96 OSTEOLOGY, OR ANATOMY OF OSSEOUS SYSTEM 



facing inward is a long oval surface marked by transverse 

 ridges or nipple-like processes for articulation with the opposite 

 bone; the junction is the symphysis pubis. The part passing 

 down and out from the symphysis is the descending ramus; 

 the upper part is the superior or ascending ramus; and the 

 flat portion between the rami is the body. The pelvic surface 

 of the body is smooth, the anterior surface rough. Anteriorly 

 at the upper extremity of the symphysis is the angle; extending 

 out from thfs on the superior border is the crest, terminating 

 in the spine. The descending ramus is thin and flat, and joins 

 that of the ischium at a point a little more than half-way from 

 the body of the pelvis to the tuberosity of the ischium. The 

 superior ramus becomes prismatic, ending externally at the 

 acetabulum, of which it forms about one-fifth; its superior 

 border is the pubic portion of the iliopectineal line, running 

 from the spine of the pubis to the internal aspect of the ilio- 

 pectineal eminence. The triangular surface in front of this 

 line gives origin to the pectineus muscle; below is the obturator 

 crest, extending from the pubic spine to the margin of the 

 acetabulum. Behind the outer part of this crest on the inferior 

 surface of the ramus is the obturator groove, directed from behind 

 forward and inward. 



The pubic crest gives origin to part of the conjoined tendon, 

 the pyramidalis and rectus abdominis. To the pubic spine 

 are inserted Poupart's ligament and the outer pillar of the 

 external abdominal ring. From the front of the pubis, in the 

 angle between the crest and the symphysis, arises the adductor 

 longus muscle, and below this the adductor brevis and part 

 of the adductor magnus. Internal to these the gracilis is 

 attached, and external the obturator externus. Posteriorly 

 the pubis gives attachment to the obturator internus; above 

 this is sometimes a faint line passing from the upper margin 

 of the obturator foramen to the lower end of the symphysis; 

 the levator ani muscle is attached to it, and the obturator and 

 rectovesical fasciae. 



The Ischium 



The -ischitini forms the lower and back part of the hip bone, 

 bounds the thyroid foramen below, and forms over two-fifths 

 of thejacetabulum. It presents a body, and below this a tuber- 



