| THE PERITONEUM. 1053 
The transverse tracing at the level of the foramen of Winslow is shown in Fig. 
708, A, and ean be easily followed without any further description than is there 
given. 
The following additional details may be mentioned :—The small sac is divided by a constric- / 
tion into two parts—an upper, lying behind the lesser omentum and Spigelian lobe, and a lower, 
placed behind the stomach and within the great omentum. The constriction is due to the passage 
of the coronary and hepatic arteries forward around the sac; the former winds round its left 
side, the latter round its right ; and each raises up a fold of peritoneum, which projects strongly 
into the sac, and partially divides it into two. This can be shown by cutting the lesser omentum 
along the lesser curvature of the stomach and looking into the cavity. 
Where the small sac runs up behind the Spigelian lobe, it forms, as pointed out at page 1065, 
Top of small sac 
Inferior vena cava Left lateral ligament of liver 
Lesser omentum (cut) \ | Gisopnaeca! opening in diaphragm 
\ / Gastro-phrenic ligament 
| / / Corresponds to ‘uncovered area’ of stomach 
Fuphulateral feament | / / / Gastro-splenic omentum (cut) 
a) te / ‘ 
Phreno-colic ligament 
fatal \ 
. . / \ 
Transverse colon crossing duodenum = _/ / \ : 
Head of pancreas | Left end of transverse mesocolon 
yz a E 
| 
| 
\ | | | 
Great omentum (cut) \} Splenic flexure of colon 
| Transverse mesocolon (cut) 
Part of small sac 
Root of mesentery (cut) 
Fic. 710.-—THE PERITONEAL RELATIONS OF THE DUODENUM, PANCREAS, SPLEEN, KIDNEYS, ETC. 
the left boundary of the uncovered area of the right lobe, and, consequently, a third or left layer 
of the coronary ligament. 
A special diverticulum of the small sac runs out to the right, behind the beginning of the 
duodenum, to clothe the back of that tube for about an inch (Fig. 710). 
The splenic artery reaches the spleen by passing to the left, behind the posterior layer of the 
small sac, which also extends to that organ (Fig. 709, A). 
The lesser omentum is described at page 1066; it need only be pointed out 
now that it is composed of two layers, the anterior derived from the great sac, 
and the posterior from the small sae, both of which are extremely thin—some- 
times even cribriform. 
The great omentum is a large apron-like fold of peritoneum, usually more or 
less loaded with fat, which is suspended from the great curvature of the stomach, 
