ANTERIOR CRURAL NERVE. 660 



when that branch springs from or near the lumbar plexus. In either case, its ulti- 

 mate distribution is the same as that already described. 



Terminal branches. From the principal or terminal divisions of the nerve 

 the remaining branches take their rise as follows. 



From the SUPERFICIAL DIVISION cutaneous branches are given to the fore 

 part of the thigh, and to the inner side of the leg. They are the middle and 

 internal cutaneous nerves, and the internal saphenous nerve. One of the 

 muscles, the sartorius, receives its nerves from this group. 



The DEEP BRANCHES supply the muscles on the fore part of the thigh, and 

 also the pectineus muscle. The branch to the pectineus, however, some- 

 times arises from the superficial part of the trunk. 



A. MUSCULAR BRANCHES. 



The branch to the pectineus muscle crosses inwards behind the femoral vessels, 

 and enters the muscle on the anterior aspect. 



The sartorius muscle receives three or four twigs, which arise in common with 

 the cutaneous nerves, and reach mostly the upper part of the muscle. 



The rectus muscle receives a distinct branch on its under surface. 



The nerve for the vastus externus, of considerable size, descends with the branches 

 of the external circumflex artery towards the lower part of the muscle. It gives oft 

 a long slender articular filament, which reaches the knee and penetrates the fibrous 

 capsule of the joint. 



Another large nerve divides into two sets of branches, which enter the vastus 

 internus and the crureus about the middle of those muscles. The nerve of the vastus 

 internus, before penetrating the muscular fasciculi, gives a small branch to the knee- 

 joint. This articular nerve passes along the internal intermuscular septum with a 

 branch of the anastomotic artery, as far as the inner side of the joint, where it per- 

 forates the capsular ligament, and is directed outwards on the synovial membrane 

 beneath the ligamentum patellae. 



B. MIDDLE CUTANEOUS NERVE. 



The middle cutaneous nerve either pierces the fascia lata divided into two 

 branches about four inches below Po apart' s ligament, or as one trunk which 

 soon separates into two branches. These branches descend side by side on the 

 fore part of the thigh to the inner side and front of the patella. After or 

 before the nerve has become subcutaneous, it communicates with the crural 

 branch of the genito-crural nerve, and also with the internal cutaneous. 



This nerve sometimes arises from the anterior crural, high up within the 

 abdomen. 



C. INTERNAL CUTANEOUS NERVE. 



The internal cutaneous nerve gives branches to the skin on the inner side 

 of the thigh, and the upper part of the leg ; but the extent to which it 

 reaches varies with the presence or absence of the " occasional cutaneous" 

 branch of the obturator nerve. 



Lying beneath the fascia lata, this nerve descends obliquely over the 

 upper part of the femoral artery. It divides either in front of that vessel, 

 or at the inner side, into two branches (one anterior, the other internal), 

 which pierce the fascia separately. These two branches sometimes arise as 

 distinct offsets from the superficial part of the anterior crural nerve. 



The distribution of the internal cutaneous nerve is as follows. 



(a) Branches previous to division. Before dividing into its two ultimate 

 branches, this nerve gives off two or three cutaneous twigs, which accompany the 

 upper part of the long saphenous vein. The highest of these perforates the fascia 



