Urine Sediments: Cells and Crystals II Flashcards Preview

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Flashcards in Urine Sediments: Cells and Crystals II Deck (10):

Composition of casts

fibrous protein network of uromodulin (any cells can get caught)


Formation of casts

Cells of the ascending loop of hence continuously secrete uromodulin and as the urine becomes increasingly concentrated in the distal convoluted tubules and collecting ducts, uromodulin forms fibrils that attach it to the lumen cells.


Another name for Tamm-Horsfall glycoprotein



Factors that promote formation of casts

Urinary stasis
Acidic pH
High specific gravity
Increased plasma proteins (such as albumin) in the ultrafiltrat


Kidney Pathology and casts formation

Distal tubules and collection ducts are the sites of most formation because the SG is highest and the pH is lowest


Factors that increase the rate of cast degradation

alkaline urine
low SG<1.003


Stages of cellular degeneration in a cast

1. Hyaline Casts
2. Cellular Cast
3. Mixed Granular Cast
4. Coarsely Granular Cast
5. Finely Granular Casts
6. Waxy Cast


significance of mucous

No significance, may be increased in inflammation irritation


significance of bacteria with particular attention paid clue cells

frequently contaminant of skin or vagina, in combo with excess WBCs source is likely bacterial vaginosis


significance of yeast/fungi

may be vaginal contaminant, candida albicans and candida glabrata are the most common species found, more common in immunocomp patients and diabetes mellitus patients