Nutrition and the Digestive System 407
LABORATORY
The Digestive System continued
EXERCISE:long flaplike structure called the spleen,
which is part of the lymphatic system and
whose function is blood storage. Our spleen is
more kidney bean shaped as opposed to the
long, flat spleen of the pig.^- Examine the duodenum of the small intes-tine
more closely. Observe how the liver and the
duodenum are connected by the bile duct.
Now lift the stomach and locate the pancreas,
a light-colored spongy gland. The pancreas
also has a duct that empties into the
duodenum. Note the parts of the pancreas: the
head, body, and tail. Observe that a large
amount of intestine in the pig is the small
intestine. At the distal end of the
small intestine, a blind sac, the cecum, can be
seen on the left side of the abdominal cavity
of the pig. It is found at the point of juncture
where the small intestine joins the large
intestine.^- From the cecum, follow the large intestine
(about double the diameter of the small
intestine), now known as the colon, as it
tightly coils to join the large dorsal rectum,
which ends at the anus. Before we complete
our dissection of the digestive tract of the
fetal pig, cut open a piece of the small in-
testine to observe the plicae. These are the
folds of the small intestine that increase the
absorptive capabilities of the intestine.