THE PUD END AL PLEXUS 1063 



The internal branch, the continuation of the nerve, accompanies the dorsalis 

 pedis artery along the inner side of the dorsum of the foot, and at the first inter- 

 osseous space divides into two dorsal digital branches (////. digitales dorsales hal- 

 lucis lateralis et digiti secundi medialis), which supply the adjacent sides of the 

 great and second toes, communicating with the internal branch of the musculo- 

 cutaneous nerve. Before it divides it gives off to the first space an interosseous 

 branch which supplies the metatarsophalangeal joint of the great toe and sends a 

 branch to the First dorsal interosseous muscle. 



The Musculocutaneous Nerve (n. peronaeus superficialis) (Fig. 771) supplies the 

 muscles on the fibular side of the leg and the integument over the greater part 

 of the dorsum of the foot. It passes forward between the Peronei muscles and 

 the Extensor longus digitorum, pierces the deep fascia at the lower third of the 

 leg on its front and outer side, and divides into two branches. This nerve in 

 its course between the muscles gives off muscular branches to the Peroneus longus 

 and brevis, and cutaneous branches to the integument of the lower part of the leg. 



The internal dorsal cutaneous branch (n. cutaneus dorsalis medialis) of the muscu- 

 locutaneous nerve passes in front of the ankle-joint, and divides into three dorsal 

 digital branches (nn. digitales dorsales pedis). The internal branch supplies the 

 skin of the dorsum of the foot and the inner side of the great toe, and communicates 

 with the internal saphenous nerve. The intermediate branch runs to the space 

 between the great and second toes, supplies the adjacent sides of these, and com- 

 municates with the anterior tibial nerve. The external branch passes to the 

 space between the second and third toes and supplies the adjacent sides of these. 



The external dorsal cutaneous branch (n. cutaneus dorsalis intermedium), the 

 smaller, passes along the outer side of the dorsum of the foot, and divides into two 

 dorsal digital branches, the inner being distributed to the adjacent sides of the 

 third and fourth toes, the outer to the adjacent sides of the fourth and fifth toes. 

 It also supplies the integument of the outer ankle and outer side of the foot and 

 communicates with the external saphenous nerve. 



The branches of the musculocutaneous nerve supply all the toes excepting the 

 outer side of the little toe, which is supplied by the small saphenous nerve. The 

 adjoining sides of the great and second toes are also supplied by the internal branch 

 of the anterior tibial. It frequently happens that some of the outer branches of 

 the musculocutaneous are absent, their place being then taken by branches of 

 the external saphenous nerve. 



THE PUDENDAL PLEXUS (PLEXUS PUDENDUS). 



The pudendal plexus (Fig. 774) is not sharply marked off from the sacral 

 plexus, some of the branches which spring from it may arise in conjunction with 

 those of the sacral plexus. It lies on the posterior wall of the pelvis and is usually 

 formed by branches from the ventral primary divisions of the second and third 

 sacral nerves, the whole of the anterior primary divisions of the fourth and fifth 

 sacral nerves, and the coccygeal nerve. 



It gives off the following branches. 



Perforating cutaneous (variable) ..... . (2, 3. S.) (3, 4, S.) (4, 5, S.) 



Pudic . . . . 2, 3, 4, S. 



Visceral 3,4,8. 



Muscular 4, S. 



Anococcygeal . 4, 5, S, and Cocc. 



The Perforating Cutaneous Nerve (n. clunium inferior medialis) (Fig. 774) 

 is not always present- It sometimes arises from the second and third sacral 



