chapter 4

Question 1

measures of urine concentration

Answer 1

1. osmolality
2. specific gravity

Question 2

urine composition

Answer 2

normal ranges of volume and solute

Question 3

what effects urine concentration

Answer 3

diet, physical activity, and health

Question 4

osmolality

Answer 4

concentration of particles (solutes) dissolved in urine (particles per unit of water)
–>determined in distal collecting tubules when ADH is present
–> normal urine osmolality is 1-3 times that of plasma

Question 5

specific gravity

Answer 5

measures concentration of urine through density of urine compared to density of water
–> range: 1.002-1.035

Question 6

polyuria

Answer 6

greater than 3 liters a day

Question 7

causes of polyuria

Answer 7

water diuresis: ADH secretion is inadequate or receptors are ineffective
solute diuresis: involves glucose, urea, or sodium

Question 8

oliguria

Answer 8

less than 400 mL a day

Question 9

causes of oliguria

Answer 9

urinary obstruction, tubular dysfunction, and fluid loss

Question 10

anuria

Answer 10

absence or cessation of urine excretion

Question 11

cause of anuria

Answer 11

progressive renal disease or renal failure

Question 12

what does renal concentrating ability tell us

Answer 12

assess tubular function by demonstrating tubules can produce concentrated urine specimen
–> measured through osmolality (solute number)

Question 13

prevalent solutes in urine

Answer 13

1. urea
2. chloride
3. sodium

Question 14

fluid deprivation tests function

Answer 14

differentiates between causes of polyuria due to water diuresis

Question 15

how fluid deprivation tests work

Answer 15

water consumption is restricted and urine is checked 12 hours later
–> if concentrated test ends

Question 16

neurogenic diabetes insipidus

Answer 16

ADH is decreased

Question 17

nephrogenic diabetes insipidus

Answer 17

lack of renal response to ADH

Question 18

renal clearance tests

Answer 18

asses glomerular filtration rate
–> how much plasma goes completely cleared through glomerulus over a certain time

Question 19

glomerluar filtration rate

Answer 19

measures substances removed by glomerular filtration
–> insulin and creatinine (most common)

Question 20

creatinine

Answer 20

waste that is constantly produced and excreted by kidneys

Question 21

measuring creatine clearance

Answer 21

24 hr urine sample and drawing of blood (serum/plasma)

Question 22

advantages of creatinine clearance

Answer 22

easily performed, accuracy and precision methods are well studied

Question 23

disadvantages of creatinine clearance

Answer 23

if nonspecific jaffe method is used, creatinine values will be overestimated –> values close to insulin clearance results

Question 24

estimated glomerular filtration

Answer 24

detects chronic kidney disease
–>used for high risk individuals with diabetes, hypertension, heart disease, or family history of kidney disease

Question 25

accurate values of estimated glomerular filtration rate

Answer 25

most accurate values are less than or equal to 60 mL/min

Question 26

beta-microglobulin

Answer 26

passes through glomeruli and 99.9% of it is reabsorbed by proximal tubules
–> marker of reduced tubular function

Question 27

uses of beta-microglobulin

Answer 27

identifies early kidney transplant rejection
–>differentiates between tubular and glomerular diseases

Question 28

screening for albuminuria

Answer 28

detection of albuminuria appears in diabetic nephropathy
–> early detection allows for additional testing and intervention to prevent diabetes

Question 29

cause of albuminuria presence

Answer 29

increased glomerular permeability
–> changes in glomerular filtration

Question 30

most important factor associated with glomerular proteinuria

Answer 30

hyperglycemia or diabetes mellitus

Question 31

most common test used for GFR

Answer 31

creatinine clearance

Question 32

most common test used for tubular concentrating ability

Answer 32

urine osmolaltiy

Question 33

most common test for glomerular permeability to plasma proteins

Answer 33

urine protein electrophoresis