Muscles of the Abdomen. 



163 



217. The Long Abdominal Muscles. 



M. rectus abdominis arises from the outer surface of the cartilages of the fifth to 

 the seventh ribs and the xiphoid appendix, being inserted into the upper border and 

 anterior surface of the Symphisis pulis. The fibrous sheath of the Rectus abdominis 

 formed by the aponeuroses of the broad abdominal muscles, covers the whole 

 of its anterior surface, while on its posterior surface it ends two or three fingers 

 breadth below the umbilicus as Linea semicircularis Douglasii (semi-lunar fold of 

 Douglas) (see Fig. 219). 



M. pyramidalis abdominis arises from the upper border of the pubis and 

 is inserted into the fibrous sheath (Vagina fibrosa) of the Rectus abdominis. 



21* 



