THE SUPERFICIAL FASCIA. 1043 



membranous aponeurosis. the fibres of which are directed obliquely downward 

 and inward. That portion of the aponeurosis which extends between the anterior 

 superior spine of the ilium and the spine of the os pubis is a broad band, folded 

 inward and continuous below with the fascia lata ; it is called Poupart's ligament. 

 The portion which is reflected from Poupart's ligament at the spine of the os pubis, 

 along the pectineal line, is called Grimbernat's ligament. From the point of attach- 

 ment of the latter to the pectineal line a few fibres pass upward and inward, 

 behind the inner pillar of the ring, to the linea alba. They diverge as they ascend, 

 and form a thin, triangular, fibrous band, which is called the triangular fascia of 

 the abdomen. 



The External or Superficial Abdominal Ring. Just above and to the outer side 

 of the crest of the os pubis an interval is seen in the aponeurosis of the External 

 oblique, called the external abdominal ring. This aperture is oblique in direction, 

 somewhat triangular in form, and corresponds with the course of the fibres of the 

 aponeurosis. It usually measures from base to apex about an inch,, and trans- 

 versely about half an inch. It is bounded below by the crest of the os pubis ; 

 abaYe, by a series of curved fibres, the intercolumnar, which pass across the upper 

 angle of the ring, so as to increase its strength ; and on either side, by the mar- 

 gins of the opening in the aponeurosis, which are called the columns or pillars of 

 the ring. 



The external pillar, which at the same time is inferior from the obliquity of 

 its direction, is the stronger ; it is formed by that portion of Poupart's ligament 

 which is inserted into the spine of the os pubis ; it is curved, so as to form a kind 

 of groove, upon which the spermatic cord rests. 



The internal or superior pillar is a broad, thin, flat band, which is attached 

 to the front of the body of the os pubis, interlacing with its fellow of the oppo- 

 site side in front of the symphysis pubis, that of the right side being superficial. 



The external abdominal ring gives passage to the spermatic cord in the male 

 and round ligament in the female ; it is much larger in men than in women, on 

 account of the large size of the spermatic cord, and hence the great frequency 

 of inguinal hernia in men. 



The intercolumnar fibres are a series of curved tendinous fibres which arch 

 across the lower part of the aponeurosis of the External oblique. They have 

 received their name from stretching across between the two pillars of the external 

 ring ; they increase the strength of the lower part of the aponeurosis and prevent 

 the divergence of the pillars from one another. They are thickest below, where 

 they are connected to the outer third of Poupart's ligament, and are inserted into 

 the linea alba, describing a curve, with the convexity downward. They are much 

 thicker and stronger at the outer angle of the external ring than internally, and 

 are more strongly developed in the male than in the female. These intercolumnar 

 fibres, as they pass across the external abdominal ring, are themselves connected 

 together by delicate fibrous tissue, thus forming a fascia which, as it is attached 

 to the pillars of the ring, covers it in, and is called the intercolumnar fascia. This 

 intercolumnar fascia is continued downward as a tubular prolongation around the 

 outer surface of the cord and testis, and encloses them in a distinct sheath ; hence 

 it is also called the external spermatic fascia. The sac of an inguinal hernia in 

 passing through the external abdominal ring receives an investment from the 

 intercolumnar fascia. 



If the finger is introduced a short distance into the external ring, and then, if 

 the limb is extended and rotated outward, the aponeurosis of the External oblique, 

 together with the iliac portion of the fascia lata, will be felt to become tense and 

 the external ring much contracted ; if the limb is, on the contrary, flexed upon the 

 pelvis and rotated inward, this aponeurosis will become lax, and the external ring 

 sufficiently enlarged to admit the finger with comparative ease ; hence the patient 

 should always be put in the latter position when the taxis is applied for the reduc- 

 tion of an inguinal hernia, in order that the abdominal walls may be relaxed as 

 much as possible. 



