PHYSIOLOGIC APPARATUS 



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the pelvic cavity, it passes down the thigh between the semi-membranosus 

 and the biceps muscles, in company with the femoral blood-vessels. Below 

 the knee it divides into the tibialis and peroneus nerves; the former sending 

 branches into the gastrocnemius. In its course, the sciatic sends branches 

 to the muscles of the entire leg. 



Carefully separate the biceps and semimembranosus by tearing the 

 connective tissue uniting them. The sciatic nerve and femoral blood- 

 vessels come into view; with a bent glass rod gently separate the nerve 

 from its surroundings from the knee to the thigh. Begin at the knee. In 

 order to expose the nerve at the pelvis, it will be necessary to divide the 

 pyriformis and the ileo-coccygeus muscles. Care must here be exercised, 

 so as not to injure the nerve which lies immediately beneath. Lift up the 

 urostyle with the forceps and separate it from the last vertebra. With 



ci 



the scissors cut off the vertebral column above the seventh vertebra. Place 



he legs on the dorsal surface and then divide the seventh eighth and mn^ 



vertebra lengthwise. With the forceps lift up one lateral hal of the vertebra 



aid free the nerve as far as the knee by dividing connective tissue and nerve 



Theompleted preparation consists of the gastrocnemius muscle the sci- 

 atfc nervt with half of the seventh, eighth, and ninth vertebra and the lower 



half of the femur. 



