AUBF Flashcards
(152 cards)
1
Q
What is urine?
A
A liquid tissue biopsy of the urinary tract containing waste products excreted by the kidneys
2
Q
What percentage of urine is composed of water?
A
Approximately 95%
3
Q
What is the major inorganic component of urine?
A
Chloride
4
Q
List other inorganic components of urine.
A
- Sodium
- Potassium
- Sulfate
- Phosphate
- Ammonium
- Magnesium
- Calcium
5
Q
What is the major organic component of urine?
A
Urea
6
Q
List other organic components found in urine.
A
- Creatinine
- Uric acid
- Hippuric acid
7
Q
What is the normal daily urine excretion volume?
A
Approximately 0.6-2 liters (or 0.5-1.8L)
8
Q
What does polyuria refer to?
A
Increased urine output
9
Q
What does oliguria refer to?
A
Decreased urine output
10
Q
What does anuria refer to?
A
Complete cessation of urine flow
11
Q
What does dysuria refer to?
A
Painful urination
12
Q
What does nocturia refer to?
A
Increased excretion of urine at night
13
Q
What is the normal day to night urine ratio?
A
2:1 to 3:1
14
Q
Describe the appearance of normal urine.
A
Clear, with color ranging from straw (pale yellow) to amber
15
Q
What causes the yellow color of urine?
A
Presence of the pigment urochrome
16
Q
When is urochrome excretion increased?
A
During fever, thyrotoxicosis, and starvation
17
Q
What pigment can cause pink coloration in urine?
A
Uroerythrin
18
Q
What is urobilinogen?
A
An oxidation product of the normal urinary constituent that imparts an orange-brown color to non-fresh urine
19
Q
What does urine color indicate?
A
Hydration level and urine concentration
20
Q
What color of urine is associated with lead porphyrinuria?
A
Yellow
21
Q
What causes red-orange urine in patients undergoing tuberculosis treatment?
A
Intake of Rifampin
22
Q
What color is associated with very dilute urine?
A
Colorless
23
Q
What could cause very dilute urine?
A
Recent fluid consumption, polyuria (DI or DM)
24
Q
What is indicated by a concentrated urine specimen?
A
Excess urobilin
25
What substances can lead to yellow-orange urine?
* Bilirubin
* Acriflavine
* Phenazopyridine (Pyridium)
26
What causes green or blue-green urine?
Bilirubin oxidized to biliverdin
27
What infections can cause colored urine?
Pseudomonas infection
28
What substances can lead to reddish urine?
* RBCs
* Hemoglobin
* Myoglobin
* Porphyrins
* Beets
* Rifampin
* Menstrual contamination
* Fuscin
* Aniline dye
29
What might cause brown or black urine?
* Methemoglobin
* Homogentisic acid
* Melanin or melanogen
* Phenol derivatives
* Argyrols
* Methyldopa or Levodopa
* Metronidazole
30
What is the recommended time frame for testing urine specimens after collection?
Within 2 hours
31
What happens to the color of unpreserved urine?
Darkened
## Footnote
Due to modified oxidation or reduction of metabolites.
32
How does the clarity of unpreserved urine change?
Decreased
## Footnote
This is often due to bacterial growth and precipitation of amorphous material.
33
What is the change in odor of unpreserved urine?
Increased
## Footnote
Caused by bacterial multiplication and breakdown of urea into ammonia.
34
What is the typical change in pH for unpreserved urine?
Increased
## Footnote
Resulting from the breakdown of urea into ammonia by urease-producing bacteria.
35
What happens to glucose levels in unpreserved urine?
Decreased
## Footnote
Due to conversion to acids and alcohols by bacteria and yeast.
36
What is the change in ketones in unpreserved urine?
Decreased
## Footnote
Caused by glycolysis and bacterial usage.
37
How does bilirubin change in unpreserved urine?
Decreased
## Footnote
Due to decreased exposure to light and photo-oxidation to biliverdin.
38
What happens to urobilinogen levels in unpreserved urine?
Decreased
## Footnote
Resulting from volatilization and bacterial metabolism.
39
What is the change in nitrite levels in unpreserved urine?
Increased
## Footnote
Multiplication of nitrate-reducing bacteria leads to this increase.
40
What is the effect on RBCs, WBCs, and casts in unpreserved urine?
Positive
## Footnote
This indicates disintegration in dilute and alkaline urine.
41
What happens to trichomonas if unpreserved for a longer period?
Decreased
## Footnote
Loss of motility and death occur over time.
42
What is the effect of bacterial growth on urine clarity?
Decreased
## Footnote
Caused by the precipitation of amorphous material.
43
Fill in the blank: The _______ of unpreserved urine increases due to bacterial breakdown of urea.
pH
44
True or False: The odor of unpreserved urine typically decreases.
False
## Footnote
The odor increases due to ammonia production.
45
What is the normal range for renal plasma flow in ml/min?
600-700 ml/min
46
What is the renal blood flow rate for a normal adult in L/min?
1.2 L/min
47
What percentage of cardiac output do the kidneys receive?
Approximately 20-25%
48
What are the three mechanisms involved in urine formation?
1. Renal blood flow
2. Glomerular filtration
3. Tubular reabsorption & secretion
49
What is the functional unit of the kidney?
Nephrons
50
Which components make up the renal/excretory system?
* Kidneys
* Ureters
* Urinary bladder
* Urethra
51
What are the arterioles formed from the renal artery that carry blood towards the nephrons called?
Afferent arterioles
52
What is the filtering apparatus of the nephrons known as?
Glomerulus
53
What is the pH of urine formation in the nephrons?
7.4
54
What is the osmolality of urine compared to plasma?
Similar to plasma
55
Which parts of the renal tubules are responsible for concentrating and diluting urine?
PCT, LH, DCT, and CD
56
Where does the majority of reabsorption (65-80%) occur in the nephron?
Proximal Convoluted Tubule (PCT)
57
What substances are primarily reabsorbed in the Proximal Convoluted Tubule (PCT)?
* Water
* Amino acids
* Glucose
* Electrolytes
58
What is the role of Antidiuretic Hormone (ADH) in the nephron?
Promotes water reabsorption
59
Which part of the nephron is permeable to water but impermeable to salt?
Descending Limb of the Loop of Henle (DLH)
60
Which part of the nephron is permeable to salt but impermeable to water?
Ascending Limb of the Loop of Henle (ALH)
61
Fill in the blank: The renal tubules include the ______, Loop of Henle, Distal Convoluted Tubule, and Collecting Duct.
Proximal Convoluted Tubule (PCT)
62
What is the mechanism of the Loop of Henle?
Countercurrent mechanism
63
True or False: The Distal Convoluted Tubule (DCT) is primarily involved in reabsorbing glucose.
False
64
What is the term for the fluid that is filtered through the glomerulus?
Filtrate
65
What are the primary wastes removed from the body during urine formation?
* Nitrogenous wastes
* Toxins
66
Fill in the blank: The _______ is the part of the nephron that aids in the reabsorption of electrolytes.
Distal Convoluted Tubule (DCT)
67
What size of particles are allowed to pass through the glomerulus?
<70 kilo daltons
68
Fill in the blank: The glomerulus is _______-charged.
Negatively
69
In which part of the nephron does casts form?
DCT & Collecting Duct
70
How are protein charges described?
Amphoteric; can be positive or negative
71
How does blood pH affect the protein charge?
Low pH = positive
High pH = negative
72
True or false: Protein charge is normally negative
True
73
What is the Urea Clearance Test used for?
It is a test that was used to assess glomerular filtration but is no longer used due to dietary effects and 40% reabsorption in tubules.
## Footnote
Urea clearance is affected by protein intake and other dietary factors.
74
What is the gold standard for assessing glomerular filtration rate (GFR)?
Inulin Clearance Test
## Footnote
The Inulin Clearance Test measures a substance filtered by the glomerulus that is neither reabsorbed nor secreted by the tubules.
75
What substance is used in the Inulin Clearance Test?
Inulin, a polymer of fructose.
## Footnote
Inulin is an exogenous substance that helps measure GFR effectively.
76
Which clearance test is most commonly used to assess GFR?
Creatinine Clearance Test
## Footnote
Creatinine clearance is favored due to the almost complete filtration and lack of reabsorption of creatinine.
77
What type of specimen is needed for the Creatinine Clearance Test?
24-hour urine and serum/plasma.
## Footnote
This dual specimen collection allows for accurate GFR assessment.
78
How is Creatinine Clearance calculated?
Using the formula: urine creatinine x urine volume in mL per min / plasma creatinine.
## Footnote
This formula provides a measure of kidney function based on creatinine levels.
79
What is the urine volume collected over 24 hours in the sample provided?
2,880 mL
## Footnote
This volume is necessary for calculating creatinine clearance.
80
Fill in the blank: The _______ Clearance Test is no longer used because it is affected by diet.
Urea
## Footnote
Urea clearance is influenced by dietary protein intake.
81
True or False: Almost 100% of creatinine is reabsorbed by the kidneys.
False
## Footnote
Almost 100% of creatinine passes through the glomerulus and is not reabsorbed.
82
Greatest source of error in renal function test
Improperly collected urine specimen
83
What colligative properties increaes when the osmolality of urine increases?
* Boiling point
* Osmotic pressure
84
Tests that assess tubular reabsorption
Fishberg Concentration test
Mosenthal Test
Specific Gravity
Osmolality/osmolarity
85
Normal value of urine SG
1.002–1.035
86
Osmolality formula
Osm=1.86Na + (Glu/18) + (BUN/2.8) + 9
Or
Osm=2Na + (Glu/20) + (BUN/3) + 9
87
What is the principal contributor of osmolality?
Sodium (Na)
88
Normal pH value of urine
4.5–8.0
89
What is the principle of pH in the reagent strip method? What is/are the reagent/s?
Double indicator system using methyl red and bromthymol blue
90
What is the confirmatory test for protein in the urine?
3% Sulfosalicylic acid
91
What is the sensitivity range of the reagent strip method of glucose?
75-125 mg/dL
92
What does the copper reduction test detect?
All reducing sugars
93
Which reagent strip parameter uses sodium nitroprusside as he reagent?
Ketones
94
How does lactose affect the acetest tablet test for ketones?
It enhances the color differentiation
95
Ketones may be positive in patients that have:
DM, Vomiting, & Starvation
96
What type of ketone do we have in the body?
B-hydroxybutyric acid
97
This ketone consists 20% in the body
Acetoacetic acid
98
Modified true or false: Sodium nitroprusside can only detect acetone used in the urine reagent strip
False; detects acetoacetic acid
99
Which parameter in the reagent strip method uses tetramethyl benzidine?
Blood
100
Speckled pattern in the blood pad indicates __________.
hematuria
101
Ehrlich reaction uses what reagent for detecting urobilinogen?
para-dimethyl aminobenzaldehyde
102
Which test for bilirubin is more sensitive?
Ictotest tablet
103
Which parameter of the reagent strip method is considered as a screening for UTI?
Nitrite
104
Nitrite is based on what principle?
Greiss reaction
105
What are the possible causes for a negative nitrite infection, despite the patient having a bacterial infection?
Non-reductase bacteria present
Insufficient contact time between bacteria and nitrite
large quantitites of bacteria
Presence of antibiotics
106
Which parameter in the reagent strip method has the longest reading time?
Leukocyte esterase
107
What is the principle of detecting the Specific gravity of a urine sample?
Change in the pKa of a polyelectrolyte
108
RBCs in hypotonic urine are known as ______.
Ghost cells
109
Dysmorphic RBCs in the urine may indicate what?
Glomerular damage
110
What is the predominant WBC in the urine?
Neutrophil
111
In a hypotonic urine, WBCs are called ________ because of what?
Glitter cells; it shows false motility (Brownian movement)
112
What stain is used in detecting eosinophils in the urine?
Hansel stain
113
What disease is associated with the appearance of eosinophils in the urine?
Drug-induced interstitial nephritis
114
What is indicative of vaginal infection caused by Gardnerella vaginalis?
Clue cells
115
What type of epithelial cell is considered to be the most clinically significant?
Renal Tubular Epithelial Cells
116
Lipid-containing RTE cells are most often found in patients with _______.
Nephrotic syndrome
117
What is added on to the urine to differetiate yeasts from RBCs?
2-5% Acetic acid
118
Mucus threads are usually made up of what?
Tamm-Horsfall Protein
119
Casts are formed in _____ and _____.
Distal Convoluted Tubule (DCT) & Collecting Ducts (CD)
120
What is the difference between casts and cylindroids?
Casts: formed in the DCT & CD; uniform in shape
Cylindroids: formed in the ALH & DCT; tapered end
121
What cast is considered normal when found in low numbers in the urine?
Hyaline cast
122
What casts is considered normal when found in low numbers in the urine?
Hyaline cast
123
The appearance of _______ can distinguish cystits from pyelonephritis.
WBC Cast
124
What is considered ass the renal failure cast?
Broad cast
125
Which cast is the final degenerative form of all casts?
Waxy cast
126
75% of renal calculi found in the urine are ________.
Calcium Oxalate (CaOX)
127
Opposite pH agents added in the urine would ______ crystals.
dissolve
128
What are the other names of triple phosphate crystal?
Struvite; Ammonium Magnesium Phosphate; Coffin-lid crystal
129
What are the crystals found in liver diseases?
Bilirubin, Leucine, & Tyrosine crystals
130
This crystal may be confused with a parasitic ova
Leucine crystal
131
Cystine crystals are often found in patients with ________ syndrome.
Fanconi
132
Cystine crystals are sometimes mistaken as _______.
Uric acid crystal
133
Described as fine colorless to yellow needles the frequently form clumps or rosettes.
Tyrosine crystals
134
Also known as staircase crystals
Cholesterol crystals
135
Crystal found in patients with nephrotic syndrome
Cholesterol crystals
136
Plate-shaped crystals found in patients with history of taking meglumine diatrizoate
Radiographic contrast media crystals
137
What is the primary cause of the appearance of sulfonamide crystals?
inadequate patient hydration
138
Crystal that forms bundles when refrigerated, and is found in an acidic urine.
Ampicillin crystal
139
The cerebrospinal fluid is found in ______.
Subarachnoid space
140
What are the functions of the CSF?
* Supplies nutrients to the nervous tissue
* Remove metabolic wastes
* Acts as a cusion for the brain and the spinal cord
141
Modified true or false: The CSF is an ultrafiltrate of the blood.
False; not an ultrafiltrate
142
What is the normal CSF volume for adults and neonates?
Adults: 90-150 mL
Neonates: 10-60 mL
143
Modified true or false: 20mL of CSF is produced by the body every hour
True
144
70% of the CSF is produced in the __________.
Choroid plexuses
145
If CSF is constantly produced, how doesn't it build-up inside the body?
It drains via the arachnoid granulations or villi
146
The position of the patient during the collection of CSF
Fetal position
147
During the lumbar puncture, CSF is collected in which part of the body?
Between the 3rd and 4th or 4th and 5th lumbar vertebrae
148
When 3 tubes are successfully collected during the spinal tap, what is the proper order in submitting the tubes?
Tube 1: Clinical Chemistry and Serology
Tube 2: Microbiology
Tube 3: Hematology
149
If only a single tube is collected for CSF, what is the order of draw?
Microbiology -> Hematology -> CC & Serology
150
High opening pressure during the collection of CSF are seen in patients with _________.
meningitis
151
Modified true or false: Organisms that causes meningitis are not always encapsulated such as the N. gonorrhoeae
False; always encapsulated
152
Why is the CSF sample for hematology refrigerated for storage?
To preserve cells
