616 



NERVES OF THE LOWER LIMB. 



Fis. 



b. The miiscvlar branches are given off under cover of the biceps muscle ; they 

 supply the flexors of the leg, viz., the biceps, semitendinosus, and semimembra- 

 nosus. A branch is likewise given to the adductor magnus. 



Internal Popliteal 3S"erve. — The internal popliteal neiTe, the 

 larger of the two divisions of the great sciatic nerve, following the 

 same direction as the parent trunk, continues along the middle of the 

 popliteal space to the lower border of the popliteus muscle, beneath 

 which point the continuation of the trunk 

 receives the name o^jiosterior tibial. The in- 

 ternal popliteal nerve lies at first at a consider- 

 able distance from the popliteal artery, at the 

 outer side and nearer to the surface ; but, 

 from the knee-joint downwards, the nerve, 

 continuing a straight course, is close behind 

 the artery, and then crosses it rather to the 

 inner side. 



Fig. 377. — PosTERioii Cutaneous N'erves op the Leg 

 (from Sappey after Hirschfekl and Leveille). 



1, internal popliteal division of the great sciatic nerve ; 

 2, branch to the intei'nal part of the gastrocnemius 

 muscle ; 3, 4, branches to the external part and plan- 

 taris ; 5, communicating branch to the external saphe- 

 nous nerve ; 6, external popliteal nerve ; 7, cutaneous 

 branch ; 8, communicating branch descending to unite 

 with that from the internal popliteal in, 9, the external 

 saphenous nerve; 10, calcaneal branch from this nerve ; 

 11, calcaneal and jjlantar cutaneous branches from the 

 posterior tibial nerve ; 12, internal saphenous nerre ; 

 13, posterior branches of this nerve. 



Branches. — The internal popliteal nerve 

 supplies branches to the knee-joint and to 

 the muscles of the calf of the \Qg, and also 

 part of a cutaneous branch, the external or 

 short saphenous nerve. 



Articular Nerves. — The articular hrancJtes are 

 generally three in number : two of these accompany 

 the upper and lower articialar arteries of the inner 

 side of the knee-joint, the third follows the middle 

 or azygos artery. These nerves pierce the liga- 

 mentous tissue of the joint. — The upper one is often 

 wanting. 



Muscular Branches. — The muscular branches 

 of the internal poi^liteal nerve arise behind the 

 knee-joint, while the nerve is between the heads 

 of the gastrocnemius muscle. 



a. The nerves to the r/adrocyicmhts consist of two branches, which separate, 

 one to supply each part of the muscle. 



h. The small nerve of the jilantaris muscle is derived from the outer of the 

 branches just described, or cUrectly from the main truixk (internal popliteal). 



c. The mlcvs receives a branch of considerable size, which enters the muscle on 

 the posteiior aspect after descending to it in front of the gastrocnemius. 



d. The nerve of the jwj^Utexs muscle lies deeper than the preceding- branches, 

 and arises somewhat below the joint ; it descends along the outer side of the 

 popliteal vessels, and, after tm-ning beneath the lower border of the muscle, 

 enters the deep or anterior surface. 



