THE ABDOMEN 



1143 



horizontal line and plane passes through the level of the anterior superior iliac 

 spines, and dorsally about 2.5 cm. below the promontory of the sacrum. Cun- 

 ningham has proposed that this line be passed through the tuberculum cristas, 

 therefore in a plane slightly higher than the interspinous plane. For the longitu- 

 dinal lines and planes it has been customary to run vertical lines parallel with the 

 mid-body line or mid-sagittal plane, and from the middle of the inguinal ligaments. 

 The outer border of each rectus would seem, however, preferable as a guide for 

 these longitudinal lines and planes, which may be easily localised above by the 

 lateral infra-costal furrow and below by the pubic spines, leaving thus on each side 

 an inguinal region which includes the whole of the inguinal canal. The boundary 

 lines here indicated may be made intelligible by a reference to fig. 898. The 

 regions thus outlined are known as the right and left hypochondriac and epigas- 

 tric regions, found above the upper horizontal line; the right and left lumbar and 

 the umbilical regions, found between the two horizontal lines; the right and left 



Fig. 



899. — The Adbominal Viscera in Situ, after Removal of the Anterior Abdom- 

 inal Wall. (After Sarazin.) 



Diaphragm 



Liver 



Falciform ligament 

 of liver 



Transverse colon 



Great omentum 



Small intestine 



Cscum 



Bladder 



Sigmoid colon) 



inguinal or iliac and the hypogastric regions, found below the lower horizontal lines. 

 (According to the BNA, the lumbar regions are termed 'lateral abdominal'.) 



On freely laying open an abdomen from the front, the general form of the space 

 is seen to be an irregular hexagon, the sides of which are formed as follows: — The 

 upper two by the margins of the costal cartilages with the ensiform cartilage 

 between; the two lateral sides by the edges of the lateral boundary; and the two 

 lower by the two inguinal ligamentb which meet at the pubes. 



In this irregular hexagon the following organs can be observed without dis- 

 arranging their normal position (fig. 899). Above, on the right side, under the 

 costal cartilages, can be seen the liver, which extends from the right across the 

 median line to a point below the left costal cartilages. Below the liver, and lying 

 to the left side, can be seen the anterior surface of the stomach; from the lower 

 border of the stomach the omentum extends downward, and shining tlirough it 

 can be seen the middle part of the transverse colon. On each side and below the 



