THE HIP BONE. 



233 



pubis) and an inferior (ramus inferior ossis pubis). The broad part of the bone 

 formed by the fusion of these two rami is the body. 



The body of the os pubis has two surfaces. Of these the posterior or postero- 

 superior is smooth, and forms the anterior part of the wall of the pelvis minor ; 

 hereto are attached the leva tor ani muscle and pubo-prostatic ligaments, and 

 on it rests the bladder. The anterior or antero-inferior surface is rougher, and 

 furnishes origins for the gracilis, adductor longus, adductor brevis, and some of 

 the fibres of the obturator externus muscles. The medial border is provided with 

 an elongated oval cartilage-covered surface (facies symphyseos) by means of which 

 it is united to its fellow of the opposite side, the joint being called the symphysis 

 pubis. The superior border, thick and rounded, projects somewhat, so as to over- 

 hang the anterior surface. It is called the crest. Medially this forms with the 

 medial border or symphysis the angle, whilst laterally it terminates in a pointed 

 process, the pubic tubercle (O.T. pubic spine). From the crest arise the rectus 



RECTUS FEMORIS (straight head of origin) 



RECTUS FEMOKIS (reflected head of origin) 

 ATTACHMENT OF 



ILIO-FEMORAL LIGAMENT ADDUCTOR LONGUS (origin) 



PYRAMIDALIS ABDOMINIS (origin) 

 RECTUS ABDOMINIS (origin) 



SEMIMEMBRAN- \ ' S < //Jf \ GRACILIS (origin) 



osus (origin) 



QUADRATUS |T %/,j;' 'Ifts^. ^ ^ //* JB ADDUCTOR BREVIS (origin) 



FEMORIS (origin) 

 BICEPS AND 

 SEMITENDINOS 



(origin) 



FIG. 232. MUSCLE ATTACHMENTS TO THE LATERAL SURFACE OF THE Os PUBIS AND ISCHIUM. 



abdominis and pyramidalis muscles, and to the tubercle is attached the medial 

 end of the inguinal ligament. Passing upwards and laterally from the lateral 

 side of the body towards the acetabulum, of which it forms about the anterior 

 fifth, is the superior ramus. This has three surfaces: an an tero- superior, an 

 antero-inferior, and an internal or posterior. The antero- superior surface 

 is triangular in form. Its apex corresponds to the pubic tubercle; its anterior 

 inferior border to the crista obturatoria (obturator crest), leading from the pubic 

 tubercle to the upper border of the acetabular notch ; whilst its sharp postero- 

 superior border trends upwards and laterally from the tubercle, and is continuous 

 with the iliac portion of the ilio-pectineal line just medial to the ilio-pectineal 

 eminence, forming as it passes along the superior ramus the pubic portion of 

 that same line (pecten ossis pubis). On this line, just medial to the ilio-pectineal 

 eminence, there is often a short sharp crest which marks the insertion of the 

 psoas minor. The base of the triangle corresponds to the ilio-pectineal eminence 

 above and the upper margin of the acetabular notch below. Slightly hollow 

 from side to side, and convex from before backwards, this surface provides an 

 origin for, and is in part overlain by, the pectineus muscle. The posterior 

 or poster o -superior surface of the superior ramus is smooth, concave from side to 

 side, and slightly rounded from above downwards; by its sharp inferior curved 

 border it completes the obturator foramen, as seen from behind. The antero- 



