The Dissection of Vertebrates A Laboratory Manual

Dissection
area
Falciform ligament
Central tendon
Liver, right lateral lobe
Liver, caudate lobe
Liver, right medial lobe
Abdominal wall lined
by visceral peritoneum
Lateral ligament,
filled with fat
FIGURE 7.46 Abdominopelvic cavity of the cat in ventral view, with diaphragm reflected.
Posterior to the stomach, the abdominal cavity is covered
ventrally by the omental bursa, a large, double-layered,
fat-laced mesentery that covers the intestines like an
apron (Figure 7.46). The bursa is a sac-like structure
formed from the greater omentum, which is part of the
dorsal mesentery. Its structure will be discussed shortly.
The omental bursa extends posteriorly to the urinary
bladder, the light-colored, median, sac-like organ lying
ventrally. If it is empty, it resembles a collapsed balloon.
The mesentery passing from the bladder to the midventral
wall, just to the left of the incision made to open the
abdominopelvic cavity, is the median ligament (Figure
7.46). The bladder is also supported by lateral ligaments,
one on either side, that are often filled by wads of fat.
Heart
Round ligament
Diaphragm
Liver, left medial lobe
Liver, quadate lobe
Liver, left lateral lobe
Stomach
Gallbladder
Visceral organs lined
by visceral peritoneum
Spleen
Small intestine
Omental bursa,
ventral sheet,
laced with fat
Urinary bladder
Median ligament
Return to the anterior part of the abdominal cavity
and spread apart the stomach and liver (Figure 7.48).
The mesentery extending from the lesser curvature
of the stomach and duodenum to the liver is the lesser
omentum (another example of ventral mesentery),
which is divided into two portions. One part, the
hepatogastric ligament, passes from the lesser curvature
to the liver. The other, passing from the proximal
part of the duodenum to the liver, is the hepatoduodenal
ligament, which appears to head toward the gall
bladder. Various structures pass through the lesser
omentum, including the common bile duct and
the hepatic artery. These will be considered
below.
SECTION IV—DIGESTIVE AND RESPIRATORY SYSTEMS 189