130 



DISSECTION OF THE THIGH. 



External 

 popliteal 

 nerve : 



course 



and ending ; 



branches, 

 articular, 



peroneal 

 communi- 

 cating, 



and lateral 

 cutaneous 

 of leg. 



Articular 

 nerve of the 

 obturator. 



Lymphatic 

 glands 

 around the 

 artery. 



The EXTERNAL POPLITEAL NERVE (peroneal ; fig. 5 1, 3 ) lies along 

 the outer boundary of the ham, and is at first concealed by the 

 edge of the biceps muscle ; becoming superficial, it is continued 

 over the outer head of the gastrocnemius, following the hinder 

 border of the biceps tendon, until it is below the head of the fibula. 

 There it enters the fibres of the peroneus longus, and divides 

 beneath that muscle into two musculo-cutaneous and anterior 

 tibial. Its branches are articular and cutaneous : 



a. The articular nerve, arising high in the space, runs with the 

 upper external articular artery to the outer side of the knee, and 

 sends a twig along the lower articular artery : both enter the 

 joint. 



6. The peroneal communicating branch (fig. 71, 4 , p. 188) soon 

 pierces the fascia, and descends over the outer head of the gastro- 

 cnemius to join the tibial communicating from the internal popliteal 

 in the short saphenous nerve. 



c. One or two lateral cutaneous branches aiise either in common 

 with the preceding or separately, and supply the skin of the outer 

 side of the leg, reaching nearly to the external malleolus. 



The ARTICULAR BRANCH OF THE OBTURATOR NERVE (fig. 53, 7 ) 



perforates the adductor inagnus (p. 164), and is conducted by the 

 popliteal artery to the back of the knee. After supplying filaments 

 to the vessels, the nerve enters the articulation through the posterior 

 ligament. 



The POPLITEAL LYMPHATIC GLANDS are situate round the large 

 arterial trunk. Two or three are ranged on the sides ; while one 

 is superficial to, and another beneath the vessel : they are joined by 

 the deep lymphatic vessels, and by the superficial set with the 

 external saphenous vein. 



Dissect the 

 back of the 

 thigh. 



Seek out 

 cutaneous 

 nerves : 



clean 



muscles and 

 nerves. 



Three 

 muscles on 

 back of 

 thigh : 



situation. 



THE BACK OF THE THIGH. 



Dissection (fig. 53). After the popliteal space, the student 

 may proceed with the dissection of the back of the thigh. The 

 piece of skin between the buttock and the ham should be divided 

 in the middle line and reflected to the sides. In the fat on the 

 outer side of the lirnb fine offsets of the external cutaneous nerve 

 of the thigh may be found ; and along the middle some filaments 

 from the small sciatic nerve pierce the fascia. 



Remove the deep fascia of the limb, taking care of the .si null 

 sciatic nerve and its artery. Lastly, clean the hamstring muscles ; 

 trace the arteries from the front of the thigh, which perforate the 

 muscle to get to the back ; and clean the branches of the great 

 sciatic nerve to the muscles. 



MUSCLES. The muscles behind the femur are flexors of the 

 knee-joint. They reach from the pelvis to the bones of the leg, 

 and are named hamstrings from the cord-like appearance on the 

 sides of the ham. They are three in number, viz., biceps, semi- 

 tendinosus, and semimembranosus. The first of these lies on the 

 outer, and the other two on the inner side of the popliteal space. 



