M1: U2 Renal Physiology

Question 1

composes 60-90 percent of nitrogenous material in urien

Answer 1

urea

Question 2

nitrogenous substance from muscle tissue

Answer 2

creatinine

Question 3

from nucleic acid catabolism, forming renal calculi

Answer 3

uric acid

Question 4

high in high vegetable diet

Answer 4

hippuric acid

Question 5

principal salt in urine

Answer 5

NaCl

Question 6

portion of the plasma filtered by the glomeruli

Answer 6

renal blood flow/ renal plasma flow

Question 7

ability of kidney to remove excess solutes, water and waste from plasma, measured as volume of plasma per unit time

Answer 7

renal clearance

Question 8

characteristics of substances that can be used for clearance tests

Answer 8

1. neither reabsorbed nor secreted
2. excreted solely through glomerular filtration
3. stable in urine for 24 hrs
4. constant plasma concentration
5. readily available in body
6. has tests for plasma and urine

Question 9

earliest test for GFR

Answer 9

urea clearance

Question 10

why is urea not the substance of choice

Answer 10

40-60 % reabsorbed
affected by protein intake
affected by urine flow rate

Question 11

the slower the urine flow rate is, the ____ urea is reabsorbed

Answer 11

more

Question 12

routine screening for GFR test

Answer 12

creatinine clearance

Question 13

disadvantage of creatinine clearance

Answer 13

1. depends on muscle mass and metabolism
2. 7-10% secreted by PCT
3. secretion blocked by cimetidine, cephalosporin, salicylates, trimethoprim
4. Jaffe method for plasma is non specific
5. affected by bacterial decomposition

Question 14

specimen for creatinine clearance

Answer 14

24 hr urine
plasma collected midway through urine collection

Question 15

creatinine clearance formula

Answer 15

urine/plasma creatinine × urine volume/1440 mins × 1.73/BSA

Question 16

body surface area formula

Answer 16

log BSA = (0.425 × logW) + (0.725 × logH) - 2.144

Question 17

Refenrece values for creatinine clearance

Answer 17

Males: 107- 139 ml/min
Females: 87 - 107 ml/min

Question 18

Other tests for glomerular filtration rate

Answer 18

beta 2 microglobulin
cystatine
inulin
radionucleotides

Question 19

single polypeptide chain that is an HLA component of all nucleated ces

Answer 19

beta 2 microglobulin

Question 20

renal processing of B2 microglobulin

Answer 20

constant concentration in all body fluids – all passes through GFB – all are reabsorbed

therefore if increased in plasma – decreased GFR

Question 21

potential marker for long term monitoring of renal function

Answer 21

cystatin

Question 22

renal processing or cystatin

Answer 22

passes through GFB > reabsorbed > catabolized > does not return to blood

Question 23

cystatine advantage and disadvantage

Answer 23

not affected by age or gender
higher costs and intraindividual variability

Question 24

extremely stable exogenous polymer of fructose that is the reference method for renal clearance test

Answer 24

inulin

Question 25

can be used to visualize glomerular filtration

Answer 25

radionucleotides

Question 26

test for renal concentrating ability

Answer 26

tubular reabsorption test

Question 27

Two types of tests for tubular reabsorption

Answer 27

conventional method modern methods

Question 28

2 conventional methods for tubular reabsorption

Answer 28

Fishberg concentration test Mosenthal concentration test

Question 29

test that makes use of fluid deprivation

Answer 29

Fishberg concentration test

Question 30

how many hours is the fluid restriction for the Fishberg concentration test

Answer 30

at least 24 hrs

Question 31

normal patients have a urine specific gravity of ____ after 24 hr fluid deprivation

Answer 31

>1.025

Question 32

conventional method for tubular reabsorption that has no fluid and diet restriction

Answer 32

Mosenthal concentration test

Question 33

What urine samples are collected for Mosenthal concentration test

Answer 33

Two 12 hr urine samples in the day and in the night

Question 34

The night time urine specific gravity of a healthy person in the Mosenthal concentration test should be ____

Answer 34

>1.018

Question 35

Modern methods of tubular reabsorption test

Answer 35

1. osmolality 2. specific gravity 3. free water clearance

Question 36

measurement of the number of solute particles per kilogram of solvent

Answer 36

osmolality

Question 37

osmolality of urine is measured through ____

Answer 37

colligative properties

Question 38

4 colligative properties used to measure osmolality of urine

Answer 38

1. freezing point 2. vapor pressure 3. boiling point 4. osmotic pressure

Question 39

two colligative properties that are inversely proportional to the osmolality of a sample

Answer 39

1. freezing point 2. vapor pressure

Question 40

two colligative properties that are directly proportional to osmolality of sample

Answer 40

boiling point osmotic pressure

Question 41

temperature sensitive probe using heat of fusion to determine freezing point

Answer 41

thermistor

Question 42

determines heat of condensation for vapor pressure measurement

Answer 42

thermocouple

Question 43

principal solute for urine osmolality

Answer 43

urea

Question 44

principal solute for blood osmolality

Answer 44

NaCl

Question 45

osmolality of initial ultrafiltrate

Answer 45

300 mosm/kg

Question 46

normal serum osmolality

Answer 46

275-300 mosm/kg

Question 47

normal random urine osmolality

Answer 47

50-1400 mosm/kg

Question 48

normal urine to serum osmolality ratio

Answer 48

1:1

Question 49

urine to serum osmolality ratio during controlled fluid intake

Answer 49

2:1

Question 50

1 mol of non ionizing substance lowers 1 kg of H20 freezing point by ____

Answer 50

1.86

Question 51

diabetes with higher osmolality

Answer 51

diabetes mellitus

Question 52

diabetes with lower osmolality

Answer 52

diabetes insipidus

Question 53

initial osmolarity of patient with polyuria is <200 mmol/kg

Answer 53

water diuresis

Question 54

initial osmolarity of patient with polyuria is ~300 mmol/kg

Answer 54

solute diuresis

Question 55

test after determining that polyuria is caused by water diuresis

Answer 55

fluid deprivation test

Question 56

tests after determining cause of polyuria as solute diuresis

Answer 56

plasma glucose and urea

Question 57

> 800 mmol/kg after fluid deprivation test

Answer 57

caused by excessive fluid intake

Question 58

< 800 mmol/kg after fluid deprivation test

Answer 58

additional 2 hrs of fluid deprivation

Question 59

urine still < 800 mmol/kg after additional 2 hrs deprivation

Answer 59

ADH challenge (synthetic ADH)

Question 60

normal response/ hyper osmolal after ADH challenge

Answer 60

neurogenic diabetes insipidus

Question 61

no response/ hypoosmolal after ADH challenge

Answer 61

nephrogenic diabetes insipidus

Question 62

high plasma glucose causing solute diuresis

Answer 62

diabetes mellitus

Question 63

normal plasma glucose in solute diuresis

Answer 63

Na or mannitol diuresis

Question 64

high urea in solute diuresis

Answer 64

hypercatabolism or renal disease

Question 65

typical fluid deprivation protocol

Answer 65

6 pm to 8 am additional 2 hrs - 8 am to 10 am

Question 66

expression of density of urine relative to density of water

Answer 66

specific gravity

Question 67

based on number and mass of solutes in sample

Answer 67

specific gravity

Question 68

osmolality or specific gravity: affected by number of solutes only

Answer 68

osmolality

Question 69

osmolality or specific gravity: affected by number and mass of solutes

Answer 69

specific gravity

Question 70

osmolality or specific gravity: each particle contributes equally

Answer 70

osmolality

Question 71

osmolality or specific gravity: some solutes contribute more due to mass

Answer 71

specific gravity

Question 72

osmolality or specific gravity: influenced by glucose and protein

Answer 72

specific gravity

Question 73

osmolality or specific gravity: not affected by glucose and protein

Answer 73

osmolality

Question 74

range of physiologically possible specific gravity values

Answer 74

1.001 to 1.040

Question 75

two possible reasons why SPG can be greater than 1.040

Answer 75

mannitol infusion radiographic contrast media

Question 76

unchanging specific gravity

Answer 76

isosthenuria

Question 77

maximum spg detected by rgt strip

Answer 77

1.030

Question 78

max spg detected by refractometer

Answer 78

1.050

Question 79

assess how kidney responds to body hydration status

Answer 79

free water clearance

Question 80

deyermine quantity of water NOT REABSORBED by the kidney

Answer 80

free water clearance

Question 81

volume of plasma that is cleared of free water per minutes

Answer 81

free water clearance

Question 82

free water clearance formula

Answer 82

urine volume - osmolar clearance

Question 83

volume of water that must be cleared to produce urine with the same osmolality as plasma

Answer 83

osmolar clearance

Question 84

osmolar clearance formula

Answer 84

OC = (urine osmolality/ plasma osmolality) urine volume

Question 85

when total urine volume = clearance volume

Answer 85

isoosmotic urine (no renal concentration or dilution)

Question 86

urine osmolality is less than serum osmolality total urine volume cleared is greated than osmolar clearance

Answer 86

hypoosmotic urine (excess diuresis) positive number

Question 87

urine osmolality is greater than serum osmolality, total urine volume is less rhan osmolar clearance

Answer 87

hyperosmolal urine (lower diuresis) negative number