390 ABDOMEN 



It is merely the medial part of the folded-back margin of 

 the inguinal ligament which, in the vicinity of the pubic 

 tubercle, obtains an attachment to bone. 



The lacunar ligament occupies an oblique plane, its lower 

 or femoral surface looking distally and slightly forwards and 

 laterally, whilst its upper or abdominal surface looks upwards 

 and slightly backwards and medially. It is of importance 

 that the student should note the precise relation which this 

 ligament bears to the spermatic cord. Taken in conjunction 

 with the inguinal ligament and the aponeurosis of the external 

 oblique, it forms a groove in which the cord lies. 



Ligamentum Inguinale Reflexum (O.T. Triangular Fascia) 

 (Fig. 145). The lig. inguinale reflexum is a small triangular 

 piece of fascia which springs from the crest of the pubic 

 bone and the medial end of the pecten pubis. It passes 

 upwards and medially, under cover of the superior crus of 

 the subcutaneous inguinal ring, and passes into the linea 

 alba. If the fibres which compose it are followed through 

 the linea alba, they will be found to be continuous with the 

 fibres of the aponeurosis of the external oblique muscle of 

 the opposite side. It must, therefore, be considered as an 

 additional insertion of this muscle. It is, frequently, so 

 poorly developed that its true relations and connections are 

 demonstrated with difficulty, if indeed they are capable of 

 demonstration at all. 



Dissection. The internal oblique muscle should now be cleaned. 

 Towards its lower part it will be seen to be pierced by certain nerves, and 

 these must be preserved. Close to the iliac crest the lateral branches of the 

 ilio-hypogastric and last thoracic nerves will be noticed emerging from the 

 midst of its fleshy fibres, whilst anteriorly it is pierced by the anterior 

 branch of the ilio-hypogastric and by the ilio-ingutnal nerve. The former 

 of these appears near the anterior superior iliac spine, and then proceeds 

 medially under cover of the external oblique aponeurosis, which it soon 

 pierces. The ilio- inguinal nerve will be found perforating the internal 

 oblique a short distance medial to the hypogastric nerve and at a lower level. 

 It becomes superficial by passing through the subcutaneous inguinal ring. 



Care must be taken in defining the lower margin of the muscle to 

 preserve its relations to the spermatic cord, and not to injure the muscular 

 fasciculi which it gives to the cremaster muscle. 



M. Obliquus Abdominis Interims (Internal Oblique) (Fig. 

 142). The internal oblique muscle arises (i) from the 

 lateral half of the abdominal grooved surface of the inguinal 

 ligament ; (2) from the intermediate lip of the anterior 

 two -thirds of the iliac crest; (3) from the lumbar fascia. 



