Jan3 M1-GFR

Question 1

cortex content

Answer 1

glomeruli, tubules

Question 2

medulla content

Answer 2

collecting ducts, loop of Henle

Question 3

embryo of nephron

Answer 3

two types of cells join in DCT

Question 4

3 filtration layers at glomerulus from inside capillary to outside

Answer 4

endothelial layer, BM layer, foot processes of podocytes

Question 5

podocytes are what

Answer 5

specialized epithelial cells

Question 6

what filtrate does not contain

Answer 6

cells, proteins, fats*

Question 7

max size of molecules going in filtrate

Answer 7

70 kDa (70 kg per mol)

Question 8

albumin size + why not in filtrate

Answer 8

62 kDa. is negative. BM and podocytes are negative.

Question 9

albumin of urine sign of what + 2 things that might have happened

Answer 9

glomerular disease.

damage to one of 3 layers OR loss of negative charge

Question 10

how filterability of a substance varies with size and charge

Answer 10

less with bigger size.

positive > neutral > negative

Question 11

clearance def

Answer 11

how much of a substance is removed from the circulation by the kidney and put into urine per unit time

Question 12

GFR formula

Answer 12

K((Pgc - Pt) - (OPgc - OPt) = GFR

Question 13

K in GFR formula

Answer 13

ultrafiltration coefficient (total capillary area available for filtration)

Question 14

what can affect K

Answer 14

glomerular disease, immune complex deposition

Question 15

what can affect Pgc

Answer 15

aff and eff R, diabetes, htn, CKD

Question 16

what can affect Pt

Answer 16

tubular obstruction

Question 17

what can affect OPgc

Answer 17

hypoalbuminemia, nephrotic syndrome

Question 18

creatinine origin

Answer 18

creatine in muscle converted to Cr

Question 19

Cr values needed to get GFR (or Crcl): what’s the formula

Answer 19

GFR x plasma conc Cr = urine conc Cr x urine volume

Question 20

what urine volume to use in crcl or GFR formula

Answer 20

24 hour urine collection

Question 21

how Cr varies with GFR

Answer 21

lower GFR = higher Cr (blood!!)

Question 22

stage 1 CKD def

Answer 22

kidney damage, normal GFR, above 90

Question 23

stage 2 CKD def

Answer 23

kidney damage, mild drop in GFR, 60-89

Question 24

stage 3 CKD def

Answer 24

moderate drop in GFR. 30-59

Question 25

stage 4 CKD def

Answer 25

severe drop in GFR. 15-29

Question 26

stage 5 CKD def

Answer 26

ESRD. less than 15.

Question 27

stage 5 CKD meaning

Answer 27

dialysis or need for dialysis or pre-dialysis

Question 28

urinary creatinine qt for males and females

Answer 28

males 0.2 mmol per kg daily | females 0.15 mmol per kg daily

Question 29

urinary creatinine used for what

Answer 29

check if complete 24 hr urine collection is done

Question 30

real way of determining GFR

Answer 30

Cockroft Gault formula: use serum Cr only | (140-age)xweightx(1.2 if male)div.serum Cr

Question 31

2 things to note about Cr and GFR

Answer 31

1. have to be in steady state | 2. CrCl overestimates GFR bc Cr secreted in PCT

Question 32

normal GFR

Answer 32

100 ml per min

Question 33

things that can affect Cr production (2)

Answer 33

meat intake and age (less muscle mass)

Question 34

urea origin and absorption in tubule

Answer 34

comes from a.a metab | PCT

Question 35

urea vs GFR

Answer 35

inversely proportional

Question 36

urea and Cr in hypovolemia

Answer 36

urea rises much more than Cr so can assess patients with acute renal failure

Question 37

range of renal autoregulation

Answer 37

BP 80 to 160

Question 38

renal autoregulation goal

Answer 38

maintain GFR

Question 39

renal autoregulation 5 components

Answer 39

myogenic, ATII (RAAS), SS, PGs, TG feedback

Question 40

myogenic reflex of autoregul

Answer 40

low BP: AA dilates and EE constricts | high BP: AA constricts and EE dilates

Question 41

components of juxtaglomerular apparatus

Answer 41

1. macula densa cells of the DCT in contact with AA | 2. juxtaglomerular cells (modified SM cells) in AA

Question 42

TG feedback (3 steps)

Answer 42

1. macula densa cells sense NaCl in DCT 2. if too low, produce NO to dilate AA 3. juxtaglomerular cells release renin if BP is low (sense low volume)

Question 43

vasoconstriction in renal autoregul

Answer 43

SS reaction to drop in BP (SS: epinephrine causes vasoconstriction)

Question 44

ATII (RAAS) in renal autoregul

Answer 44

renin leads to ATII prod. | ATII constricts EA more than AA

Question 45

PGs in renal autoregul

Answer 45

PGs dilate the AA to preserve GFR

Question 46

NSAIDs and GFR

Answer 46

NSAIDs block PGs so drop GFR