Kidneys Flashcards Preview

NBDE PART 1 BIOCHEM/PHYSIOLOGY > Kidneys > Flashcards

Flashcards in Kidneys Deck (70):
1

A substance that is filtered into the renal tubules but is then fully reabsorbed:

inulin, glucose, para-aminohippurate (PAH)

glucose

2

a substance that is filtered and secreted, so the entire amount of substrate is released in the first pass:

inulin, glucose, para-aminohippurate (PAH)

PAH

3

a substance that is freely filtered and neither secreted or reabsorbed:

inulin, glucose, para-aminohippurate (PAH)

inulin

4

inulin is a __ that is given by the mouth

starch

5

inulin is freely filtered from the glomerular capillaries into Bowman's capsule but it does not undergo

secretion or reabsorption in the kidney tubules

6

the GFR can be calculated by the clearance of _ from plasma

inulin, glucose, para-aminohippurate (PAH)

inulin (since it is filtered by the kidneys but the kidneys don't do anything to it, don't secrete or reabsorb is)

7

rate at which a substance is cleared from plasma =

volume completely cleared/time = urine concentration of the substance x urine volume/plasma concentration of the substrate

8

if the clearance of a substance that is freely filtered is less than that of inulin then there is a net __

reabsorption of the substance

9

if the clearance of a substance that is freely filtered is greater than that of inulin then there is a net __

secretion of the substance

10

if the clearance of a substance that is freely filtered is equal to that of inulin then there is a net __

then neither secreted or absorbed OR it is both secreted and absorbed in equal amounts

11

para-aminohippurate (PAH) is both

filtered and secreted

12

para-aminohippurate (PAH) is used to estimate

renal plasma flow

13

glucose and NaCl are filtered and

reabsorbed

14

2 other things used to estimate the GFR besides inulin

BUN and serum creatinine

15

the most accurate measure of GFR

serum creatinine

16

___ and __ are what are used to assess if kidneys are functioning well. We produce urea and creatinine at constant rate. So if we excrete the same amount we make, the plasma concentration will remain constant. So if input = output = good. If creatine/Bun rises above normal = suggests kidneys dysfunction input doesn’t equal the output.

Creatinine and urea (bun)

17

most of our nephrons are cortical nephrons or juxtamedullary nephrons

cortical (80%)

18

which one concentrates and dilutes urine
cortical nephrons or juxtamedullary nephrons

juxtamedullary nephrons

19

which one mainly performs excretory and regulatory functins
cortical nephrons or juxtamedullary nephrons

cortical nephrons

20

what part of the nephron is under endocrine control

distal convoluted tubule

21

PTH will make tubule reabsorb more _ and

reabsorb more calcium and excrete more phosphate

22

Aldosterone will make

more sodium reabsorbed and more potassium excreted

23

most secretion in the nephron occurs in what part

proximal tubule

24

about _ of the total amount filtered is reabsorbed in the proximal tubule

2/3

25

kidney secrete/reabsorb H+

secrete

26

kidneys secrete/reabsorb bicarb

reabsorb

27

phosphate compounds and ammonia act as

buffers

28

phosphate ions are excreted along with

cations ex. Na+

29

ammonium ions excreted along with

anions ex. Cl-

30

ammonia is formed in _ cells by the deamination of certain amino acids, especially _

tubular
glutamic acid

31

_ and _ provide good info on how much acid is being eliminated by the kidneys

phosphate and ammonium

32

_ is the best overall index of kidney function

GFR = normally 120mL/minute

33

clinically GFR is evaluated by measuring

plasma creatinine concentration

34

GFR increases:
1. _ of afferent arterioles
2. _ of efferent arterioles
3. _ hydrostatic pressure in Bowman's capsule
4. _ plasma colloid pressure

1.vasodilation
2. vasoconstriction
3. decreased
4. decreased

35

with inulin and creatinine the kidneys do not

reabsorb or secrete them

36

If the kidneys do not reabsorb or secrete a substance, then the GFR =

clearance

37

if the tubules reabsorb the substance, the clearance is _ than the GFR

less than

38

if the tubules secrete the substance, the clearance is _ than the GFR

greater than

39

if the tubules reabsorb AND secrete the substance, the clearance is _ than the GFR

less than, equal to, or greater than the GFR

40

excessive constriction of the afferent arteriole will _ RBF and GFR

decrease

41

the kidney dialysis machine resembles what part of the kidneys system?

countercurrent mechanical system

42

the countercurrent multiplier in the medulla's loop of Henle is dependent on the _ reabsorption of NaCl by the thick ascending loop of Henle

active
thick

43

countercurrent exchange occurs in the region of the peritubular capillary bed called the

vasa recta

44

do the vasa recta create the medullary hyperosmolarity

no

45

the vasa recta prevent the medullary hyperosmolarity from being

dissipated and can carry away water that has been reabsorbed

46

reabsorption of glomerular filtrate would be most affected if modifications were made to the permeability of what section of the nephron

proximal convoluted tubule
bc 2/3 of the glomerular filtrate is reabsorbed in the proximal convoluted tubule

47

almost 100% of the filtered glucose and amino acids are reabsorbed in the

proximal convoluted tubule

48

the filtrate that enters into the proximal tubule from the capillaries are free of

large proteins

49

Excretion rate =

filtrate + secretion - reabsorption

50

how much filtrate does the body make per day

150-250L

51

how much of the filtrate is excreted per day

1-2L of urine per day

52

about _% of filtrate is returned to vascular system and _% is excreted as urine

99%
1%

53

the most important source of ammonia quantitatively is

amino acids

54

what compound is converted to ammonia in the kidney

glutamine

55

from amino acids many tissues but particularly the __ form ammonia by amino transferase and glutamate dehydrogenase reactions

liver

56

from glutamine, the __ form ammonia by the action of renal glutaminase

kidneys

57

amines obtained from diet and monamines that serve as hormones or NT give rise to ammonia by the action of

amino oxidase

58

from purines and pyrimidines amino groups attached to the rings are released as

ammonia

59

urea travels from _ to _

liver to kidneys

60

___ directly catalyzes urea formation in a cell

arginase

61

which of the following processes is not involved in the formation of urine

filtration/reabsorption/excretion/secretion

excretion

62

which 2 involve the most similar amounts of fluid transport
filtration/reabsorption/excretion/secretion

filtration and reabsorption
99% of filtered is reabsorbed

63

which work in the same direction
filtration/reabsorption/excretion/secretion

filtration and reabsorption

64

filtration/reabsorption/excretion/secretion

which is affected by ADH

reabsorption

65

what cannot be filtered

formed elements = cells
and plasma proteins = too large

66

normal urine is
1. clear/cloudy
2. _ color
3. acidic/basic
4. odor of

clear straw colored and slightly acidic and has odor of urea

67

diuresis results from a decrease in tubular

reabsorption of water

68

2 causes of dilute urine

absence of ADH
diabetes insipidus

69

possible causes of concentrated urine

decreased plasma volume
cellular dehydration
DM
excess ADH

70

is a condition characterized by excessive thirst and excretion of large amounts of severely diluted urine, with reduction of fluid intake having no effect on the concentration of the urine

Diabetes insipidus (DI)