328 THE MUSCLES OF THE TRUNK. 



latissimus dorsi. The lower and upper digitations of the external oblique are con- 

 nected with the ribs near their cartilages, the intermediate ones are attached to the 

 ribs at some distance from their extremities ; the lowest digitation generally embraces 

 the cartilage of the twelfth rib. The fleshy fibres from the last two ribs pass down 

 in a nearly vertical direction to be inserted into the external margin of the crest of 

 the ilium for about the anterior half of its length ; all the rest incline downwards 

 and forwards, and terminate in tendinous fibres, forming the broad aponeurosis by 

 which the greater part of the muscle is inserted. 



The aponeurosis of the external oblique muscle is wider below than above, and is 

 larger than that of either of the subjacent broad muscles. Consisting for the most 



Fig. 291. SUPERFICIAL VIEW OF THE 



MUSCLES OF THE ABDOMEN, FROM 

 BEFORE AND SLIGHTLY FROM THE 



SIDE. (Allen Thomson. ) \ 



14, 14, external oblique muscle ; 15, 

 placed over the ensiform process at the 

 upper end of the linea alba ; 15', umbi- 

 licus ; 16, symphysis pubis at the lower 

 end of the linea alba ; above 16, the 

 pyramidales muscles are seen, showing 

 through the abdominal aponeurosis ; from 

 the upper 14 to 17, the linea semilunaris ; 

 between this line and the linea alba are 

 seen the linese transversse ; above 22, the 

 curved margin of Poupart's ligament ; on 

 either side of 16, the external abdominal 

 ring is indicated. 



part of oblique fibres, which con- 

 tinue the direction of the muscular 

 fasciculi, it extends inwards to the 

 middle line in front, where it meets 

 its fellow of the opposite side in 

 the linea alba ; at some distance 

 from this line, but farther out 

 above than below, it becomes in- 

 separably united with the aponeu- 

 i osis beneath, and forms a part of 

 the sheath of the rectus muscle 

 i n the whole extent of the space 

 from the ensiform process to the 

 symphysis pubis. The upper part 

 of the aponeurosis is connected 

 with the pectoralis major, giving 



origin to the lowest fibres of that muscle. The lowest fibres of the aponeurosis are 

 closely aggregated together, and extend across from the anterior superior spine of the 

 ilium to the spine of the pubis, in the form of a thickened band, which is called 

 Pouparfs ligament. This ligament is curved with its convexity downwards owing 

 to the attachment of the iliac portion of the fascia lata to its lower border, but the 

 degree of curvature and the tension of the band vary with the position of the limb, 

 being increased with extension and eversion, and diminished with flexion and 

 inversion of the thigh. 



The aponeurosis is perforated by numerous small apertures for the passage of 

 cutaneous vessels and nerves, and near the body of the pubis by one large opening 

 which transmits the spermatic cord in the male or the round ligament in the female. 

 This is known as the superficial or external abdominal ring (external inguinal aper- 



