THE ABDOMINAL CAVITY. 1229 
hepatic flexure of the colon; the upper part lies deeply in the hypochondrium, and 
is felt by thrusting the hand upwards and backwards between the liver and the 
hepatic flexure of the colon. Between this part of the kidney and the renal sur- 
face of the liver is a deep recess which receives its serous covering from peri- 
toneum continued upwards from the upper layer of the transverse mesocolon. 
Overlapping the hilus and the lower part of the inner border is the descending 
part of the duodenum, which is crossed by the transverse colon. : 
The lower half of the left kidney, covered by peritoneum continued downwards 
from the lower layer of the transverse mesocolon, is easily felt in the hollow 
between the vertebral column and the upper part of the descending colon. It is 
overlapped by coils. of small intestine, and passing transversely outwards in front 
of it 1s the left colic artery and its branches. Crossing the left kidney, a little 
above its middle, is the body of the pancreas, together with the splenic vessels. 
To reach the part of the kidney which lies above the pancreas, an opening should 
be made through the gastro-colic omentum and the hand passed upwards behind 
the stomach into the lesser sac of the peritoneum. Appled to the upper half or 
more of the outer border of the kidney is the renal surface of the spleen. 
The posterior relations of the kidneys have been referred to when dealing with 
the back. 
Outside the true capsule of the kidney is the adipose capsule, which is a 
specialised thickening of the extra-peritoneal fat. It is in this fat that a peri- 
nephritic abscess develops, the pus passing backwards into the lom, downwards 
towards the iliac fossa, or forwards into the extra-peritoneal fat of the anterior 
abdominal wall. 
The ureters lie behind the peritoneum covermg the psoas muscles; they 
descend almost vertically in the umbilical region 1} in. from the mesial plane. 
At the level of the intertubercular plane they lie in front of the termination of 
the common iliac arteries, and then pass down into the true pelvis in front of the 
internal iliac arteries. 
Pancreas.—The head of the pancreas occupies the curve of the duodenum, 
and lies in the lowest part of the right half of the epigastric region, on a level with 
the second lumbar vertebra. The neck, which crosses the mesial plane opposite the 
‘disc between the first and second lumbar vertebree, lies in the transpyloric plane, 
while the body lies immediately above that plane. The ¢ai les in the left hypo- 
chondriac region. The relations of the pancreas to the transverse mesocolon and 
to the neighbouring viscera have already been sufficiently referred to. 
A pancreatic cyst gives rise to a tumefaction of the abdomen either in the 
epigastric or in the umbilical region, depending on whether it pushes the gastro- 
hepatic omentum before it and develops between the liver and stomach, or whether 
it extends forwards below the stomach. In severe contusions of the abdomen the 
pancreas may be ruptured against the vertebral column. 
Vessels of the Abdomen.—The commencement of the abdominal aorta and the 
celiac axis is situated two fingers’ breadth above the transpyloric plane. The 
superior mesenteric artery arises a finger’s breadth above the transpyloric plane, the 
renal arteries a finger’s breadth below it. The inferior mesenteric artery arises mid- 
way between the transpyloric and the intertubercular plane—that is to say, about 
1 in. above the level of the umbilicus. The abdominal aorta bifurcates in, or ¢ 
little to the left of, the mesial plane, on a level with the highest part of the iliac 
crest, and about 3? in. below the level of the umbilicus. ‘ 
The inferior vena cava lies immediately to the right of the aorta; its most 
important surgical relation is the right ureter, which lies close to its outer side. 
The common and external iliac arteries may be mapped out by drawing a line, 
curved slightly outwards, from a point opposite the bifurcation of the aorta to a 
point midway between the anterior superior iliac spine and the pubic symphysis: 
the upper third of this line corresponds to the common iliac, the lower two-thirds 
to the external iliac. The common iliac veins lie mainly to the right of the corre- 
sponding arteries, the left vein, however, crossing behind the right artery to join its 
fellow to form the inferior vena cava. The relation of the veins and of the ureters 
must be borne in mind in ligaturing the common iliac arteries. 
