CUTANEOUS NERVES ON THE FRONT. 



627 



and supplies the inner side of the foot and great Fig. 214. 



toe : it joins also the anterior tibial nerve. 



The outer branch ( 4 ) divides into three nerves ; 

 these lie over the three outer interosseous spaces, 

 and bifurcate at the web of the foot for the con- 

 tiguous sides of the four toes corresponding with 

 those spaces ; it joins the external saphenous 

 nerve on the outer part of the foot. 



The anterior tibial nerve (') becomes cutane- 

 ous in the first interosseous space, and is distri- 

 buted to that space, and to the opposed sides of 

 the great toe and the next. The musculo-cuta- 

 neous nerve joins it, and sometimes assists in 

 supplying the same toes. 



The external saphenous nerve (fig. 2 

 comes from the back of the leg below the 

 ankle, and is continued along the foot to the o\\t-//jt 

 side of the little toe ; all the outer margin of the J 

 foot receives nerves from it, and the offsets to- 

 wards the sole are larger than those to the dor- 

 sum. Occasionally it supplies both sides of the 

 little toe and part of the next. 



Internal saphenous nerve ( 5 ). A part of this 

 nerve is continued along the vein of the same 

 name to the middle of the instep, where it 

 ceases mostly in the integuments, but some 

 branches pass through the deep fascia to end in 

 the tarsus. 



The fascia of the front of the leg is thickest 

 near the knee joint, where it gives origin to 

 muscles. It is fixed laterally into the tibia and 

 fibula. Intermuscular septa are prolonged from 

 the deep surface ; and one of these, which is at- 

 tached to the fibula, separates the muscles on the 

 front from those on the outer side of the leg. 

 Superiorly the fascia is connected to the heads 

 of the leg bones, but inferiorly it is continued to 

 the dorsum of the foot. 



Above and below the ankle joint it is strength- 

 ened by some transverse fibres, and gives origin 

 to the two parts of the anterior annular ligament ; 

 and below the end of the fibula it forms another band, the external annular 

 ligament. 



Dissection. The fascia is to be removed from the front of the leg and 

 the dorsum of the foot, but the thickened band of the annular ligament 

 above and below the end of the tibia is to be left. In separating the 

 fascia from the subjacent muscles, let the edge of the scalpel be directed 

 upwards. 



In like manner the fascia may be taken from the peronei muscles on the 

 outside of the fibula, but without destroying the band (external annular 

 ligament) below that bone. 



On the dorsum of the foot the dorsal vessels with their nerve are to be 

 displayed, and the tendons of the short and long extensors of the toes are 



CtTTANF-ors NBRVES OF THE 

 FRONT OP THE LEO AND 

 FOOT. 



1. Anterior tibial. 



2. Muscalo-ciitaneous, with 3, 



its inner, and 4, its outer 

 piece; the usual distri- 

 bution is not shown in 

 the cat. 



5. Internal saphenous. 



6. Offsets of external popliteal. 



