424 



CRURAL NERVE. 



of the internal oblique and transversalis, is distributed to the iateguirje.it 

 of the groin. The crural branch (lumbo-inguinalis), the most external of 

 the two, descends along the outer border of the external iliac artery, and, 

 crossing the origin of the circumflex ilii artery, enters the sheath of the 

 femoral vessels in front of the femoral artery. It pierces the sheath below 

 Poupart's ligament, and is distributed to the integument of the anterior 

 aspect of the thigh as far as its middle. This nerve is often very small, 

 and sometimes communicates with one of the cutaneous branches of the 

 crural nerve. 



The CRURAL, or FEMORAL NERVE, is the largest 

 of the divisions of the lumbar plexus ; it is formed 

 by the union of branches from the second, third, 

 and fourth lumbar nerves, and, emerging from 

 beneath the psoas muscle, passes downwards in 

 the groove between it and the iliacus, and beneath 

 Poupart's ligament into the thigh, where it spreads 

 out and divides into numerous branches. At 

 Poupart's ligament it is separated from the femo- 

 ral artery by the breadth of the psoas muscle, 

 which at this point is scarcely more than half an 

 inch in diameter, and by the iliac fascia, beneath 

 which it lies. 



Branches. While situated within the pelvis the 

 crural nerve gives off several muscular branches 

 to the iliacus, and one to the psoas. On emerg- 

 ing from beneath Poupart's ligament the nerve 

 becomes flattened and divides into numerous 

 branches, which may be arranged into, 



Cutaneous, 



Muscular, 



Branch to the femoral sheath, 



Short saphenous nerve, 



Long saphenous nerve. 



The Cutaneous nerves (middle cutaneous) twc 

 in number, proceed from the anterior part of the 

 crural, and after perforating the sartorius muscle 

 to which they give filaments, pierce the fascia lata 

 and are distributed to the integument of the mid- 

 dle and lower part of the thigh and of the knee. 

 The most external of these nerves perforates the 

 upper part of the sartorius, communicates with the 

 crural branch of the genito-crural, divides into two branches at about the 

 middle of the thigh, and gives off* numerous filaments to the anterior and 

 outer aspect of the limb as far as the patella. The internal nerve perfo- 

 rates the muscle at about its middle, pierces the fascia lata at the lower 

 third of the thigh, descends to the inner condyle, and curves forward to 

 the front of the knee, supplying the integument by many filaments. Be- 

 sides these another cutaneous branch derived from the muscular branch 



* A view of the anterior crural nerve and branches. 1. Place of emergence of the 

 nerve rider Ponpart's ligament. 2. Division of the nerve into branches. 3. Femoral 

 aitery 4. Femoral vein. 5. Branches of obturator nerve. 6. Nervus saphenus 



