Lecture 1/19

• Crenated RBC's indicate the urine is old
• A lysing agent (e.g. acetic acid) can be used to differentiate yeast from RBCs
• Squamous epithelial cells are the most common sediment seen in urine; normal; sloughed from urethra
• Tranisitional epithelium is from inside of bladder; occasional is okay
• Clue cells are seen in patients that have Gardnerella vaginalis
• calcium oxalate crystals are the most common crystals seen in urine; if they stick together, they form kidney stones
• the shape of a calcium oxalate crystal depends on the amount of water in the crystal
• oval calcium oxalate crystals tend to be in acidic/neutral urine
• ammonium biurate appears in alkaline urin
• triple phosphate crystals are only present in alkaline urine
• hyaline casts are cylindrical protein structures made of the same proteins that make up mucous
• granular casts are formed in the tubules of nephrons; if WBC's, RBC's, epis present, end up in casts; as casts go through nephrons, cells disintigrates and shows up in casts
• the presence of casts and their granularity indicates that the urine is moving slowly
• in coarse granular casts, the casts are larger
• In a fatty cast, the lipids will refract light; look iridescent
• waxy casts are not as translucent as hyaline casts
• waxy casts - water has been sucked out; more rigid; means urine is moving through tubules very slowly
• waxy casts will have cracks and splintered ends
• oval fat bodies are renal tubules with fat droplets
• mucous in urines indicates irritated nephrons
• trichomonas vaginalis is a sexually transmitted parasite; must be moving in order to ID
• T vaginalis - see 6-8 flagella and central undulating membrane moving in darting fashion
• sulfa drug crystals are usually clinically insignificant