Digestive System—
Anatomy of the Pancreas, Liver, and the Biliary Tree
Lecture 16
Today we’re going to continue on our way down the gastrointestinal
tract and what we’re going to do is focus on those out pouchings that
I mentioned that occur during embryology and then develop into the
Lecture 16: Digestive System—Anatomy of the Pancreas, Liver, and the Biliary Tree
liver, the pancreas, and what we call the biliary tree, which is the inside
of the liver.
T
his lecture examines the anatomy of the pancreas, liver, and
gallbladder. First, we examine the gross and microscopic anatomy
of the pancreas, a 12-inch-long organ that produces hormones and
digestive juices and secretes them into the duodenum. We turn next to the
liver, the body’s largest and heaviest gland, and its second-largest organ (after
the skin). The location, size, and blood supply and routing of the liver are
reviewed. Finally, the lecture examines the gallbladder and biliary tree—the
complicated duct system that drains bile from the liver into the gallbladder
and the duodenum.
The peritoneal cavity is the abdominal space containing the intestines,
stomach, and liver. The peritoneal cavity is lined with a parietal peritoneum,
and the organs inside the cavity are covered with a visceral peritoneum,
as in the pleura and the pericardium. Retroperitoneal organs lie within the
peritoneal cavity but outside (behind) the visceral peritoneum. The pancreas,
the kidneys, the middle of the duodenum, and the rectum are important
examples.
The pancreas
Pancreas means “all esh,” which refers to its ability to digest virtually all
proteins, including itself. It is a retroperitoneal organ located in the posterior
part of the middle to upper abdominal cavity. It is about 12 inches long,
tapering from right to left. The head lies to the right, nestled in the duodenal
sweep. The body traverses up and to the left, tapering to the tail. The tail
terminates at the junction with the spleen.
92
, The posterior wall of the stomach lies against the anterior surface of the
pancreas. This is an important clinical relationship for cases of pseudocysts of
the pancreas. The rst portion of the duodenum lies in front of the pancreas.
This is important in complications of duodenal ulcer disease.
The pancreas is richly supplied with arteries and veins. It is served by branches
from the hepatic artery, the gastroduodenal artery, the pancreaticoduodenal
artery, the superior mesenteric artery, and the splenic artery.
A duct system drains bile into the duodenum. There is a major pancreatic
duct (the duct of Wirsung) and an accessory pancreatic duct (the duct of
Santorini). The ducts
meet at the right side
to empty through the
ampulla of Vater into the
duodenum. The main duct
usually joins the common
bile duct before entering
the duodenum. This
is important clinically
in common channel
pancreatitis.
© Hemera/ Thinkstock.
Exocrine and endocrine
functions coexist in
the pancreas. Endocrine
organs secrete hormones The biliary system, which is the endocrine
directly into the component of the digestive system.
bloodstream, while
exocrine organs secrete hormones directly into the lumen (cavity) of another
organ. The endocrine pancreas secretes hormones into the bloodstream.
The exocrine pancreas comprises 99% of pancreatic tissue. It secretes
digestive juices into the duct system and into the duodenum. Secretory cells
are arranged in acini around small ducts and secrete pancreatic juice into
progressively larger ducts.
93
Anatomy of the Pancreas, Liver, and the Biliary Tree
Lecture 16
Today we’re going to continue on our way down the gastrointestinal
tract and what we’re going to do is focus on those out pouchings that
I mentioned that occur during embryology and then develop into the
Lecture 16: Digestive System—Anatomy of the Pancreas, Liver, and the Biliary Tree
liver, the pancreas, and what we call the biliary tree, which is the inside
of the liver.
T
his lecture examines the anatomy of the pancreas, liver, and
gallbladder. First, we examine the gross and microscopic anatomy
of the pancreas, a 12-inch-long organ that produces hormones and
digestive juices and secretes them into the duodenum. We turn next to the
liver, the body’s largest and heaviest gland, and its second-largest organ (after
the skin). The location, size, and blood supply and routing of the liver are
reviewed. Finally, the lecture examines the gallbladder and biliary tree—the
complicated duct system that drains bile from the liver into the gallbladder
and the duodenum.
The peritoneal cavity is the abdominal space containing the intestines,
stomach, and liver. The peritoneal cavity is lined with a parietal peritoneum,
and the organs inside the cavity are covered with a visceral peritoneum,
as in the pleura and the pericardium. Retroperitoneal organs lie within the
peritoneal cavity but outside (behind) the visceral peritoneum. The pancreas,
the kidneys, the middle of the duodenum, and the rectum are important
examples.
The pancreas
Pancreas means “all esh,” which refers to its ability to digest virtually all
proteins, including itself. It is a retroperitoneal organ located in the posterior
part of the middle to upper abdominal cavity. It is about 12 inches long,
tapering from right to left. The head lies to the right, nestled in the duodenal
sweep. The body traverses up and to the left, tapering to the tail. The tail
terminates at the junction with the spleen.
92
, The posterior wall of the stomach lies against the anterior surface of the
pancreas. This is an important clinical relationship for cases of pseudocysts of
the pancreas. The rst portion of the duodenum lies in front of the pancreas.
This is important in complications of duodenal ulcer disease.
The pancreas is richly supplied with arteries and veins. It is served by branches
from the hepatic artery, the gastroduodenal artery, the pancreaticoduodenal
artery, the superior mesenteric artery, and the splenic artery.
A duct system drains bile into the duodenum. There is a major pancreatic
duct (the duct of Wirsung) and an accessory pancreatic duct (the duct of
Santorini). The ducts
meet at the right side
to empty through the
ampulla of Vater into the
duodenum. The main duct
usually joins the common
bile duct before entering
the duodenum. This
is important clinically
in common channel
pancreatitis.
© Hemera/ Thinkstock.
Exocrine and endocrine
functions coexist in
the pancreas. Endocrine
organs secrete hormones The biliary system, which is the endocrine
directly into the component of the digestive system.
bloodstream, while
exocrine organs secrete hormones directly into the lumen (cavity) of another
organ. The endocrine pancreas secretes hormones into the bloodstream.
The exocrine pancreas comprises 99% of pancreatic tissue. It secretes
digestive juices into the duct system and into the duodenum. Secretory cells
are arranged in acini around small ducts and secrete pancreatic juice into
progressively larger ducts.
93
