distal tubule?

Back 8

microvilli

Front 9

Tubular cells use a ___-port pump for glucose and Na

Back 9

sym

Front 10

Tubular cells use a ___-port pump for H+ and Na

Back 10

anti

Front 11

Creatinine is permeable or impermeable to the tubular membrane

Back 11

impermeable

Front 12

chloride is transported across the luminal membrane with sodium by _______active transport

Back 12

secondary

Front 13

Sodium travels in Both trans and paracellular routes with membrane potential of about ______mV.

Back 13

-70mV

Front 14

There are sodium carriers on luminal surfaces in ____ border

Back 14

brush

Front 15

Water moves into peritubular capillaries via _____ filtration (bulk flow).

Back 15

ultra

Front 16

Tubular cells use a ___-port pump for amino acids and Na

Back 16

sym

Front 17

Large proteins are absorbed in the proximal tubule via __________.

Back 17

pinocytosis

Front 18

the tubular load at which transprot maximum is exceeded in some nephrons.
This is not exactly the same as the transport max of the whole kidney b/c some nephrons have lower transport max's than others.

Back 18

Threshold

Front 19

A uninephroectomized pt with uncontrolled DM has a GFR of 90ml/min, a plasm glu of 200 mg/dl (2mg/ml), and a transport max of 150 mg/min. What is the glucose excretion for this pt?

Back 19

30 mg/min



Filt of glu = GFR * plasma conc of glu

Excr = Filt - reabsorp
Excr = Filt - transport max

Front 20

Where does most reabsorption occur?

What is exception?

Back 20

Proximal tubule

Exception: Mg ion is reabsorbed in thick ascending loop of Henle

Front 21

Where does most secretion occur?


What is exception?

Back 21

proximal tubule

exception: K+ is secreted in late distal tubule by principal cells

Front 22

H+ ion is secreted. What is reabsorbed as a result?

Back 22

H2O and CO2


(b/c H+ is buffered by bicarbonate, and carbonic acid is split to CO2 and H2O by carbonic anhydrase)

Front 23

Why is phosphate a good intracellular buffer but a poor blood buffer?

Back 23

?

Front 24

As fluid moves thru proximal tubule, what things decrease in concentration?

Back 24

Amino Acids
Glucose
HCO3

Front 25

As fluid moves thru proximal tubule, what things increase in concentration

Back 25

Creatinine
Urea
Chloride-

Front 26

Whys does Na+ concentration remain constant?

Back 26

b/c osmolality remains constant

Front 27

PAH is used to measure ____ flow

Back 27

RPF

Front 28

Loop of Henle – Water and sodium reabsorption though _______ exchange.

Back 28

countercurrent

Front 29

Descending thin limb is highly permeable to water and moderately permeable to urea and ____

Back 29

sodium

Front 30

Thin ascending limb is impermeable to water and has some permeability to Ca++, bicarbonate and ________. Permeable to Na++

Back 30

magnesium

Front 31

Thick limb is highly metabolic with active reabsorption of _____(3) through secondary active transport.

Back 31

sodium, potassium and chloride

Front 32

Thick limb:

Also Ca++ Mg++ and bicarbonate are highly reabsorbed here. Impermeable to _____

Back 32

water

Front 33

20% of filtered water is reabsorbed in the loop of Henle mainly in the ______ limb

Back 33

descending

Front 34

25% of filtered Na+, K+ and CI- is reabsorbed in the loop of Henle mainly in the _______ thick limb.

Back 34

ascending

Front 35

What is "The diluting segment"?

Back 35

Early distal tubule

Front 36

thiazides inhibit the Na/Cl symport where?

Back 36

early distal tubule

Front 37

Maximal urine concentration

Back 37

1200-1400 mOsm / L


sp gr ~ 1.030

Front 38

Minimal urine concentration

Back 38

50-70 mOsm / L

Front 39

the countercurrent multiplier region of the kidney

Back 39

medulla

Front 40

Glomerular filtrate is isotonic.
Pre-urine passing through the proximal tubule remains isotonic. Why?

Back 40

?

Front 41

What is the urine osmolarity in the three parts of the loop of Henle?

Back 41

Descending thin limb- the fluid becomes more hypertonic

Ascending thick limb- the fluid becomes more hypotonic… Why?

Front 42

b. Active transport of ions takes place in the ascending thick limb. This transport is a unique symport system and is a necessary component in maintaining the __________ multiplier

Back 42

countercurrent

Front 43

the thick ascending limb is sometimes referred to as a “diluting segment” because of the removal of solute. This label is however is more classically applied to the ________.

Back 43

early distal tubule

Front 44

There is an obligatory urine volume.
For 70kg human: ____mOsm of solute/ day must be excreted to maintain electrolyte balance

Back 44

600mOsm

Front 45

There is an obligatory urine volume.

If the max urine osmolarity is 1200 mOsm/l and 600 mOm/day must be excreted (for a 70kg human), what is urine volume per day?

Back 45

0.5 L/day

Front 46

Countercurrent multiplication
1. Requires the special arrangement of loop of Henle and vasa _____

Back 46

recta

Front 47

Countercurrent multiplication
2. Requires active transport of Na+ and co-transport of K+ and C1- in __________ limb.

Back 47

thick ascendingCountercurrent multiplication

Front 48

Countercurrent multiplication
3. Requires active transport of ions from the collecting ducts into the

Back 48

interstitium

Front 49

Countercurrent multiplication
4. Requires the movement of urea from the medullary collecting duct into the interstitum by bulk flow (in the presence of _____).

Back 49

ADH

Front 50

6. What are the tubular characteristics of the loop of Henle relative to urea? What is the importance of this characteristic?

Back 50

virtually impermeable to urea

Front 51

Urea is passively reabsorbed in the __________

Back 51

proximal tubule

Front 52

In the presence of ADH, water is reabsorbed in distal and collecting tubules, concentrating ____ in these parts of the nephron

Back 52

urea

Front 53

The inner medullary collecting tubule is highly permeable to urea, which diffuses into the medullary _______

Back 53

interstitium

Front 54

ADH increases urea permeability of medullary ___________ tubule.

Back 54

collecting tubule

Front 55

Vasa recta blood flow is low (only ___ % of total renal blood flow)

Back 55

1-2

Front 56

Early Distal Tubule:
-Functionally similar to thick ascending loop
-Not permeable to _____ (called diluting segment)
Active reabsorption of Na+, Cl-, K+, Mg++
Contains macula densa

Back 56

water

Front 57

Early Distal Tubule:
-Active reabsorption of ____(4 ions)
-Contains macula densa

Back 57

Na+, Cl-, K+, Mg++

Front 58

Na channel blockers that inhibit Na reabsorption in collecting tubule by blocking Na channels in the lumen side of Principal cells

Back 58

Amiloride
Triamterene

Front 59

Aldosterone blockers that inhibit Na reabsorption in collecting tubule

Back 59

Spironolactone
Eplerenone

Front 60

Intercalated cells reabsorb ___ and secrete H+.

Back 60

K+

Front 61

Principal cells reabsorb Na+ and water and secrete ___.

Back 61

K+

Front 62

ADH regulates water permeability. Aldosterone regulates Na+ reaborption and ___ secretion.

Back 62

K+

Front 63

What is meant by potassium-sparing and how are sodium channel blocking and aldosterone antagonist type diuretics involved?

Back 63

?