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14 



OBSTETRICS. 

 Fig. 1. 



ilium. To different parts of the crest are attached the oblique and 

 transverse abdominal muscles, the latissimus dorsi, the erector spinae, 

 and the quadratus lumborum. It terminates anteriorly, in the ante- 

 rior superim' spinous process, and anterior inferior spinous pro- 

 cess,{*,'^) and posteriorly in the posterior superior and infericrr spinous 

 processes. i^,"^) The anterior superior spinous process gives attach- 

 ment to one end of Pouparfs or Gimbernafs ligament, the tensor 

 vagince femoris, and the sartorius muscles. From the anterior infe- 

 rior arises the longer portion of the rectus femoris. Into the posterior 

 are inserted strong ligaments, which bind this bone very firmly to 

 the sacrum. Below the posterior inferior spinous process there is a 

 deep arch, the sciatic notch, which is divided by ligaments into the two 

 sciatic foramina; through the itpper, which is the larger, pass the 

 gluteal, sciatic, and pudic arteries, the sciatic and pudic nerves, and 

 the pyriform muscle; through the inferior, the pudic arteries and 

 nerve re-enter the pelvis, and the obturator internus muscle passes 

 out. The posterior part of the crest is very rough, and marks the 

 connexion between the ilium and sacrum, called the sacro-iliac sym- 

 physis, of which there is one on each side of the sacrum. The 

 body of the bone is divided from the ala internally by a ridge running 

 horizontally,(") forming a portion of the pelvic brim, linea innbmi- 

 nata, or linea ilio-pectinea. The ilium is connected with the ischium 

 and pubis in the acetabulum, and posteriorly with the sacrum. 



Os ischium, is the second in size, and lowest in position of the divi- 

 sions of the innominatum. It is noted for a base or body, a spinous 

 process, its tuberosity, and ascending ramus. The base, or body, (Fig. 

 2,^) forms the inferior portion of the acetabulum, and is the thickest 



