352 



PHYSIOLOGICAL CHEMISTRY. 



Epithelial Cells. The detection of a certain number of these 

 cells in urinary sediment is not, of itself, a pathological sign, since 

 they occur in normal urine. However, in certain pathological con- 

 ditions they are greatly increased in number, and since different 

 areas of the urinary tract are lined with different forms of epithelial 

 cells, it becomes necessary, when examining urinary sediments, to 

 note not only the relative number of such cells, but at the same time 

 to carefully observe the shape of the various individuals in order 

 to determine, as far as possible, from what portion of the tract they 

 have been derived. Since the different layers of the epithelial lin- 

 ing are composed of cells different in form from those of the as- 

 sociated layers, it is evident that a careful microscopical examina- 

 tion of these cells may tell us the particular layer which is being 

 desquamated. It is frequently a most difficult undertaking, how- 

 ever, to make a clear differentiation between the various forms of 

 epithelial cells present in a sediment. If skilfully done, such a 

 microscopical differentiation may prove to be of very great diag- 

 nostic aid. 



The principal forms of epithelial cells met with in urinary sedi- 

 ments are shown in Fig. 105, below. 



FIG. 105. 





EPITHELIUM FROM DIFFERENT AREAS OF THE URINARY TRACT. 



a, Leucocyte (for comparison) ; b, renal cells ; c, superficial pelvic cells ; d, deep 

 pelvic cells ; e, cells from calices ; f, cells from ureter ; g, g, g, g, g, squamous epi- 

 thelium from the bladder; h, h, neck-of-bladder cells; i, epithelium from prostatic 

 urethra ; k, urethral cells ; /, /, scaly epithelium ; m, m' , cells from seminal passages ; 

 n, compound granule cells ; o, fatty renal cell. (Ogden.) 



