THE PERITONEUM. 1051 
from the upper surface of the empty bladder, and when well marked, passing to the neighbour- 
hood of the internal abdominal ring. 
Above the bladder, on each side of the urachus, is found the internal inguinal fossa already 
referred to (p. 1048). Both of these fossee are practically obliterated by distension of the 
bladder. 
Similarly, there is seen at each side of the empty rectum, on the posterior pelvic wall, a large 
depression, which may be known as the pararectal fossa (fossa pararectalis, Fig. 708). When the 
rectum is empty and contracted, these fosse are filled by intestine; during distension, the 
rectum increasing in width, expels the intestine and practically obliterates the fossze. 
Transverse Tracing of the Peritoneum.—If the peritoneum be followed trans- 
versely around the abdomen, just above the level of the iliac crest, where the com- 
plications produced 
by the small sae are Talcironnsusnese 
absent (Fig. 709, B), Foramen of Winslow poser rane eat) 
5 aren : : Stomach ; 
few difficulties will Rw, y 
be encountered. 
From the anterior eae 
abdominal wall it _ splenic 
passes round on each O™™t™? 
side to the back, 
lining the lateral and 
posterior walls. Pass- 
ing inwards on the 
posterior wall, it 
meets the colon— 
ascending on the 
right side, descend- 
Round ligament of liver 
Z N TI Sse 
. a >> 2 f fj AL == 
ing on the left—over RN SS g 
thie 1 1a AEE TG . : \ SAT ~ ie 
which it is carried, — yieno.renai Nc hy RCS WE fer 
in each case covering ligament Right kidney 
the bowel in front 
and at the sides only, 
and leaving the pos- 
terior surface bare, 
as a rule. Some- 
times, however, the , YN 
covering is complete, Md NG Mi) Z AW (cava 
and a short mesen- 
tery is formed. It 
is next continued 
inwards over the 
psoas muscles, the 
ureters, and the great \ aS A 
vessels, on the front WS 7] ee XQ) RNa] WAGs 
of which it meets the : ny 
superior mesenteric 
artery and vein run- 
ning downwards to Descending colon 
the intestines. From 
both sides it passes 
Small intestine Theo mesentery 
Ascending colon 
Fic. 709.—DIAGRAMMATIC TRANSVERSE SECTIONS OF ABDOMEN, to show the 
peritoneum on transverse tracing. A, at level of foramen of Winslow, 
forwards on these B, lower down. In A, note one of the vasa brevia arteries passing to 
vessels, forming the the stomach between the layers of the gastro-splenic omentum, and also 
: : a the foramen of Winslow leading into the lesser sac which lies behind the 
right and left layers SiereaTi! 
of the mesentery ; 
and finally, having reached the intestine, it clothes it completely, and the two 
portions become continuous on the bowel. 
A transverse tracing at a higher level would include the small sac; it will, 
therefore, be well to study this portion of the peritoneum before describing such a 
tracing. 
Small Sac of the Peritoneum (bursa omentalis)—This, as already pointed 
