THIGH AND LEG. 



333 



pudic vessels and nerves ; also the inferior pudendal nerve, a branch of the small 

 sciatic, distributed to the scrotum and side of the thigh. 



Dissection. Locate the greater sacro- sciatic ligament. Cut this ligament and 

 find under the same, in the lesser sacro-sciatic foramen, the main branches of the 

 internal pudic nerve and vessels. You will find two fair-sized branches given off. 

 Tuey will both be found to break up into numerous branches. Now carefully 

 trace these branches through the fat of the iscldo-rectal fossa the one to the 

 anus, the other forward to the perineum. The branch to the anus is the inferior 

 li&morrhoidal ; the other is the superficial perineal. Notice: (i) These branches 

 are both from the internal pudic ; (2) each divides into cutaneous and muscular 

 branches, for the supply of the muscles and the skin in these regions. The 

 arteries follow the nerves and take the same name. The internal pudic nerve 

 now continues in a canal called Alcock's. This nerve pierces the posterior 

 layer of the triangular ligament (Fig. 233), and gives off the following branches : 

 (i) The dorsal nerve of tlie penis ; (2) nerve to the bulb ; (3) nerve to the corpus 

 cavernosum ; (4) superficial perineal. This, the dorsal nerve of the penis, is the 

 largest division of the internal pudic nerve. You will find it on the inner sur- 

 face of the ramus of the ischium. It passes behind the superficial transversus 



Superficial dorsal vein of penis 



/Deep dorsal vein 

 Dorsal artery 



TUNICA ALBUGINEA 



Vessels 



TUNICA ALBUGINEA 



Artery 



Artery 

 URETHRA 

 CORPUS SPONGIOSUM 



FIG. 231. TRANSVERSE SECTION THROUGH THE BODY OK THE PENIS. 



perinaii muscle, gains the deep perineal space, pierces the anterior layer of the 

 deep perineal fascia, and is distributed to the dorsum of the penis. 



Crus Penis (Dissection of] and Its Muscle the Erector Penis, or IscJiio-cavern- 

 OS j {Sf The muscle covers the crus. Cut through the centre of the muscle in 

 the long diameter and turn the two halves aside. Notice its extensive origin : 

 (i) Tuberosity of ischium, (2) ramus of ischium, (3) surface of the crus. Trace 

 the muscle up to its insertion into the sides and under surface of the crus ; also 

 notice its nerves and vessels. Now cut through the thick, strong capsule of the 

 crus in its long diameter, and examine the erectile tissue of its interior. This 

 tissue is the specific element of the crus, and is called, in common with the 

 remainder of the lateral pyramid of the penis, the corpus cavernosum. Observe 

 the strong origin of the crus from the ischio-pubic ramus. 



Dissection of Accelerator Urimc and the Bulb. Depress the sound and make 

 the bulb, covered by the accelerator, stand out full. This muscle, as you see, is 

 in the mid-line, in front of the anus. The muscle being on the stretch, you will 

 now see in the middle a raphe separating the two halves. Now cut, with a very 

 sharp knife, through the center of this raphe and turn the muscle outward, and 

 thus expose the bulb. (Fig. 230.) Trace the muscle and note its insertions : (i) 



