346 



HISTOLOGY 



The smooth muscle fibers are found everywhere between the pros- 

 tatic lobules; toward the urethra they thicken to form the internal sphinc- 

 ter of the bladder. Smooth muscle is also abundant on the surface of 

 the prostate, and it borders upon the striated fibers of the sphincter of the 

 membranous urethra. The prostate is abundantly supplied with blood 

 and lymphatic vessels. The numerous nerves form ganglionated plexuses 

 from which non-medullated fibers pass to the smooth muscles; others 

 of the nerves have free endings; still others, both in the outer and inner 



Red corpuscles in a 

 blood vessel. 



Connective tissue 



Epithelium. 



Smooth 

 muscle fibers. 



FIG. 348. FROM A SECTION OF THB PROSTATE OF A MAN TWENTY-THREE YEARS OLD. X 360. 

 The epithelium is cut obliquely at x, and has artificially separated from the connective tissue at xx. 



parts of the gland in dogs and cats, end in cylindrical lamellar corpuscles. 

 The utriculus prostaticus (uterus masculinus, vagina masculina) is a 

 small pocket lined with stratified epithelium, opening into the dorsal wall 

 of the urethra midway between the orifices of the ejaculatory ducts, or a 

 little below them. It is sometimes absent, and is occasionally quite deep. 

 Lowsley failed to find any small prostatic tubules opening into it, such 

 as have been reported as occasionally present. The utriculus prostaticus 

 is the lower end of the Mullerian ducts, which have fused, and it corres- 

 ponds with the vagina in the female. 



URETHRA AND PENIS. 



The form of epithelium found in the bladder extends through the 

 prostatic to the membranous part of the urethra. Its outer cells gradu- 



