THE ABDOMEN, EXTERIOR. 435 



sions at the ensiform, umbilicus, and midway between the 

 two. These transverse markings correspond to the tendin- 

 ous intersections in the recti muscles. 



ABDOMINAL REGIONS. Figs. 87, 98. 



The abdomen is arbitrarily divided into regions by four 

 lines, two horizontal and two vertical. The horizontal 

 lines are drawn, one connecting the anterior superior spines 

 of the ilium, the other between the tips of the cartilages of 

 the tenth ribs. The vertical lines are formed by erecting 

 a perpendicular at the middle of Poupart's ligament on each 

 side. 



The regions thus formed are named as follows, from 

 right to left. The first tier : The right hypochondriac, the 

 epigastric, the left hypochondriac. The second tier : The 

 right lumbar, the umbilical, and the left lumbar. The 

 third tier : The right inguinal, the hypogastric, the left 

 inguinal. 



The portions of the viscera that lie in the above regions 

 may be determined approximately by consulting Figs. 96 

 to 1 06. It is to be noted that these relations are not constant 

 for the same subject at different times, or for any two 

 subjects at the same time. At best they are only relative. 



The surface area of the various viscera will be given in 

 connection with the description of those viscera. 



DISSECTION. 



Shave or cut the hair from the pubes. 



Incisions. (i) From the ensiform to the symphysis, then along the dor- 

 sum of the penis. 



(2) Transversely around the thorax at the level of the ensiform. 



(3) From the symphysis outward, following the direction of Poupart's liga- 

 ment and the crest of the ilium. 



Remove the integument only, from this area. 



