Abdomen and Pelvis 
level of the transverse mesocolic root, the perito- 
neum sweeps cranially on the dorsal surface of the 
ventral abdominal wall relatively free of attach- 
ments until it passes across the visceral surface of 
the diaphragm, which it covers, to form the falci- 
form ligament (lig. falciforme hepatis), enclosing 
the ligamentum teres (lig. teres hepatis) and 
spreading between the left medial and quadrate 
lobes of the liver. The falciform ligament runs just 
under the xiphoid process caudally into the umbili- 
cal region. Cranially, the peritoneal sheets sepa- 
rate laterally from the falciform fold to form the left 
coronary ligament {lig. coronarium sinistrum 
hepatis), between the diaphragm and the upper 
margin of the left lateral lobe, and the right coro- 
nary ligament, between the diaphragm and the 
dorsal wall of the right medial lobe. The peritoneum 
then reflects from the liver to the diaphragmatic 
part of the dorsal abdominal wall as the left and 
right triangular ligaments {ligg. triangularia sinis- 
trum et dextrum). The right ligament reflects from 
the right lateral lobe and the left ligament from the 
left lateral lobe, and there is a bare area free of 
peritoneum between them. 
After investing the liver, the peritoneal sheet 
leaves the transverse fissure and passes to the 
stomach, forming the ventral layer of the lesser 
omentum {omentum minus). The cranial end of 
the lesser omentum extends from the left side of 
the liver to the lesser curvature of the glandular 
stomach as the hepatogastric ligament {lig. hepa- 
togastricum); the caudal end attaches the glandular 
stomach to the papillary process of the liver, to the 
right of which the hepatogastric ligament continues 
as the hepatoduodenal ligament {lig. hepatoduo- 
denale). 
The lesser omentum serves as part of the ventral 
wall of the lesser peritoneal cavity, or omental 
bursa {bursa omentalis), along with the caudate 
lobe of the liver in the cranial part and, in the dor- 
sal part, the stomach and the greater omentum 
{omentum majus). Through the lesser omentum 
there is a perforation, the epiploic foramen {fora- 
men epiploicum) which lies between the caudal 
vena cava and the portal vein and links the lesser 
with the greater peritoneal cavity. In effect, the 
edge of the lesser omentum, which spreads between 
the liver and the small intestine, borders the fora- 
men on the right side. The caudal limit of the lesser 
peritoneum consists of the cranial section of the 
greater omentum and the transverse colon, while 
the transverse mesocolon, ventral surface of the 
pancreas, left adrenal gland and cranial pole of the 
left kidney form the caudodorsal boundary. Since 
the lesser omentum extends obliquely in a cranio- 
dorsal-caudoventral plane, the dorsal abdominal 
wall serves as its dorsal boundary until the parietal 
peritoneum on the dorsal wall is interrupted by the 
coronary ligament under the diaphragm, thus clos- 
ing the sac. The visceral peritoneal layer is then 
reflected from the liver at the transverse fissure to 
the dorsal gastric surfaces, forming the dorsal layer 
of the hepatogastric ligament. From the greater 
curvature it passes caudally and then cranially to 
the transverse colon to form the dorsal layer of the 
greater omentum. From the dorsal margin of the 
transverse colon it runs as the cranial layer of the 
transverse mesocolon to the ventral surface of the 
pancreas. 
After covering the ventral wall of the glandular 
stomach, by reflecting from one margin of the lesser 
curvature to the greater curvature on the other 
side, the peritoneum leaves the greater curvature 
of the glandular stomach, forestomach and duode- 
num to form the ventral layer of the greater omen- 
tum. It then passes dorsal to the transverse colon, 
which it invests, to the vertebral column at the 
lower edge of the pancreas, before passing caudally 
to cover the distal duodenum and caudomesocolic 
structures. 
At its origin, the dorsal layer of the greater 
omentum forms adhesions with the transverse 
mesocolon in adult animals, settling between the 
stomach and ventral abdominal wall and extend- 
ing only slightly caudally to cover the intestines. 
Viewed in a transverse plane through the cranio- 
mesocolic viscera at the level of the epiploic fora- 
men and beginning at the ventral midline, the 
parietal peritoneum moves to the right kidney 
without interruption, except for the falciform liga- 
ment ventrally, along the ventral and lateral ab- 
dominal walls. After covering the visceral surface 
of the right kidney and forming the dorsal wall of 
the epiploic foramen, it covers the caudal vena cava, 
aorta, vertebral column and pancreas on the left 
side of the animal. The peritoneum then passes 
123 
