SURGICAL ANATOMY OF THE ABDOMEN 7 



an anterior, middle, and posterior region ; but in order to 

 prevent confusion we will number these regions —thus, 

 the anterior, middle, and posterior regions of the superior 

 zone will be i, 2, 3, whilst the same regions of the 

 inferior zone will be 4, 5, 6 (see Fig. i). Regions i, 2, 

 and 3 would be respectively the superior diaphragmatic, 

 lumbar, and pelvic regions, whilst 4, 5, and 6 would be 

 the inferior diaphragmatic, lumbar, and pelvic regions. 

 The largest region is the inferior, and the smallest the 



Fig. I. — Surgical Regions of the Abdomen. 



I, Superior diaphragmatic ; 2, superior lumbar; 3, superior pelvic ; 



4, Inferior diaphragmatic; 5, inferior lumbar ; 6, inferior pelvic. 



superior diaphragmatic. We shall find these landmarks 

 of great use to us in studying the relation of the viscera 

 to its walls. 



The cavity of the abdomen is nearly ovoid ; its long 

 axis is directed obliquely from above downwards and 

 forwards ; it is bounded anteriorly by the diaphragm, 

 posteriorly by the pelvis, laterally and inferiorly by its 

 walls, and superiorly by the lumbar portion of the spine. 

 In order to thoroughly comprehend the arrangement 

 of the abdominal viscera, it is absolutely necessary to 

 bear in mind the direction of this cavity and that of the 

 diaphragm. 



