450 A MANUAL OF ANATOMY 



supplying the integument of the in-ner side of the thigh in the 

 lower third. It finally turns outwards over the patella, and enters 

 into the patellar plexus. The posterior division descends along the 

 posterior border of the sartorius, and keeps beneath the fascia lata 

 until it reaches the level of the internal condyle of the femur. Here 

 it pierces the fascia lata, and descends to the inner side of the leg, 

 lying posterior to the long saphenous nerve, and supplying the 

 integument as low as the centre. The internal cutaneous nerve, 

 whilst in Scarpa's triangle, gives off two or three cutaneous branches, 

 which, having pierced the fascia lata, cross the femoral artery 

 and are distributed to the integument of the inner side of the 

 thigh in the middle third, along the course of the long saphenous 

 vein. The posterior division of the nerve gives off a branch to the 

 subsartorial plexus about the centre of the thigh on its inner aspect. 



Internal or Long Saphenous Nerve. — This is a branch of the pos- 

 terior division of the anterior crural nerve, and is deeply placed 

 as far as the knee-joint. In the lower two-thirds of Scarpa's 

 triangle it lies close to the outer side of the femoral artery, and in 

 Hunter's canal it gets in front of that vessel. It leaves Hunter's 

 canal at its lower end by piercing the aponeurotic roof, in company 

 with the superficial branch of the anastomotica magna artery, and 

 then it descends beneath the sartorius to the inner side of the knee- 

 joint. Here it pierces the fascia lata on a level with the lower 

 border of the sartorius, and enters the inner side of the leg, along 

 which it courses, usually in two divisions, in company with the 

 long saphenous vein, the larger division being behind that vessel, 

 and the smaller in front. At the ankle-joint the larger division 

 passes in front of the internal malleolus, and then along the inner 

 border of the foot as far as the centre. The long saphenous nerve, 

 in passing through Hunter's canal, gives off a branch which pierces 

 the aponeurotic roof, and enters into the subsartorial plexus. At 

 the level of the internal femoral condyle it furnishes its patellar 

 branch. This passes through the sartorius and fascia lata, and is 

 distributed to the integument over the front of the knee, where 

 it takes part in the patellar plexus. 



In its further course beyond the knee-joint the nerve supplies, 

 branches to the integument of the inner side of the leg, back of the 

 leg in its lower and inner part, internal malleolus, and inner side 

 of the foot as far as the centre. In the upper part of the leg it 

 communicates with the posterior division of the internal cutaneous 

 nerve, and on the inner side of the foot it is connected with the 

 musculo - cutaneous . 



Obturator Nerve. — The anterior division of the obturator nerve 

 usually furnishes a branch which pierces the fascia lata about the 

 centre of the thigh, between the posterior border of the sartorius 

 and the anterior border of the gracilis, to be distributed to thC' 

 integument for a variable distance. 



Patellar Plexus. — This free interlacement of nerves is so named 

 because it is situated over the anterior surface of the patella. 



