Unit 2: Lecture 2 Part 1 (Peritoneum)

Abdominal cavity

What body cavity contains digestive organs (stomach, intestines, liver, pancreas), urogenital organs (in part, including kidneys and ureters), and peritoneal and retroperitoneal structures?

Pelvic cavity

What body cavity contains distal digestive tract structures (rectum), reproductive organs (uterus, ovaries, prostate, seminal vesicles), and urinary bladder and urethra?

Pelvic diaphragm

What plays a key role in continence and pelvic organ support? Dysfunction is commonly implicated in pelvic organ prolapse and incontinence, particularly

postpartum.

Pericardial cavity, pleural, and peritoneal

What are the three major serous cavities in the body, each lined with a serous membrane that produces lubricating fluid?

Peritoneum

What is the serous membrane that lines the abdominal cavity and covers the abdominal

organs? It produces a small amount (~50 mL) of peritoneal fluid in healthy states for friction

reduction and organ mobility.

Pelvic cavity

What begins at the plane of the superior pelvic aperture (inlet) and is bounded inferiorly by the pelvic diaphragm?

Sacral promontory

What level is the superior pelvic aperture (inlet), where the pelvic cavity begins, at?

Parietal peritoneum

What lines the internal surface of the abdominal wall?

Visceral peritoneum

What covers the external surfaces of most abdominal organs?

Parietal and visceral peritoneum

Together, what two structures define the peritoneal cavity, which is normally a potential space? In disease states (e.g., ascites), fluid accumulation can reach up to 0.5-35 liters.

True

(T/F) Excess peritoneal fluid, or ascites, is a hallmark of several pathologies,

including cirrhosis and peritoneal carcinomatosis. It is detectable via imaging or percussion techniques.

Mesenteries

What are double layers of peritoneum that provide support and mobility to intraperitoneal organs while allowing a conduit for neurovascular structures?

Mesenteries

What structure performs the following:

• Suspend and anchor organs to the posterior abdominal wall

• Transmit blood vessels, lymphatics, and nerves between organ and body wall

• Allow limited mobility while maintaining structural organization

Mesenteries

Surgical approaches to the GI tract often involve navigating the ________ to

preserve vascular supply and minimize nerve damage.

2

How many layers make up the peritoneum?

Greater omentum, lesser omentum, mesentery proper, mesocolon

What are the 4 distinct mesenteries?

False

(T/F) The posterior part of the peritoneum lines the posterior abdominal wall.

Greater omentum

Which distinct mesentery is described:

• A large, apron-like fold of visceral peritoneum.

• Attaches the greater curvature of the stomach primarily to the transverse colon.

• Drapes over intestines and is rich in fat, lymphatics, and vasculature.

• Subdivided into peritoneal "ligaments":

• Gastrophrenic ligament - stomach to diaphragm

• Gastrosplenic ligament - stomach to spleen

• Gastrocolic ligament - stomach to transverse colon

False

(T/F) There is a space between the parietal and visceral peritoneum in a non-diseased state.

Greater omentum

What is often referred to as the "policeman of the abdomen" due to its ability to migrate to and contain sites of inflammation or infection, such as in appendicitis?

Lesser omentum

Which distinct mesentery is described:

• Connects the lesser curvature of the stomach and first part of the duodenum to the liver.

• Contains two key "ligaments":

• Hepatogastric ligament - stomach to liver

•Hepatoduodenal ligament - liver to duodenum; contains portal triad (hepatic artery, portal vein, bile duct)

Hepatoduodenal ligament

What ligament is clamped during the Pringle maneuver in liver surgery to control hepatic bleeding?

Mesentery proper

Which distinct mesentery is described:

• Connects the small intestine (jejunum and ileum) to the posterior abdominal wall.

• Fan-shaped, extends obliquely from the left upper quadrant (LUQ) to the right lower quadrant (RLQ).

• Contains superior mesenteric vessels, lymph nodes, and autonomic nerves.

Mesocolon

Which distinct mesentery is described:

• Attaches various regions of the large intestine to the posterior abdominal wall.

• Includes:

• Transverse mesocolon - connects transverse colon to posterior wall

• Sigmoid mesocolon - connects sigmoid colon to posterior wall

• Contains branches of the inferior and superior mesenteric arteries, lymphatics, and nerves.

Ascites

What is excess peritoneal fluid referred as?

True

(T/F) The greater and lesser omenta are derived from embryologic mesenteries and play active roles in immune surveillance.

Greater sac

What is the larger of the two peritoneal sacs that comprises the major portion of the peritoneal cavity?

Greater sac and lesser sac (Omental bursa)Wdd

What are the two peritoneal sacs?

Supracolic and infracolic compartments

What are the two subdivisions of the greater sac?

Supracolic compartment

Which subdivision of the greater sac lies above the transverse colon, contains the stomach, liver, and spleen?

Infracolic sac

Which subdivision of the greater sac lies below the transverse colon, contains the small intestines and ascending/descending colon?

Transverse mesocolon

What separates the two compartments of the greater sac?

Lesser sac (Omental bursa)

Which peritoneal sac is a smaller cavity located posterior to the stomach and lesser omentum that is created by the folding of the greater and lesser omenta and allows free movement of the stomach and associated viscera?

Which peritoneal sac communicates with the greater sac via the epiploic (omental) foramen?

Epiploic (omental) foramen

What is the only natural opening between the greater and lesser sacs?

Lesser sac

Pancreatic fluid collections or abscesses can accumulate in the ____ ____, particularly in pancreatitis or post-surgical scenarios.

Epoploic foramen

Internal herniation through the _____ _____ is rare but potentially life-threatening due to vascular compression. Recognizing its anatomy is essential during surgical exploration.

Peritoneal ligaments

What are double layers of peritoneum that serve as connections between organs

or between organs and the abdominal wall? In the case of the liver, these ligaments stabilize its position in the upper abdomen and demarcate functional or anatomical subdivisions.

Hepatogastric and hepatoduodenal ligaments

What are the two key ligaments of the lesser omentum?

Hepatoduodenal ligmanet

What ligament of the lesser omentum contains the portal triad (hepatic artery, portal vein, bile duct)?

Gastrophrenic, gastrosplenic, and gastrocolic ligaments

What are the 3 peritoneal ligaments of the greater omentum?

Gastrocolic ligament

What ligament connects the stomach to the transverse colon?

Gastrosplenic ligament

What ligament connects the stomach to the spleen?

Gastrophrenic ligament

What ligament connects the stomach to the diaphragm?

Greater omentum

What structure will plug a hole if there is a puncture of the abdominal wall?

Falciform, coronary, and triangular ligaments

What are the 3 key peritoneal ligaments of the liver?

Falciform ligament

What ligament of the liver:

• Connects the anterior surface of the liver to the anterior abdominal wall.

• Contains the ligamentum teres hepatis (round ligament of the liver)—a remnant of the fetal umbilical vein.

• Acts as a superficial marker between the right and left lobes of the liver.

Falciform ligament

What ligament can be a surgical landmark and is also used to orient laparoscopic approaches to the upper abdomen?

Coronary ligament

What ligament of the liver:

• Connects the superior surface of the liver to the inferior surface of the diaphragm.

• Consists of anterior and posterior layers of peritoneum.

• Demarcates the bare area of the liver, where the liver is in direct contact with the diaphragm and lacks peritoneal covering.

Bare area

What is a potential pathway for the spread of infection or metastasis between the liver and thoracic structures?

Triangular ligaments

What ligament of the liver:

• Formed by the convergence of the anterior and posterior layers of the coronary ligament.

• Right triangular ligament - at the right edge of the liver

• Left triangular ligament - at the left edge of the liver

Triangular ligaments

What ligaments further anchor the liver to the diaphragm and define lateral extremes of the

coronary ligament?

Intraperitoneal organs

What organs are completely surrounded by visceral peritoneum and suspended within the

peritoneal cavity by mesenteries? This configuration allows for mobility and vascular access.

Stomach, spleen, jejunum and ileum (small intestine), cecum and appendix, transverse colon, and sigmoid colon

What are the key intraperitoneal organs?

Intraperitoneal organs

What organs are more prone to generalized peritonitis following perforation due to their exposure to peritoneal fluid and free communication with the peritoneal?

True

(T/F) All organs within the peritoneum has a mesocolon.

Retroperitoneal organs

What organs lie against the posterior abdominal wall and are only partially covered—anteriorly—by parietal peritoneum? They do not have mesenteries and are relatively fixed in position.

Kidneys, pancreas, abdominal aorta, inferior vena cava, adrenal glands, ureters, ascending and descending colon, and rectum

What are the key retroperitoneal organs?

True

(T/F) Retroperitoneal bleeding, such as from a ruptured abdominal aortic aneurysm or renal trauma, may be masked on initial physical examination due to deep location.

Intraperitoneal organs

Which group of organs are more mobile?

Hepatoduodenal ligament (containing the portal triad)

What is the anterior border of the epiploic (omental) foramen?

Inferior vena cava

What is the posterior border of the epiploic (omental) foramen?

Caudate lobe of liver

What is the superior border of the epiploic (omental) foramen?

First part of duodenum

What is the inferior border of the epiploic (omental) foramen?

Ligamentum teres hepatis (round ligament of the liver)

What structure found within the falciform ligament is a remnant of the fetal umbilical vein?

Bare area

What part of the liver has no peritoneum on it?

True

(T/F) Nearly all anterior organs are intraperitoneal.

Intraperitoneal organs

What group of organs are completely covered by visceral and parietal peritoneum?

True

(T/F) The vast majority of duodenum is retroperitoneal.

(T/F) The jejunum and ileum are completely intraperitoneal.

Ascending and descending colon and rectum

What are the only parts of the large intestine that are not intraperitoneal, making them retroperitoneal?