THE LOWER LIMB 449 



tiepiession on either side of the ligamentum patellae, however, is not 

 present, this being due to the lateral dispersion of the fat which 

 normally lies underneath the ligamentum patellae. 



Cutaneous Nerves. Femoral Branch of Genito-femoral Nerve. — 

 The genito-femoral nerve is a branch of the lumbar plexus, its fibres 

 being derived from the first lumbar and the ventral division of the 

 second lumbar nerves. Its femoral branch emerges beneath Poupart's 

 ligament immediately to the outer side of the femoral artery, and 

 within the femoral sheath. Having supplied a twig to the coats 

 of that vessel, it pierces the sheath and the fascia lata, to be dis- 

 tributed to the integument over Scarpa's triangle. 



Inguinal Nerve (Eio-inguinal). — This is a branch of the lumbar 

 plexus, its fibres being derived from the first lumbar nerve. It 

 emerges from the inguinal canal through the external abdominal 

 ring, where it lies directly to the outer side of the spermatic cord, 

 or round ligament of the uterus, according to the sex. It then 

 pierces the intercolumnar fascia, and is distributed to the integu- 

 ment of the inner side of the thigh in the upper third, and to the 

 adjacent integument of the scrotum in the male and the labium 

 majus in the female. 



External Cutaneous Nerve. — This is a branch of the lumbar 

 plexus, its fibres being derived from the dorsal divisions of the 

 second and third lumbar nerves. It emerges beneath the outer 

 end of Poupart's ligament, and shortly afterwards divides into a 

 small posterior and a large anterior division. The -posterior division 

 is distributed to the integument of the outer side of the thigh in 

 the upper fourth, and also to the integument of the outer and lower 

 part of the gluteal region. The anterior division is at first contained 

 in a tube of the fascia lata for about 4 inches, and then it enters 

 the integument of the outer side of the thigh which it supplies, 

 reaching in some cases as low as the patella, and taking part in 

 the patellar plexus. 



Middle Cutaneous Nerve. — This is a branch of the anterior 

 division of the anterior crural nerve. It pierces the fascia lata in 

 two divisions, outer and inner, about 4 inches below Poupart's 

 ligament. The outer division usually passes through the upper 

 part of the sartorius, and then descends with the inner division 

 to supply the integument of the front of the thigh in the lower 

 two-thirds. The two divisions extend as low as the patella, where 

 they take part in thej,patellar plexus. 



Internal Cutaneous Nerve. — This is a branch of the anterior 

 division of the anterior crural nerve. It crosses over the femoral 

 artery from without inwards near the apex of Scarpa's triangle, 

 ; either as one nerve, or in its two final divisions, anterior and posterior. 

 These two divisions now descend on the inner side of the thigh 

 beneath the fascia lata, and along the line of the long saphenous 

 vein. At the junction of the middle and lower thirds of the thigh 

 • the anterior division pierces the fascia lata, and descends near the 

 ' tendon of the adductor magnus to the inner side of the knee-joint, 



