REGIONS OF THE ABDOMEN 



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Regions of the Abdomen. Before the anatomy of the 

 abdominal part of the alimentary canal is described, it is 

 necessary to consider the plan adopted for the subdivision 

 of the abdominal cavity into certain arbitrary regions. The 

 following imaginary planes are utilised for the purpose. 



The subcostal plane passes horizontally through the body 

 on a level with the most dependent parts of the tenth costal 

 cartilages. Posteriorly, it cuts the vertebral column near the 



FIG. 87. Anterior Aspect of Trunk, showing the planes utilised for 

 the surface topography of the abdominal viscera. 



1. Transpyloric plane. 



2. Subcostal plane. 



3. Intertubercular plane. 



4. Right and left lateral planes. 



upper border of the third lumbar vertebra. The intertubercular 

 plane, which is parallel to the subcostal plane, passes through 

 the tubercles on the iliac crests and cuts the vertebral column 

 near the upper border of the fifth lumbar vertebra. These two 

 horizontal planes are intersected at right angles by two sagittal 

 planes, which pass through the mid-points of the two clavicles ; 

 they are known as the right and left lateral planes (Fig. 87). 

 By these four planes the abdominal cavity is divided into 

 nine regions, and the lines along which the planes cut the 

 surface of the anterior abdominal wall may be utilised in 



