LUMBO- SACRAL PLEXUS. 



513 



The Great Sciatic nerve, the largest nerve in the body, 

 leaves the pelvis in company with the gluteal nerves, through the 

 great sciatic notch, and is directed downwards along the posterior 

 face of the femur. Near the stifle, it passes between the two 

 portions of the gastrocnemius muscle, where it forms two 

 branches ; a short one, which enters the muscles attached to the 

 posterior part of the tibia, and is distributed to the flexor pedis, 

 popliteus, and flexor pedis accessorius muscles ; and a principal 



Flu. 192. 



Lumbo-sacral plexus of the right side — the pelvis opeied a id viscera removed, a. First lumbar 

 nerve : a' a", Its branches ; 6, Second lumbar nerve : c. Inguinal branch : d. Femoral cutaneous : 

 e. Crtiral ; e'. Internal saphenic ; /, Obturator : g, Anterior; and h, Posterior gluteal; i, Posterior 

 cutaneous branch; fc. Internal pudic ; k', Its perineal branch : fc", Dorsal branch to the penis; I, 

 Haemorrhoidal ; to m, Great sciatic : m'. Posterior crural : m". External popliteal : m'", External 

 saphenic : n. Muscular branch ; o, TibiaL 



branch, the tibial or popliteal nerve, which descends at the 

 posterior part of the tibia, below the flexor perforatus, and 

 divides at the hock into external and internal metatarsal 

 branches. In its course, the sciatic nerve furnishes filaments to 

 all the muscles situated at the posterior part of the thigh, with 



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