CILIATED EPITHELIUM. 



Ciliated epithelium is found throughout the whole extent of the 

 air-passages and their prolongations (but not in the part of the nostrils 

 supplied by the olfactory nerves, nor in 

 the lower part of the pharynx); in the 

 Fallopian tubes and the greater part of 

 the uterus ; in some of the efferent ducts 

 of the testicle (where the cilia are longer 

 than elsewhere in the body); in the ven- 

 tricles of the brain, and the central canal 

 of the spinal cord; and, according to 

 some authorities, in the convoluted tubules 

 of the kidney. 



Transitional epithelium is a stratified 

 epithelium consisting of only two or 

 three layers of cells. It occurs in the 

 urinary bladder, the ureter, and the 

 pelvis of the kidney. The superficial 

 cells (fig. 34, a) are large and flattened; 

 they often have two nuclei. On their 

 under surface they exhibit depressions, 

 into which fit the larger ends of 

 pyriform cells, which form the next layer (fig. 34, b). Between the 

 tapered ends of the pyriform cells one or two layers of smaller poly- 



FIG. 33. CILIATED COLUMNAR 

 EPITHELIUM, FROM THE TRACHEA 

 OF A RABBIT. 



wii, m 2 , ?)i 3 , mucus-secreting cells in 

 various stages of mucigen formation. 

 The preparation was treated with 

 dilute chromic acid in the manner 

 recommended in the instructions 

 for practical work. 



FIG. 34. EPITHELIAL CELLS FROM THE BLADDER OF THE RABBIT. (Klein.) 

 (Magnified 500 diameters.) 



a, large flattened cell from the superficial layer, with two nuclei and with strongly marked 

 ridges and intervening depressions on its under surface ; 6, pear-shaped cell of the second 

 layer adapted to a depression on one of the superficial cells. 



hedral cells are found, 

 deeper cells. 



The epithelium is renewed by division of these 



