228 ANATOMY AND PHYSIOLOGY FOR NURSES 



formed by the union of the second, third, and fourth lum- 

 bar nerves. It is distributed to the several muscles of the 

 thigh; at Poupart's ligament it separates, and is divided 

 into an anterior and a posterior part, which give off the 

 following branches, which supply the structures their 

 names imply. Anterior division: Middle cutaneous, in- 

 ternal cutaneous, long saphenous. Posterior division: 

 Muscular and articular. 



The sacral nerves are five in number on each side; 

 they pass through the sacral foramina, the last one 

 running between the coccyx and sacrum ; their function is 

 to supply the several pelvic organs. The COCCygeal 

 nerve supplies the coccygeus muscle and unites with the 

 fifth sacral. 



All the anterior cords of the sacral nerves communicate 

 with the sympathetic at the points where they leave the 

 sacral canal. 



The sacral plexus of nerves is composed of the 

 lumbosacral and the anterior branches of the three upper 

 and part of that of the fourth sacral nerves ; it gives off the 

 following branches: Visceral, muscular, superior gluteal, 

 pudic, small sciatic, and great sciatic. 



The great sciatic is a continuation of the main part 

 of the sacral plexus, forming the largest nerve in the body. 

 It supplies nearly the whole integument of the leg, the 

 muscles of the back of the thigh, and those of the leg and 

 foot. At the lower third of the thigh it divides into two 

 branches, the internal and external popliteal nerves. 



The internal popliteal nerve is a branch from the great 

 sciatic. This nerve with its branches supplies the pos- 

 terior part of the leg; it finally divides into the internal 

 and external plantar which supply the foot. 



The external popliteal is smaller than the internal; it 

 supplies the posterior muscles of the leg, and divides into 

 two branches the anterior tibial and musculocutaneous. 



