ANATOMY: PART II

Q: What is the parietal peritoneum?

A: A membrane that lines the inner wall of the abdominal cavity.

Q: What is the visceral peritoneum?

A: A membrane that covers the outer surface of many abdominal organs.

Q: What is the peritoneal cavity?

A: The potential space between the parietal and visceral peritoneum, containing a small amount of lubricating fluid.

Parietal = wall
Visceral = viscera/organs

Q: What does intraperitoneal mean?

A: An organ that is almost completely covered by visceral peritoneum and generally suspended in the peritoneal cavity by a mesentery.

Q: Give examples of intraperitoneal organs from your notes.

A: Stomach, liver, and jejunum.

Q: What does retroperitoneal mean?

A: An organ located behind the peritoneum.

Q: Give examples of retroperitoneal structures from your notes.

A: Kidneys, pancreas (mostly), duodenum (mostly), and ascending/descending colon.

Q: What is the major distinction between intraperitoneal and retroperitoneal organs?

A: Intraperitoneal organs are generally suspended within the peritoneal cavity and covered by visceral peritoneum, whereas retroperitoneal organs lie behind the peritoneum.

Q: What are peritoneal formations?

A: Folds or structures made of peritoneum that support, connect, and organize abdominal organs.

Q: What is a mesentery?

A: A double layer of peritoneum connecting an organ to the posterior abdominal wall.

Q: What travels within a mesentery?

A: Blood vessels, nerves, and lymphatics.

Q: What is an omentum?

A: A fold of peritoneum that hangs from or connects abdominal organs and may contain fat, blood vessels, and lymphatics.

Q: What is the greater omentum?

A: Hangs from the greater curvature of the stomach and covers the intestines.

Q: What is the lesser omentum?

A: Connects the stomach and duodenum to the liver.

Q: What is a peritoneal ligament?

A: A fold/double layer of peritoneum connecting an organ to another organ or to the abdominal wall.

: Give an example of a peritoneal ligament.

A: The falciform ligament, which connects the liver to the anterior abdominal wall.

Q: How do you distinguish mesentery, omentum, and ligament?

A:

• Mesentery → supports organ + carries vessels/nerves/lymphatics

• Omentum → hangs over/covers organs + contains fat

• Ligament → connects organs or organ to body wall

Q: What does the gastrohepatic ligament connect?

A: Stomach → liver.

Q: What is the gastrohepatic ligament part of?

A: The lesser omentum.

Q: What does the hepatoduodenal ligament connect?

A: Liver → duodenum.

Q: What important structures are found in the hepatoduodenal ligament?

A: The portal triad.

Q: What does the gastrophrenic ligament connect?

A: Stomach → diaphragm.

Q: What does the gastrosplenic ligament connect?

A: Stomach → spleen.

Q: What vessels are found in the gastrosplenic ligament?

A: Short gastric and left gastro-omental vessels.

Q: What does the transverse mesocolon connect?

A: Blood vessels, nerves, and lymphatics supplying the transverse colon.

Q: What does the gastrocolic ligament connect?

A: Stomach → transverse colon.

Q: What is the gastrocolic ligament part of?

A: Greater omentum.

💡 Memorize the names literally:

Gastrohepatic = gastro + hepatic → stomach ↔ liver
Hepatoduodenal = liver ↔ duodenum
Gastrophrenic = stomach ↔ diaphragm
Gastrosplenic = stomach ↔ spleen
Gastrocolic = stomach ↔ colon

Q: Where is the portal triad located?

A: In the hepatoduodenal ligament.

Q: What are the three components of the portal triad?

A:

1. Proper hepatic artery

2. Hepatic portal vein

3. Common bile duct

Q: What does the proper hepatic artery carry?

A: Oxygenated blood to the liver.

Q: What does the hepatic portal vein carry?

A: Nutrient-rich blood from the GI tract to the liver.

Q: What does the common bile duct carry?

A: Bile toward the duodenum.

💡 Memory:
A-V-D

Artery
Vein
Duct

Q: What is the role of the lesser omentum in the peritoneal cavity?

A: It lies between the liver and stomach/duodenum and forms the anterior boundary of the lesser sac.

Q: What does the transverse mesocolon do?

A: Acts as a horizontal divider between the supracolic compartment above and infracolic compartment below.

Q: What does the small-intestine mesentery do?

A: Connects the small intestine to the posterior abdominal wall and helps divide the infracolic compartment into right and left spaces.

Q: What does the greater omentum do?

A: Hangs from the greater curvature of the stomach, drapes over the intestines, contains substantial fat, and can help contain inflammation.

Q: What are the paracolic gutters?

A: Vertical spaces along the sides of the ascending and descending colon that allow fluid to move between abdominal regions.

Q: Why are the paracolic gutters clinically important?

A: Blood, infection, fluid, or other material in the peritoneal cavity can move along them.

Q: What is the omental foramen?

A: A natural opening connecting the greater sac and lesser sac.

Q: What is another name for the omental foramen?

A: Epiploic foramen.

Q: What is the greater sac?

A: The main/larger portion of the peritoneal cavity.

Q: What is the lesser sac/omental bursa?

A: A smaller peritoneal space located behind the stomach.

Q: What forms the anterior boundary of the omental foramen?

A: Hepatoduodenal ligament.

Q: What is contained within the hepatoduodenal ligament?

A: Portal triad.

Q: What is the Pringle maneuver?

A: Compression of the hepatoduodenal ligament to temporarily reduce blood flow entering the liver.

Q: Why would a surgeon perform a Pringle maneuver?

A: To help control hepatic bleeding during surgery.

Q: What two major blood vessels are compressed during the Pringle maneuver?

A:

• Proper hepatic artery

• Hepatic portal vein

Q: Where can a surgeon place a finger to perform the Pringle maneuver?

A: Through the omental foramen to compress the hepatoduodenal ligament.

Pringle = pinch the portal triad

Q: What two planes divide the abdomen into four quadrants?

A:

• Median plane

• Transumbilical plane

Q: What are the four abdominal quadrants?

A:

• RUQ = Right upper quadrant

• LUQ = Left upper quadrant

• RLQ = Right lower quadrant

• LLQ = Left lower quadrant

Q: What structures are derived from the foregut according to your notes?

• Esophagus

• Stomach

• Proximal duodenum

• Liver

• Gallbladder

• Pancreas

Q: What structures are derived from the midgut?

A:

• Distal duodenum

• Jejunum

• Ileum

• Cecum

• Appendix

• Ascending colon

• Proximal ⅔ of transverse colon

Q: What structures are derived from the hindgut?

A:

• Distal ⅓ of transverse colon

• Descending colon

• Sigmoid colon

• Rectum

• Proximal anus

Q: Which portion of the transverse colon is midgut?

A: Proximal 2/3.

Q: Which portion is hindgut?

A: Distal 1/3.

Q: What are the major regions of the stomach?

• Cardia

• Fundus

• Body

• Pyloric canal

Q: What are the two major curvatures of the stomach?

A: Lesser curvature and greater curvature.

Q: What is the esophagogastric junction?

A: The junction where the esophagus meets the stomach.

Q: What is the Z-line?

A: The visible boundary where the lining changes from esophageal epithelium to gastric epithelium.

Q: What is the duodenum?

A: The first part of the small intestine.

: What is the shape of the duodenum?

A: C-shaped

Q: What structure sits within the C-shaped curve of the duodenum?

A: Head of the pancreas.

Q: What are the four parts of the duodenum?

A:

1. Superior

2. Descending

3. Horizontal/inferior

4. Ascending

Q: What is special about the superior/first part of the duodenum?

A: It begins immediately after the stomach and is mostly intraperitoneal.

Q: What is the proximal portion of the first part called?

A: Duodenal bulb.

Q: What is special about the descending/second part?

A: It is mostly retroperitoneal and contains the major duodenal papilla.

Q: What enters the descending duodenum at the major duodenal papilla?

A: Bile and pancreatic secretions.

Q: What is special about the horizontal/third part?

A: It runs right → left and is retroperitoneal.

Q: What major structures does the third part pass across?

A: Front of the aorta and IVC.

Q: What is special about the ascending/fourth part?

A: It runs upward, is mostly retroperitoneal, and ends at the duodenojejunal flexure.

Q: Which part of the duodenum is mostly intraperitoneal?

A: First/superior part.

Q: Which parts are mostly retroperitoneal?

A: Second, third, and fourth.

Q: Which part contains the major duodenal papilla?

A: Second/descending part.

Q: Where do bile and pancreatic secretions enter?

A: Major duodenal papilla

Q: Where is the pancreas located?

A: Behind the stomach, extending from the duodenum toward the spleen

Q: What are the major parts of the pancreas?

A:

• Head

• Uncinate process

• Neck

• Body

• Tail

Q: Where is the head of the pancreas located?

A: Within the C-shaped curve of the duodenum.

Q: What is the largest part of the pancreas?

A: Head.

Q: What is the uncinate process?

A: A hook-like extension of the pancreatic head that extends posteriorly and wraps around/behind major vessels.

Q: What is the relationship of the pancreatic neck to the portal vein?

A: The neck is located anterior to the formation of the portal vein.

Q: Which direction does the pancreatic body extend?

A: Toward the left from the neck.

Q: Where does the tail of the pancreas extend?

A: Toward the spleen.

Q: What ligament contains the pancreatic tail?

A: Splenorenal ligament.

Q: Which major arterial systems supply the pancreas?

A: Branches of the celiac trunk and SMA.

Q: What arteries supply the pancreatic head?

A: Superior and inferior pancreaticoduodenal arteries.

Q: What is the origin of the superior pancreaticoduodenal arteries?

A: Gastroduodenal artery → celiac trunk.

Q: What is the origin of the inferior pancreaticoduodenal arteries?

A: Superior mesenteric artery.

Q: What artery supplies much of the pancreatic body and tail?

A: Splenic artery.

Head = pancreaticoduodenal arteries
Body/tail = splenic artery

Q: Where is the omental bursa relative to the stomach and pancreas?

A: Posterior to stomach and anterior to pancreas.

Q: What are the three major features used to distinguish jejunum from ileum?

A:

1. Mesenteric fat

2. Arterial arcades

3. Vasa recta

Q: How much fat does the jejunal mesentery contain?

A: Less fat.

Q: How many arterial arcades does the jejunum have?

A: Fewer.

Q: What are jejunal vasa recta like?

A: Longer.

Q: How much fat does the ileal mesentery contain?

A: More fat

Q: How many arterial arcades does the ileum have?

A: More.

Q: What are ileal vasa recta like?

A: Shorter.

Q: What is the pathway through the large intestine?

A:

Ileum → Ileocecal valve → Cecum → Ascending colon → Right colic flexure → Transverse colon → Left colic flexure → Descending colon → Sigmoid colon → Rectum → Anal canal

Q: What is the cecum?

A: First part of the large intestine; receives material from the ileum.

Q: What does the ileocecal valve do?

A: Controls passage from ileum → cecum and helps prevent backflow.