Urine Flashcards
(136 cards)
1
Q
Principal means of waste product excretion in man
A
urination
2
Q
principal constituents of urine (4)
A
water
urea
uric acid
creatinine
3
Q
other urine constituents (5)
A
hormones and their metabolites sodium potassium chloride ammonia
4
Q
functions of the kidney (4)
A
- regulation of water and inorganic ion balance
- removal of metabolic waste products and foreign chemicals from the blood and their excretion in the urine
- secretion of hormones (EPO, Renin, 1,25-Dihydroxyvitamin D)
- Gluconeogenesis
5
Q
Hormone that controls rbc production
A
Erythropoietin
6
Q
Hormone that controls formation of angiotensin
A
Renin
7
Q
Hormone that influences blood pressure and sodium balance
A
Angiotensin
8
Q
Hormone that influences calcium balance
A
1,25-Dihydroxy Vitamin D3
9
Q
Arteriole that carries blood to the nephron
A
afferent arteriole
10
Q
Arteriole that carries blood away from the nephron
A
efferent arteriole
11
Q
Functional unit of the kidney
A
nephron
12
Q
capillary network of the nephron
A
glomerulus
13
Q
blood pressure inside the glomerulus (
A
- is 3x greater than the pressure in other capillaries
- forces the water and small molecules through the capillary membrane and into the Bowman’s capsule.
14
Q
Glomerular filtrate is basically
A
-plasma without the proteins (cells and the large molecular size plasma proteins are unable to pass through the semipermeable membrane)
15
Q
the pH, specific gravity, and osmolality of normal urine =
A
- 7.4
- 1.010
- 285
16
Q
In the average healthy person, >_______ Liters of filtrate are formed each day.
Normal urine output ~_______mLs = only ___% of the amount of filtrate formed; the rest is reabsorbed.
A
180
1500 (1.5 Liters)
1%
17
Q
Course of urine through the nephron
A
afferent arteriole –> glomerulus –> Bowman’s capsule –> PCT (80% of fluid and electrolytes reabsorbed) –> Loop of Henle –> DCT (final reabsorption of sodium, removal of excess acid) –> collecting ducts –> ureters –> bladder
18
Q
Sodium-Potassium pump is under the control of
A
aldosterone (released by the adrenal medulla in response to 1) hypotension or 2) low plasma sodium)
19
Q
Main functions of the nephron at the distal tubule (2)
A
1) final reabsorption of sodium - water/electrolyte balance (=regulated by ADH (secreted by the pituitary)- higher ADH=more water reabsorption, etc..)
2) removal of excess of acid from the body - acid/base balance
20
Q
Descending portion of the Loop of Henle
A
concentrating portion = more permeable to water, water is reabsorbed.
21
Q
Ascending portion of the Loop of Henle
A
= diluting portion - removal of salt with little water lowers salt and osmotic concentration = dilutes the tubular fluid.
-active reabsorption of Na, Cl, Mg, Ca.
22
Q
Diseases of the kidney - 4 main types based on the 4 basic morphologic components initially affected:
A
- glomeruli
- tubules
- interstitium
- blood vessels
23
Q
Glomerular diseases are most often _______________ mediated, but may also result from _________ and __________ disorders.
A
immunologically
metabolic
hereditary
24
Q
Acute inflammation of the glomeruli
A
Acute glomerulonephritis
25
Acute glomerulonephritis may be caused by (4)
- immune complex diseases (=Beta strep A sequelae)
- metabolic/vascular disorders
- toxins
- heredity
26
Symptoms of Acute Glomerulonephritis (8)
| assoc. primarily with _____ casts.
- oliguria, hematuria, proteinuria, decreased GFR, increased BUN and serum creatinine levels, anemia, edema, hypertension
- *RBC casts
27
Nephrotic Syndrome is characterized by
increased glomerular permeability - results in massive proteinuria and excretion of ***fat bodies***
28
causes of Nephrotic Syndrome
- associated with glomerulonephritis
- associated with generalized disease processes (= cancer and lupus)
- associated with circulatory disorders (like those caused by renal vein thrombosis, infections, toxins, preeclampsia, transplant rejection)
29
symptoms of nephrotic syndrome (5)
| (2) may be present
- massive proteinuria (albumin ~ 2-3 g/day) in the absence of depressed GFR, hypoalbuminemia with plasma albumin levels
30
disorders of the kidney most likely due to presence of toxins or infectious agents (2)
tubular and interstitial disorders
31
Renal Tubular Acidosis (RTA) =
| two types =
defective secretion of hydrogen ions by renal tubules in the presence of a normal/nearly normal GFR
- Type I - Distal
- Type II - Proximal
32
Type I / Distal RTA
problem is in the collecting ducts - impaired excretion of hydrogen ions, calcium carbonate is drawn from the bones to act as a buffer.
Results in osteomalacia (bone softening), hypercalcemia, nephrocalcinosis (ppt of ca phos in the tubules resulting in renal insufficiency), and hypokalemia.
-secondary causes = cirrhosis, drugs (ampho B), lithium, kidney transplant rejection, hypergammaglobulinemia.
33
Type II / Proximal RTA
=reduced bicarbonate reabsorption in the proximal tubules, depletes the bicarb content of blood and tissues - results in a more generalized dysfxn that type I RTA.
- will see osteomalacia, but not the nephrocalcinosis and hypokalemia
- secondary causes = mm, transplant rejection, inborn errors of metabolism, drugs and toxins.
34
Type III RTA
combination of I and II
35
Type IV RTA
characterized by mild-moderate insufficiency, hyperchloremic acidosis and hyperkalemia
36
Inherited real diseases characterized by increased urinary excretion of phosphate, glucose, amino acids, low serum phosphorus, systemic acidosis
Fanconi syndrome
37
renal disorder that affects the tubules, interstitium, and renal pelvis
Pyelonephritis
| may be acute or chronic
37
Acute Pyelonephritis:
Definition
Clinical presentation (4)
Lab findings (3)
=Acute bacterial infection of the kidney (ascending/descending)
- Sudden onset with 1) flank pain 2) fever 3) malaise
- Pyuria (many wbcs), bacteria, WBC casts
38
Chronic Pyelonephritis symptoms
pyuria
bacteriuria
development of hypertension
decreased GFR
39
Infection of the bladder =
Cystitis
40
WBC casts in urine
pyelonephritis
41
Passage of kidney stones down the ureter produces _____ _____
and _________.
- Renal colic = sever pain in the back radiating to the groin
- Hematuria
42
Clot formation in the renal veins will result in (2)
- massive proteinuria
| - nephrotic syndrome
43
if stones obstruct the renal pelvis or ureter, ___ may develop
UTI
44
Stones may form (2)
- after recurrent uti with urease-producing organisms (=Proteus)
- when the urine is supersaturated with large quantities of calcium, uric acid, cystine, or xanthine.***Calcium Oxalate = most common constituent of urinary calculi.
45
most common constituent of urinary calculi =
Calcium oxalate
46
Acute renal failure is usually accompanied by
- Oliguria
| - Anuria
47
Renal failure occurring before blood reaches the kidney as in hypovolemia or cardiovascular failure =
Prerenal
48
Renal failure occurring within the kidney
Renal
49
Most common cause of Renal failure =
| Also caused by (2)
Acute tubular necrosis
| Glomerulonephritis and vascular obstruction
50
Renal failure occurring after the urine leaves the kidney and is usually caused by obstruction
Postrenal
51
Stage of chronic renal failure:
| Diminished renal function with normal serum creatinine and BUN levels.
Stage I
52
Stage of chronic renal failure
| Mild renal insufficiency
Stage II
53
Stage of chronic renal failure
| frank renal failure with advancing anemia and acidosis
Stage III
54
Stage of Chronic renal failure
| uremia, manifested as increased BUN and serum creatinine with an acid-base and electrolyte imbalance
Stage IV -
55
Glomerular function is most conveniently measured by the =
Creatinine clearance test on a 24 hr urine specimen
56
Advantages of Creatinine Clearance test (3)
- Amount of creatinine produced endogenously from protein metabolism is relatively constant, and is directly proportional to body SA
- Amount of creatinine in urine is dependent on renal function
- Creatinine is freely filtered at the glomerulus and isn't reabsorbed by the tubules
57
Disadvantages of Creatinine Clearance
-It usually parallels the GFR, but at lower filtration rates it becomes increasingly inacurrate
58
The method of choice to obtain a precise GFR =
Advantages (2)
Disadvantages (2)
=Inulin clearance method
- Glomerular capillary wall is freely permeable to inulin, inulin isn't reabsorbed/secreted/metabolically altered by the renal tubule
- Requires a continuous IV in fusion throughout the duration of the test to maintain a constant plasma level, inulin is technically difficult to measure.
59
The assessment of the concentrating and diluting ability of the renal tubules is accomplished through measuring urine (2)
specific gravity and osmolality
60
The ratio of the mass of a solution compared with the mass of an equal volume of pure water =
specific gravity
61
the number of dissolved particles in a solution is determined by
osmolality
62
Secretory function of the renal tubules is evaluated by
injecting exogenous organic anions/cations into the circulation and determining their clearance values.
- Paraaminohippruate (PAH) (organic anion) - normally used.
- normal PAH clearance = 600-700 mL/min
63
24 hour urine for protein and creatinine
protein or creatinine result X 24hr urine volume (ml/min) / 100
64
Least invasive specimen acceptable for urine culture =
midstream urine collection
65
Physical characteristics of urine for routine UA (4)
- color
- appearance
- specific gravity
- volume and/or odor
66
chief pigment of urine =
| other pigments in lesser concentration = (2)
urochrome
| -uroerythrin and urobilin
67
Specific gravity <1.007 is termed what and is caused by
=hyposthenuric
| -Excessive fluids/diuretics, DI, renal disease where conc. ability is lost.
68
Specific gravity fixed @ 1.010 =
Isosthenuric
| -Chronic renal disease where conc. and diluting ability lost --- SG = same as glomerular filtrate.
69
Specific Gravity > 1.020 =
Hypersthenuric
| -proteinuria, glycosuria, dehydration, radiographic dyes
70
Urinometer must be corrected for presence of glucose and protein by
For every gram/dL of protein or glucose, subtract .003 from the urinometer value.
71
Urine test strip method
contains a pretreated electrolyte that elicits a pH change.
This method is based on the ionic concentration of urine
-not affected by glucose, protein or ***radiographic dyes***
72
Refractometer method
=based on the principle of the refractive index
- as # of diss. particles in soln. increases, so does the refractive index.
- its corrected for temperature from 15 to 37 degrees
73
Odor:
Ammonia =
Sweet, fruity =
Maple syrup =
- can indicate bacterial growth
- can indicate the presence of ketones
- can indicate MSUD (aminoacidopathy)
74
Volume:
Anuria =
Oliguria =
Polyuria =
- absence of urine - acute renal failure, urinary tract obstruction, major transfusion reaction (free Hgb clogs tubules)
- <500 ml/day - poor blood supply (shock/dehydration), fluid shift (edema), urinary tract obstruction, poor kidney function (acute/end stage)
- > 2000 ml/day - increased fluid intake, DM/DI, renal disease affecting concentrating ability
75
Dysuria =
any increase in urine volume
76
pH of urine reflects the ability of the kidney to maintain normal __ concentration in ______ and _____________ _____.
H+
plasma
extracellular fluid
77
Average pH of urine =
6
78
pH methodology
urine test strip contains indicators methyl red and bromthymol blue - gives a range of color change from orange - green - blue as pH rises.
79
Sources of error for urine pH
- Runover phenomenon = too much urine on dipstick/ urine allowed to stand too long before testing = falsely elevated pH = alkaline
- Acid urine = starvation diets, proteinuria, diarrhea, DM
- Alkaline = RTA, renal failure, UTI, vomiting, diet high in fruits/veggies
80
Leukocyte esterase - purpose
| methodology
= detects the presence of pyuria (wbcs in urine)
-Neutrophils contain esterases, catalyze the production of indoxyl from an indoxyl carbonic acid ester. The indoxyl reacts with diazonium to produce a purple color.
81
Leukocyte Esterase - sources of error
false + = with formaldehyde and oxidizing agents
| false - = high protein, glucose, SG, high doses of cephalexin, gentamycin, ascorbic acid.
82
Nitrite - used to detect the presence of certain ________ in urine
methodology =
bacteria
- based on the Griess test; test strip depends on reduction of nitrates to nitrites by enzymatic action of certain bacteria.
- in acid pH, nitrite reacts with aromatic amine to produce a pink color
83
Nitrite - sources of error
false + = bacterial contamination of improperly collected or stored specimen
false - = high ascorbic acid, extremely high bacterial count, antibiotic therapy, UTI caused by non nitrite-reducing bacteria, urine not in bladder for > 4hrs
84
majority of ketone composition =
B-hydroxybutyric acid
85
Presence of ketones in the urine is due to
=the incomplete metabolism of fats for energy
86
Ketones - methodology
reagent strip test is based on modified tube test
-detects acetoacetic acid and acetone - they react with sodium nitroprusside and glycine in alkaline medium to produce a purple colorj
87
Ketones- sources of error
falsely decreased - early stages of DKA - beta levels are increased but acetoacetate is still normal - blood gases and glucose levels are more useful in this case
false + = large doses of levodopa
false - = improperly stored specimen (=conversion of acetoacetic acid to acetone with subsequent evaporation)
88
Glucose is present in urine only when plasma glucose levels
exceed the renal threshold (160-180 mg/dL)
89
Glucose - methodology
Test strip is based on the glucose-oxidase/peroxidase reaction = specific for glucose
- Gluc reacts with glucose oxidase to form gluconic acid and H2O2 - H2O2 reacts with peroxidase to oxidize the chromogen / indicator which produces color
- -Ortho-toluidine =blue, iodine = brown, tetramethylbenzidine = green
90
Glucose - sources of error
false + = strong oxidizing agents
| false - = levodopa metabolites and ascorbic acid, increased ketones, too cold due to refrigeration.
91
Methodology for reducing substances
Copper reduction tests - will react with sufficient quantities of any reducing substance in the urine (lactose, fructose, galactose, maltose, pentoses)(found in the urine of people with inherited metabolic disorders) - if that is suspected ,sugar can by identified using thin layer chromatography
92
Clinitest - sources of error
false + = HGA, drugs and their metabolites (ascorbic acid/salicylates), preservatives (formalin)
false - = if clinitest tube is mixed before 15 seconds, presence of radiographic contrast media
Passthrough rxn = high levels, starts positive, then passes through all colors, then ends on greenish brown which corresponds with a lower concentration than orange - should be reported as > 4+
93
Test for Lactose
Rubner's qualitative test - uses lead acetate, forms a brick red solution, then a red ppt with a clear supernatant
Glucose = yellow ppt with yellow soln.
94
Test for Fructose
Resorcinol + acidified urine, fructose will cause formation of a heavy red ppt = soluble in ETOH - urine must be fresh when testing (will form glucose in alkaline urine)
95
Test for deficiency in galactose 1-Phosphate uridyl transferase in
newborns
test is based on measuring transferase activity in red cells - wb is added to rxn mixture, which fluoresces if enzyme is present
96
Test for Pentose
Bial-orcinol test - pentose produces olive green compound (soluble in amyl alcohol)
97
Pentose is found in urine (2)
- after ingestion of large amounts of fruit
| - in idiopathic pentosuria
98
Test for Sucrose
detected in thin layer chromatography, but stained by a substance no dependent on reducing properties.
99
presence of porphyrins in urine =
red wine color
100
presence of melanin/melanogen =
urine darkens on standing and reacts with nitroprusside and ferric chloride
101
Of the normal protein excreted, 1/3 = ____ _________ glycoprotein, 1/3 = _______, and the rest is small globulins
```
Tamm Horsfall (=uromodulin)
albumin
```
102
Protein - methodology
Reagent strip = sensitive only to Albumin
| -based on the principle of protein-error of pH indicators
103
Protein - sources of error
false + = alkaline urines, excessive wetting of test strip, presence of ammonium compounds used to clean the skin
false - = proteins other than albumin are present
104
Protein - confirmatory tests
= semi-quantitative method
- sulfosalicylic acid test
- heat and acetic acid test
105
Bence Jones proteinuria associated with (3)
multiple myeloma
macroglobulinemia
malignant lymphomas
106
as larger proteins appear, the prognosis
worsens
107
tubular disease is associated with the loss of
very small proteins
108
glomerular disease allows escape of
intermediate sized protein molecules
109
Heavy proteinuria
=3-4 G/day - nephrotic syndrome
110
Moderate proteinuria
1-3 g/day - glomerular diseases and multiple myeloma
111
Minimal proteinuria
<1 G/day - chronic pyelonephritis, ~inactive Glomerular disease, tubular disease, postrenal proteinuria
112
presence of abnormal rbcs in urine
hematuria
113
presence of free hgb in urine
hemoglobinuria
114
myoglobinuria
acute destruction of muscle fibers = rhabdomyolysis
- if large amounts are present, anuria may result
- seen in skeletal muscle diseases, trauma, infections, influenza, herpes, EBV, Legionella, toxic substances, a variety of congenital disorders
115
Blood - methodology
based on the liberation of O2 from peroxide in the test strip by the ***peroxidase-like activity of heme***
116
Blood- Sources of Error
false - = really high nitrite/ really high ascorbic acid, falsely decreased due to poor mixture of specimen prior to testing.
false + = oxidizing contaminants or microbial peroxidse
117
Test for bilirubin detects what form of bilirubin?
Conjugated (water-soluble)
118
Bilirubin - methodology
test strip is based on the diazo reaction = utilizes coupling reaction of a diazonium salt with bilirubin in an acid medium to produce a red violet azo dye.
-Both neg results on suspicious urines and pos results on test strip should be confirmed using Ictotest (=uses same rxn)
119
Bilirubin - Sources of Error
false - = large amounts of ascorbic acid, prolonged specimen storage (bilirubin broken down by light exposure)
false + = drugs
120
Substance formed in the intestine by the bacterial breakdown of conjugated bilirubin
urobilinogen
121
Urobilinogen - methodology
based on Ehrlish aldehyde reaction - based on the formation of a red azo dye from the coupling of urobilinogen with a diazonium compound in an acid medium
122
Urobilinogen - Sources of Error
False - = formalin or prolonged standing
| False + = drugs
123
Increased urobilinogen
| normal bilirubin
Hemolytic Jaundice
124
Increased urobilinogen and bilirubin
Hepatocellular Jaundice
125
Decreased Urobilinogen
| Increased Bilirubin
Obstructive Jaundice
126
presence of Indican in urine ~ with
| color =
small bowel bacterial contamination and GI abnormalities
| green-blue
127
Excess of one or more amino acids in the urine
Aminoaciduria
- overflow (4)
- transport (2)
128
Overflow Aminoacidurias (4)
Phenylketonuria - phenylalanine hydroxylase deficiency - Guthrie test
- Alkaptonuria - Homogentisic acid oxidase deficiency (=accum. of HGA) - causes urine to turn brown-black upon standing - accumulates in cartilage tissue.
- MSUD - Elevated Leu, Ile, Val and excretion of their corresponding ketoacids.
- Tyrosinosis = fumarylacetoacetate deficiency = kidney damage leads to Fanconi's with VD-resistant ricketts -Tyr and Leu crystals present
129
Renal Transport Aminoaciduria (RTA)-C
- Cystinuria - one renal tubular abs mechanism for lysine, arginine, ornithine, cystine - cystine = only one that crystallizes
- ---cyanide nitroprusside test = +
- Fanconi Syndrome
130
Lipiduria is most often seen in _________ ________
| Oval Fat Bodies =
nephrotic syndrome
| RT cells / macrophages in which globules of fat have accumulated.
131
Urine containing lymph =
chyluria
132
Clinical manifestation of chyluria
+ protein, wbcs and rbcs present, milky/opalescent urine
133
screening test for porphyrins =
| confirmatory test for porphyrins =
- Watson-Schwartz test = uses Ehrlich's reagent
| - Hoesch test
134
Increased plasma calcium ~ with
HyperPTH and vice versa
135
Two methods of measuring calcium =
EDTA titration
Sulkowitch test
-Ca++ is ppt'd out as Calcium Oxalate - degree of ppt is noted visually.
