THE MALE PERIX^EUM 



1123 



very slightly upwards, shouM enter the ineiuhninous un-tlira just in front of the 

 prostate. If i)usln'(l more deeply, it would enter the neck of the l)ladder. In lateral 

 lithotomy the knife is entered an inch and a half ( 87 mm. ) in front of tlie anus and 

 carried downwards and outwards for two and a half or tlnve inches (()2 to 75 mm.) into 

 the ischio-reetal fossa, ending a little helow and external to the mid-i)()int Ix.'twecn the 

 anus and tuher ischii. This incision hogins deeply and ends more su])<>rficially. In 

 the deeper part of the incision the knife is carried along the staff through the mem- 

 hranous urethra into the hladder. The parts divided in the operation are — skin, 

 superiicial fascia (hoth layers), transverse ])eriiueal vessels and nerves, sujjerficial 

 perinteal vessels and nerves, inferior Inemorrhoidal vessels and nerves, transversus 

 perina'i muscle, hase of triangular ligament (anterior layer), memhranous urethra 



Fiti. Gyl.— Thk Male Perinmccm. (Modified from Hirschfeld aud Leveille.) 



BUL80-CAVERN0SUS 



Superficial triangular ligament 

 ISCHIO-CAVERNOSUS 



Muscles of thigh 



y 



IXFERIOR PVDESDA L XER I 

 SLPERFICIAL PERINEAL NERVE 



INFERIOR HMMORRUOIDAL NERVE 

 CUTANEOUS BRANCH OF FOURTH SACRA I. 



Oluteus masimua 



TUBEROSITY OF ISCHIUM 

 Great sacro-sciatic ligament 

 Levator ani 

 Superficial transversus perinaei 



Sphin'^ter ani 



and deep muscles, a venous plexus, posterior layer of triangular ligament, prostatic 

 urethra, and left lohe of i)rostate and its cajisule in part, with some of the til)res 

 of the levator j)rf)stata^. In median lithotomy, an incision an inch and a half long 

 is made through the central tendinous point and raphe, so as to hit the memhra- 

 nous urethra. The following structures are divided: — Skin and fascia^; some of the 

 most anterior fihres of the sphincter ani; raphe and central tendinous point; minute 

 V)ranches of transverse jierinteal vessels and nerves; hase of triangular ligament in 

 centre; membranous urethra and compressor urethra'. 



The attachments and arrang(Miicnts of the superficial fascia (fig. G03) must he 

 traced and remembered. Of the two layers of which it consists, the sujierficial 

 alone extends over both urethral rectal triangles alike, and is continuous with the 

 similar structures in adjacent regions, the only difference being that, if tracecl for- 



