1224 SURFACE AND SURGICAL ANATOMY. 
more especially the right lumbar region, and may extend upwards along the colon 
into the subdiaphragmatic region, or downwards into the true pelvis. To drain 
this region a tube is introduced into the right lumbar region either through the 
anterior abdominal wall or through the right loin. 
The peritoneal subdivision below the mesentery corresponds to the left umbilical, 
left lumbar, and left ihac regions, and is related to the duodeno-jejunal junction, the 
ereater part of the small intestine, part of the transverse colon, the splenic flexure, 
the descending colon, the iliac colon, the lower part of the left kidney, the left 
ureter, the lower part of the abdominal aorta, and the common iliac arteries. 
Suppuration in this division is very 
hable to extend downwards into 
the pelvis. Drainage may be estab- 
lished by the introduction of a tube 
either through the anterior ab- 
dominal wall or through the left 
lumbar region. If suppuration 
occur in the pelvis, drainage may 
be carried out through the anterior 
abdominal wall or, in the case of 
the female, through the vagina. 
Liver.—The lower border of the 
liver, as it crosses the costal angle, 
can readily be determined by palpa- 
tion and light percussion ; it passes 
from the eighth left to the tip of 
the tenth right costal cartilage, and 
crosses the mesial plane at the level 
of the transpyloric lne. In the 
mid-axillary line it reaches down 
to a point a little below the lowest 
part of the tenth right costal carti- 
lage. Above the left costal margin 
the lower border passes upwards 
and to the left to joi the left 
extremity of the liver at the fifth 
interspace in the mammary line. 
The highest part of the liver, which 
corresponds also to the highest part 
of the right arch of the diaphragm, 
reaches, during expiration, the level 
of the fourth intercostal space in 
the mammary line. To the right 
of the mesial plane the upper border 
of the liver is too far removed from 
the anterior wall of the chest, and 
7. ' overlapped by too thick a layer of 
Fic, 823.—LateraL AsPEct oF TRUNK, SHOWING SuRFACE Junge substance, to be accurately 
ca ee ree OF ON ISCER EG ai determined by percussion. Behind 
ih ee te Beal SEE panes the sternum the upper border reaches 
to the level of the sixth chondro- 
sternal junctions. To the left of the mesial plane the upper limit of the liver 
cannot be determined by percussion as it merges into the cardiac dulness. The 
falciform ligament of the liver lies, as a rule, a little to the right of the mesial plane. 
The anterior surface of the liver may be reached through a mesial incision 
extending downwards from the ensiform cartilage, or by an oblique incision a finger’s 
breadth below and parallel to the right costal margin. To obtain free access to the 
upper surface the eighth and ninth costal cartilages must be resected; the seventh 
cartilage should, if possible, be avoided, otherwise the pleural, and even the peri- 
cardial cavity, may be opened. Division of the round and falciform ligaments 
