ORGANIZED SEDIMENTS. 181 



ORGANIZED SEDIMENTS. 



1. Epithelium. Epithelium occurs in urine as isolated cells; or, 

 occasionally, groups of attached cells may be demonstrated. In 

 normal urine there is always a limited number of epithelial cells 

 due to ordinary desquamation, but under pathological conditions 

 the number becomes greatly increased. This may be due to inflam- 

 mation, suppuration, friction, and the action of bacteria. The 

 elements from the renal tubules are generally small round cells, 

 columnar or cuboidal cells ; those from the excretory duct are of the 

 tall columnar variety ; and those from the pelvis, ureter, and blad- 

 der are of the transitional type, exhibiting irregular forms spindle- 

 shaped, polyhedral, and large round cells, some having more than 

 one nucleus, and some exhibiting pointed processes ; cells from the 

 prostatic portion of the urethra are of the squamous type, while 

 those from the free portion are low columnar cells. In the female, 

 squamous epithelium lines the entire urethra. 



2. Blood (Fig. 10). Blood occurs only in pathological urine; 

 it may be detected microscopically by the presence of the red disks. 

 These are known by their form and the absence of nuclei ; they sel- 

 dom form in rouleaux, but often exhibit crenation. Tuberculosis 

 of the kidneys, pyelitis, cystitis, and other affections are suggested 

 by the presence of blood. 



3. PUB (Figs. 9 and 14). Pus consists of dead or dying leuco- 

 cytes, which have escaped from the vascular channels. Leucocytes 

 are concerned in repairing diseased tissues and the destruction of 

 microbes. \ 7 ast numbers die in the conflict, and these constitute 

 pus. Pus cells may be distinguished from other elements by their 

 size, granular appearance, and nuclei. They often contain several 

 nuclei in each cell and occasionally exhibit amoeboid movement. 

 Pus is invariably present in cystitis, gonorrhcea, tuberculosis, etc. 



4. Casts. These originate in the renal tubules and comprise 

 several varieties : Blood casts, epithelial casts, granular casts, fatty 

 casts, and hyaline casts. 



Blood casts (Fig. 13) are the result of hemorrhage in the urinary 

 tubules, and indicate such infections as haematuria, renal congestion, 

 and acute nephritis. 



