Peritoneum and Sacs

Question 1

Be aware of the various regional names of the continuous layer of fascia located between the peritoneum and overlying musculature.

Answer 1

The fascia that adheres the peritoneum to the abdominal wall varies in name for the region in which it is found. Fascia transversalis (anterolateral wall); diaphragmatic (diaphragm); quadratus lumborum (posterior wall); pelvic fascia (in pelvis) and fascia iliaca (portion that passes under the inguinal ligament into the femoral canal).

Question 2

What lies within this fascial layer?

Answer 2

Abdominal/pelvic blood and lymphatic vessels.

Question 3

What lies outside this fascial layer?

Answer 3

The nerves

Question 4

What is the peritoneum composed of?

Answer 4

A single cell layer of flattened epithelial (mesothelial) cells.

Question 5

What is the function of the peritoneum?

Answer 5

Provide friction-free movement of abdominal contents over one another as well as form ligaments and omenta etc. that suspend abdominal contents.

Question 6

What does the peritoneum secrete to facilitate this function?

Answer 6

A small amount of peritoneal fluid.

Question 7

How does parietal peritoneum differ from visceral peritoneum in location, sensitivity?

Answer 7

Parietal lines the body wall, visceral intimately covers the surface of all abdominal organs (except those that are retroperitoneal in location). The parietal peritoneum is highly sensitive, the visceral component is insensitive.

Question 8

How many layers of peritoneum are involved in each of the following: mesentery,
mesocolon, ligaments, and omentum. State one example of each.

Answer 8

Two layers in each: mesentery, ligament, lesser omentum,and mesocolon. The greater omentum is 4 layers (2 double layers). The hepatocolic ligament; the greater omentum, the sigmoid mesocolon, the small intestinal mesentery.

Question 9

Define the location of the lesser sac. What clinical importance

Answer 9

That space behind the stomach and below the liver. Surgical access to the pancreas lying behind

Question 10

What is the remaining space within the abdominal cavity referred to as?

Answer 10

The greater sac

Question 11

Do the two sacs communicate? If so through what and specifically where is this
communication located?

Answer 11

Yes, via the epiploic foramen (of Winslow) located just under the free edge of the lesser omentum (that contains the portal triad).

Question 12

Name the 5 peritoneal folds extending inferiorly from the umbilicus on the deep
surface of the anterior abdominal wall.

Answer 12

One median; two medial; and two lateral umbilical folds.

Question 13

What does each peritoneal fold contain?

Answer 13

The median umbilical fold contains the obliterated urachus; the medial umbilical folds contain the obliterated umblical artery; and the two lateral umbilical folds contain the inferior epigastric aa.

Question 14

Name the one peritoneal fold that passes superiorly.

Answer 14

The falciform ligament.

Question 15

What is in the free edge of this superior peritoneal fold?

Answer 15

The ligamentum teres.

Question 16

What was the structure found in this free edge during embryological development?

Answer 16

The umblical vein.

Question 17

Be able to identify the organs found in the supracolic compartment of the abdomen.

Answer 17

Last 1/2” of esophagus, stomach, 1st part of duodenum, liver, gallbladder and spleen.

Question 18

Where are the subhepatic and subphrenic spaces?

Answer 18

The subhepatic spaces are those found under the liver. The subphrenic spaces are those found under the diaphragm.

Question 19

Which of these is spaces is synonymous with the lesser sac?

Answer 19

The left subhepatic space.

Question 20

Why are these spaces/gutters clinically important?

Answer 20

Pus/infection from abcesses etc. can drain throughout the abdominopelvic cavity by flowing along these spaces/gutters as you sit up/lay down, etc.

Question 21

What is the function of the greater omentum?

Answer 21

It attempts to compartmentalize infection etc.

Question 22

Name the 3 component ligaments that fuse to form the greater omentum

Answer 22

Gastrocolic, gastrosplenic and gastrophrenic ligaments.

Question 23

Where does the lesser omentum extend?

Answer 23

From the underside of the liver to the lesser curvature of the stomach.

Question 24

How many ligaments fuse to form the lesser omentum? name them.

Answer 24

Two. The hepatogastric and hepatoduodenal ligaments.

Question 25

What structure can be found in the free edge of the lesser omentum?

Answer 25

The portal triad (common bile duct, hepatic portal v. and hepatic a.).

Question 26

What is located under the free edge of the lesser omentum?

Answer 26

The gastroepiploic foramen (of Winslow).