ch 5 objectives

Question 1

common terminology used to report normal urine color and clarity

Answer 1

pale yellow, yellow, dark yellow

Question 2

relationship between urochrome and other pigments to normal urine color

Answer 2

urochrome is the pigment that gives urine the yellow color

Question 3

abnormal urine colors and appearance to disease

Answer 3

dark yellow/amber –> bilirubin
pink/red –> blood (hemoglobin + RBCs)
red-purple –> porphyrins
brown –> myoglobin
dark brown –> melanin or homogentisic acid
blue/green –> indican

Question 4

clinical relevance of urine clarity and causes of cloudy urine

Answer 4

nonpathogenic: squamous epithelial cells, contamination, bacterial growth (unpreserved)

pathogenic: RBCs, WBC, bateria, yeasy

Question 5

causes of abnormal urine odor

Answer 5

maple syrup urine disease
ketosis (fruity)
infection

Question 6

explain specific gravity and why measurement is significant in rountine analysis

Answer 6

density of urine compared to density of water
–> evaluation of urine concentration determines kidneys ability to concentrate urine

Question 7

principle of refractometer and advantages of this methodology against reagent strip method

Answer 7

the refractometer measures velocity of light compared to light in a solution (clarity)
–> angle at which light passes through specimen

–> more accurate measure of specific gravity than reagent strip method which simply changes color

Question 8

what principles affect refractometer

Answer 8

temperature

Question 9

osmolarity

Answer 9

measures concentration of solutes in urine

Question 10

utility of osmolarity testing

Answer 10

measures concentrating ability of kidney

Question 11

basic principles of clinical osmometry

Answer 11

freezing point detects presence of volatile solutes
–> adding 1 osmole decreases freezing point by 1.86