THE PELVIS 51 



The Pelvis or Pelvic Girdle 



False pelvis. The upper part, between the wings of the ilia. 

 It is broad and shallow. 



True pelvis.^The lower part, bounded by the pubes in front, 

 the ischia at the sides, and the sacrum and coccyx at the back. It 

 is deeper and narrower. 



The female pelvis has lighter bones, a wider pubic arch, and 



FIG. 46 THE PELVIS. (Morris.} 



greater capacity than the male pelvis; the sacrum is less curved and 

 the sacral promontory less projecting. 



The limiting line or boundary between the false and the true pelvis 

 is a curved line called the brim, and the space included is the inlet; 

 the lower opening is the outlet. The inlet and the outlet are also 

 known as the superior and inferior straits. The measurements or 

 diameters of these straits in the female pelvis are as follows : 



INLET (Edgar's Obstetrics) 



Antero-posterior 1 1 cm. 



(Symphysis to promontory.) 

 Oblique \2\ cm. 



(Ilio-pectineal joint to sacro-iliac joint.) 

 Transverse 13! cm. 



(Widest part of brim.) 



