Peritoneum

Question 1

What is the peritoneum?

Answer 1

• a smooth membrane which lines the abdominal cavity

- similar to the pleura and pericardium in its arrangement

Question 2

What are the layers of the peritoneum?

Answer 2

• Parietal peritoneum: lines the abdominal walls
• Visceral peritoneum: covers abdominal organs
• Peritoneal cavity: a potential space between the parietal and visceral peritoneum; it is empty except for a thin film of serous fluid

Question 3

What is the difference in the peritoneal cavity between males and females?

Answer 3

• Males: completely closed sac
• Females: it communicates with the exterior through the uterine tubes; infections of the vagina can spread to the peritoneal cavity via this route

Question 4

What people are at risk for peritoneal infection via vaginal infection?

Answer 4

• immunocompromised patients

- unsanitary conditions during parturition

Question 5

What is the test for patency of the uterine tubes?

Answer 5

• dye introduced into the uterus normally enters the uterine tubes and then the peritoneal cavity
• if it does not, there is an obstruction
• done in fertility clinics

Question 6

What are the functions of the peritoneum?

Answer 6

• to minimize friction between organs: during peristalsis, trunk movement
• to resist infection: some parts act as a specialized immune organ
• fat storage: greater omentum

Question 7

What are retroperitoneal organs?

Answer 7

• lie posterior to the peritoneum and are covered by peritoneum only on their anterior surface
• examples: kidneys, suprarenal gland, aorta, inferior vena cava
• duodenum and pancreas are mostly retroperitoneal

Question 8

What is ascites?

Answer 8

• The accumulation of fluid within the peritoneal cavity.
• Represents an imbalance between fluid production and absorption. Several liters of fluid may accumulate.
• In a health person, peritoneum is highly absorbent.
• Causes:
  1. malnutrition
  2. congestive heart failure
  3. liver failure
  4. kidney failure
  5. peritonitis

Question 9

What is the peritoneal cavity used for?

Answer 9

• rabies vaccine

- kidney dialysis

Question 10

What is peritonitis?

Answer 10

• Inflammation of the peritoneum. Usually results from infection
• Causes:
  1. trauma
  2. inflammatory bowel disease (including ruptured appendix)
  3. vaginal infections
  4. perforated ulcers
• peritonitis often results in adhesions between the parietal and visceral peritoneum.
• adhesions are also caused by abdominal surgery, and may lead to bowel obstruction

Question 11

What is the innervation of the parietal peritoneum?

Answer 11

• Nerves of the adjacent body wall:
  1. Phrenic nerve
  2. Intercostal nerves
  3. Subcostal nerve
  4. Iliohypogastric nerve
  5. Ilioinguinal nerve
• Very sensitive to pain

Question 12

What is the innervation of the visceral peritoneum?

Answer 12

• Supplied by autonomic nerves which travel within the organs it invests
• Insensitive to pain

Question 13

What is an omentum?

Answer 13

a broad, apronlike reflection of peritoneum

Question 14

Describe the greater omentum.

Answer 14

• a large apronlike structure which hangs from the greater curvature of the stomach, covering abdominal viscera
• reflects posteriorly to attach to the transverse colon and transverse mesocolon
• has three parts:
  1. gastrophrenic ligament: between greater curvature of stomach and diaphragm
  2. gastrosplenic ligament: between greater curvature of stomach and spleen
  3. gastrocolic ligament: between greater curvature of stomach and transverse colon
• very mobile and often adheres to areas of inflammation, wrapping itself around inflamed organs and restricting the spread of infections - abdominal policeman

Question 15

Describe the lesser omentum.

Answer 15

• a double layer of peritoneum which extends from the porta hepatis (hilum) of the liver to the lesser curvature of the stomach and the beginning of the duodenum
• consists of two parts:
  1. hepatogastric ligament: between the liver and the lesser curvature of the stomach
  2. hepatoduodenal ligament: between the liver and the duodenum

Question 16

What do peritoneal ligaments do?

Answer 16

connect organs to one another or to the body wall

Question 17

What is the definition of mesentery (general)?

Answer 17

any double layer of peritoneum which connects a portion of intestine to the body wall

Question 18

What is the definition of mesentery (specific)?

Answer 18

• the double layer of peritoneum which connects the jejunum and ileum to the body wall
• sometimes referred to as the “mesentery proper”

Question 19

Describe the mesentery (of the jejunum and ileum).

Answer 19

suspends the jejunum and ileum from the posterior body wall and transmits the nerves and vessels which supply them

Question 20

Describe the transverse mesocolon.

Answer 20

connects the transverse colon to the posterior body wall

Question 21

Describe the sigmoid mesocolon.

Answer 21

• connects the sigmoid colon to the pelvic wall

Question 22

Describe the mesoappendix.

Answer 22

connects the appendix to the mesentery of the ileum

Question 23

Describe the phrenicocolic ligament.

Answer 23

• attaches the left colic flexure to the diaphragm, below the spleen
• suspends the left colic flexure in a more superior position than the right colic flexure

Question 24

What are the subdivisions of the peritoneal cavity?

Answer 24

• omental bursa (lesser sac)

- greater sac

Question 25

Describe the omental bursa (lesser sac).

Answer 25

- an irregularly shaped space which lies posterior to the liver, lesser omentum, and stomach - it is a closed sac except for its opening into the greater sac through the omental foramen

Question 26

Describe the greater sac.

Answer 26

extends from the diaphragm to the pelvic floor and across the entire breadth of the abdominal cavity

Question 27

What are the subdivisions of the greater sac?

Answer 27

- right subphrenic space (recess) - left subphrenic space (recess) - subhepatic space (recess) + hepatorenal recess - right paracolic gutter - left paracolic gutter

Question 28

Describe the right subphrenic space (recess).

Answer 28

located below the diaphragm and above the liver, to the right of the falciform ligament

Question 29

Describe the left subphrenic space (recess).

Answer 29

located below the diaphragm and above the liver, to the left of the falciform ligament

Question 30

Describe the subhepatic space (recess).

Answer 30

between the liver and the transverse colon

Question 31

Describe the hepatorenal recess.

Answer 31

posterosuperior extension of the subhepatic space, between the liver and right kidney

Question 32

Describe the right paracolic gutter.

Answer 32

a longitudinal depression lateral to the ascending colon

Question 33

Describe the left paracolic gutter.

Answer 33

a longitudinal depression lateral to the descending colon

Question 34

What is clinically important about the subdivisions of the greater sac?

Answer 34

they channel and compartmentalize peritoneal fluid and infectious processes

Question 35

What is a perforated duodenal ulcer?

Answer 35

- fluid enters the subhepatic recess - then to the right paracolic gutter - accumulates in the right iliac fossa - leads to peritonitis - often leads to appendicitis

Question 36

What is the omental foramen?

Answer 36

the opening between the omental bursa and greater sac

Question 37

What are the boundaries of the omental foramen?

Answer 37

- liver (superiorly) - first part of the duodenum (inferiorly) - free edge of the lesser omentum (anteriorly) - peritoneum covering the inferior vena cava (posteriorly)

Question 38

Which structures pass through the porta hepatis and are surrounded by the lesser omentum?

Answer 38

- bile duct (to the right and anterior) - hepatic artery proper (to the left and anterior) - portal vein (behind the other two structures and anterior to the omental foramen)