Micro UA part 2 Flashcards
Casts
where are they formed?
shape?
formed only in the kidney nephron
loop of henely
distal tube
collecting duct
Shape represents tubule
Structure of casts
parallel sides
rounded edges
some fragmented
Composition of casts
tamm-horsfall (uromodulin)
glycoprotein excreted by RTE - lubrication
constant rate
makes up mucus
‘gels’
not detected by rgnt strip
Formation of casts
tam-horsfall RTE protein
fibrils from network loose
futher matrix
urine comp attaches to matrix
cast detaches from RTE
What is casts in urine called
cylinduria
occurs more readily if urine flow decreased
pH is acidic
increased electrolytes
T/F forms of casts dont block the urine in the nephron
false
patho vs non patho casts
patho: renal issue
non patho: dehydration
Types of casts
elements/size/shape/time
hyaline - most common
Cellular - Rbc/wbc/rte
fatty
granular
broad - collecting duct
waxy - severe renal stasis
Hyaline cast
most frequent
in loop of henely/distal/collecting
0-2 norm
low power
Noth path: excersise/dehydration/heat
Patho: acute glomer, pylnoneph, renal
What do hyaline casts look like when they come from the henely loop?
wiggly tails
Hyaline cast morphology
hard to see
sternheimer-malbin/phase contrast
parallel with round edges
few granules
cells will stick
RBC casts
rbc embedded in matrix
not stuck on outside
free floating rbcs seen
“pos” on blood strip
Non path: rare - extreme exersice
Path: bleeding in nephron assoc w glomerulon
If hgburia is present, what color is the rbc cast?
methgb?
orange/red color
methgb is brown/red
What are hgb type casts associated with?
associated with aute tubular necrosis
very large amounts toxic to kidneys and result in renal failure
WBC casts
wbc embedded in matrix
neutrophils
granular appearance, dont confuse w wbc clumps
Path: infections/inflamm
Pylonephritis
upper uti
Cystitis
lower uti doesnt produce wbc casts
Bacteria casts
bacteria in cast
associated with pylonephritis
wbc and free floating bacteria present
confused w granular casts
RARE
confirm with gram stain
RTE casts
very serious very rare
tubular destruction
diff from wbc casts use STAINING mononuclear structure
Oval fat body casts
comp. of fat drop of oval fat body
refractile
confirm with polarized light and fat stain
Sudan III or Oil Red O
Cholesterols - maltese cross
mixed cell
diff cell types
rbc/wbc: glomerul
wbc/RTE: plyonephritis
Granular casts
pick up material from urine - degrade “granularity”
crystalize
rbc
wbc
CELLULAR MATERIAL FROM RTE MOST COMMON
Granular casts start as
start as course and go to fine
must have urinary stasis occur for granular casts to form
Waxy cast
long term urinary stasis
chronic renal failure
seen with other casts
occur from futher breakdown of gran. casts
brittle refract index
fiber
fragmented square endds
notches
dark pink
