MIDTERM-microscopic exam - urinary sediments - cast and crystals Flashcards
are the only elements found in the urinary sediment that
are unique to the kidney
casts
cast are formed within the ___ and ___, providing
a microscopic view of conditions within the nephron
lumens of the distal convoluted tubules and collecting ducts
Examination of the sediment for the detection of casts is
performed using what power of magnification?
low power
for the analysis of mucus, When the glass
cover-slip method is used, low-power scanning should be performed along the ___ of the cover slip.
edges
The major constituent of casts is ___.
uromodulin
the presence of
urinary casts is termed ___.
cylindruria
The most frequently seen cast is the ___
hyaline type
Whereas the finding of RBCs in the urine indicates bleeding
from an area within the genitourinary tract, the presence of
RBC casts is much more specific, showing bleeding within the
____.
nephron
any damage
to the nephron capillary structure can cause their formation
RBC casts
RBC casts associated with glomerular damage are usually
associated with _- and ___
proteinuria and dysmorphic erythrocytes.
RBC casts are easily detected under low power by their
___ color.
orange-red
They are more fragile than other casts and
may exist as fragments or have a more irregular shape as the
result of tightly packed cells adhering to the protein matrix
rbc casts
They are most frequently
associated with pyelonephritis and are a primary marker for
distinguishing pyelonephritis (upper UTI) from cystitis (lower
UTI).
WBC CASTS
The appearance of WBC casts in the urine signifies __ or ___ within the nephron
infection
or inflammation
wbc casts , they are also present in nonbacterial inflam
mations such as ___ and may accompany
RBC casts in glomerulonephritis.
acute interstitial nephritis
Most frequently,
WBC casts are composed of ___; therefore, they may
appear granular, and, unless disintegration has occurred, mul
tilobed nuclei will be present
neutrophils
Supravital staining
may be necessary to demonstrate the characteristic nuclei
It is particularly helpful for differentiating WBC
casts from ___.
RTE casts
packed casts packed with bacteria can resemble granular casts, CONFIRMATION OF bacterial cats is best made by performing ___ on the dried or cytocentrifuged sediment
gram staining
seen in conjunction with oval fat bodies and
free fat droplets in disorders causing lipiduria.
FATTY CASTS
They are most frequently associated with the nephrotic syndrome, but are
also seen in toxic tubular necrosis, diabetes mellitus, and
crush injuries.
fatty casts
The origin of the granules in nonpathologic conditions
appears to be from the ___ excreted by RTE cells during normal metabolism
lysosomes
Increased cellular
metabolism occurring during periods of strenuous exercise accounts for the transient increase of granular casts that accompany the increased hyaline casts
TRUE OR FALSE
TRUE
TYPE OF MICCROSCOPE THAT CANCONFIRM THE PRESENCE OF A GRANULA CASTS
SCANNING ELECTRON
_ are representative of extreme urine stasis, indicating
chronic renal failure.
Waxy casts
The brittle, highly refractive cast matrix from which these
casts derive their name is believed to be caused by degeneration of the hyaline cast matrix and any cellular elements or
granules contained in the matrix
WAXY CASTS
Waxy casts are more easily visualized than hyaline casts
because of their __
higher refractive index
Often referred to as renal failure casts, broad casts like waxy
casts represent extreme urine stasis.
BROAD CAST
As a result of the brittle
consistency of the cast matrix, they often appear fragmented
with jagged ends and have notches in their sides
waXy casts
As a mold of the distal
convoluted tubules, the presence of broad casts indicates de
struction (widening) of the ___
tubular walls.
All types of casts may occur in the broad form. However,
considering the accompanying urinary stasis, the most commonly seen broad casts are __ and __
granular and waxy
Bile-stained broad, waxy casts are seen as the result of the tubular necrosis caused by __
viral hepatitis
The primary reason for the
identification of urinary crystals is to detect the presence of the
relatively few abnormal types that may represent such disorders as liver disease, inborn errors of metabolism, or renal
damage caused by crystallization of medication compounds within the tubules.
true or false
true
hwo crystals are reported
but Abnormal crystals may be averaged
and reported per __
RFMOMA per hpf; lpf
Crystals are formed by the precipitation of ___, including inorganic salts, organic compounds, and medications
(iatrogenic compounds).
urine solutes
Precipitation is subject to changes
in ___,___,___ which affect
solubility.
temperature, solute concentration, and pH,
Solutes precipitate more readily at low or high temperatures
low
The presence of crystals in freshly voided urine is most frequently associated with __ (high specific gravity) specimens.
In general, organic and iatrogenic compounds crystallize more easily in an __ pH
acidic
inorganic salts are less
soluble in neutral and __ solutions.
alkaline
An exception is ___, which precipitates in both acidic and neutral urine.
calcium
oxalate
. All abnormal
crystals are found in ___ urine.
acidic
Additional aids in crystal identification include the use of __ microscopy and ___ of the crystals.
polarized; solubility characteristics
The geometric shape of a crystal determines its __ and, therefore, its ability to polarize light
birefringence
Just as changes in temperature and pH contribute
to crystal formation, reversal of these changes can cause
crystals to __.
dissolve
___ that
frequently form in refrigerated specimens and obscure sedi
ments may dissolve if the specimen is warmed
Amorphous urates
Amorphous
phosphates require ___ to dissolve, and this is
not practical, as formed elements, such as RBCs, will also be
destroyed.
acetic acid
The most common crystals seen in ACIDIC URINE are urates, consisting of __
amorphous urates
uric acid
acid urates
sodium urates.
uric acid
ph
color
key feature
acid
yellow-brown
rosettes, wedges
Amorphous urates are frequently encountered in
specimens that have been refrigerated and produce a very characteristic __sediment
pink
Colorless (“coffin lids”)
Triple phosphate
Yellow-brown (“thorny
apples”)
Ammonium biurate
Colorless (envelopes,
oval, dumbbell)
Calcium oxalate
3 abnormal crystals for liver disease
leucine
bilirubin
tyrosine
abnormal crystals
yellow (concentric
circles)
tyrosine
