Pig. 138. Sigmoid Flexure and Inguinal Canal. 



The Hypogastric and Iliac Regions are exposed on the left side of a normal 

 male cadaver — (aet. ^8). The tipper portion of the Abdominal Wall in this 

 region has been removed^ and the Ingiiinal Canal dissected ont, the Sigtnoid 

 thrown upwards and inwards, after accurately determining its positum (dotted 



lines). 



The Sigmoid Flexure which, variable in length, extends between the 

 Descending Colon — attached to the posterior Abdominal Wall — and the Rectum 

 — attached to the posterior Pelvic Wall — is the most movable portion of the 

 large intestine. 



The Sigmoid Flexure usuall}' possesses a lower (left) curve with its con- 

 vexity downwards, and an upper (right) curve with its convexity upwards. Such 

 are indicated by the dotted lines. When the Sigmoid is turned upwards, as in 

 the figure, a small peritoneal pouch over the left psoas becomes evident — the 

 Fossa Sigmoidea. 



Lying internal to the Psoas Muscle are seen (cf. Fig. 137) the Iliac 

 Vessels; above the divided Rectus Muscle is seen the Obliterated Hypogastric 

 Artery passing upwards towards the Umbilicus as the lateral vesico-umbilical 

 ligament in the Plica Umbilicalis. 



The fibres of the External Oblique Muscle of the Abdomen diverge in the 

 Inguinal Region forming the two pillars of the External Inguinal Ring, so that 

 the upper or inner pillar ends in the middle line at the Symphysis and the Sus- 

 pensor}' Ligament of the Penis or even extends beyond the middle line to the 

 Opposite side, whereas the inferior or outer pillar terminates at the Spine of the 

 Pubis. The upper sharp angle of the External Abdominal Ring, and the anterior 

 surface of the cord are covered by the Intercolumnar Fibres (removed in the 

 figure), the function of which is to prevent a wide divergence of the pillars. 



These intercolumnar fibres are derived from the External Oblique Muscle 

 of the opposite side and terminate by blending with PouPART's Ligament. 



Accordingly this ligament is formed by the External Oblique Muscles of 

 both sides and represents a tendon which most authors view as a band of con- 

 nection between two bony points or as the lower border of the External Oblique 

 Muscle. This latter view is probabl}' the more correct but it fails to take into 

 consideration the connection of this ligament with the Fascia Lata of the Thigh. 



Several small Ugaments, of which some have been named are connected 

 with Poupart's Ligament. 



There exists, occupying a horizontal position between the Pubis and Pou- 

 PART's Ligament, a triangular-shaped ligament, with its base directed outwards, 

 which is named GiMBERNAT's Ligament. When this structure is looked at from 

 above and behind it receives the name of CoLLES' Ligament. 



Its sharp outer edge is sometimes called the Falx Inguinalis (Ligament 

 of Henle). 



Internal and external to the Deep Epigastric Vessels lie respectively the 

 Internal and External Abdominal Rings ; between these is Hesselb ach's Ligament. 



