160 



DISSECTION OF THE THIGH. 



Anterior 

 crural nerve 



divides into 

 two parts. 



From its 

 superficial 

 part arise 

 middle 

 cutaneous ; 



internal 

 cutaneous, 



which has 

 anterior and 



posterior 

 branches ; 



nerve to 

 pectineus ; 



branches to 

 sartorius. 



The deep 

 part gives 

 off branches 



to rectus, 



to vastus 

 externus, 



to crureus, 



and to 



vastus 

 internus : 



the vastus externus muscle in company with the nerve to the same, 

 and anastomoses with the upper external articular artery ; a small 

 offset courses over the muscle with a nerve to the joint. 



The ANTERIOR CRURAL NERVE (fig. 59) derived from parts of 

 the second, third and fourth lumbar nerves supplies the muscles, 

 and most of the integuments of the front of the thigh, and the 

 integuments of the inner side of the leg. Soon after the trunk 

 of the nerve leaves the abdomen and enters the thigh immediately 

 external to the common femoral artery it is flattened, and is divided 

 into superficial and deep divisions. 



A. The SUPERFICIAL DIVISION gives off the middle and internal 

 cutaneous nerves, and branches to the sartorius and pectineus muscles. 



The middle cutaneous nerve perforates the fascia lata, sometimes 

 also the sartorius, about three inches below Poupart's ligament, and 

 extends to the knee (p. 141). 



The internal cutaneous nerve sends two or more small twigs 

 through the fascia lata to the integument of the upper two-thirds of 

 the thigh, and then divides in front of the femoral artery, or on the 

 inner side, into anterior and posterior branches. Sometimes these 

 branches arise separately from the anterior crural trunk. 



The anterior branch is directed to the inner side of the knee. 

 As far as the middle of the thigh it lies over the sartorius, but it 

 then pierces the fascia lata, and ramifies in the integuments 

 (p. 141). 



The posterior branch remains beneath the fascia lata as far as 

 the knee. While underneath the fascia the nerve lies along the 

 inner border of the sartorius, and joins in a plexus, about the 

 middle of the thigh, with offsets of the obturator, and nearer the 

 knee, with a branch of the internal saphenous nerve. 



The nerve to the pectineus (fig. 57, 2 , p. 147) is slender, and is 

 directed inwards beneath the femoral vessels to the anterior surface 

 of the muscle : sometimes there are two branches. 



Two or three branches to the sartorius arise in common with the 

 middle cutaneous nerve. 



B. The DEEP DIVISION of the anterior crural nerve furnishes 

 branches to the several heads of the quadriceps extensor muscle, 

 and one cutaneous nerve the long, or internal, saphenous. 



The branch to the rectus enters the deep surface of the muscle ; 

 from this branch a twig is sent to the hip-joint. 



The nerve to the vastus externus divides into two or more parts 

 as it enters the muscle. From one of these an articular filament is 

 often continued downwards to the knee-joint. 



Two or three branches to the crureus pass into the anterior surface 

 of the muscle ; and from the most internal a long twig descends to 

 the subcrureus and the knee-joint. 



The nerve to the vastus internus (fig. 62, 8 , p. 165) is nearly as 

 large as the internal saphenous, in common with which it often 

 arises. To the upper end of the vastus it furnishes one or more 

 branches, and is then continued as far as the middle of the thigh, 

 where it ends in offsets to the muscle and the knee-joint. 



