Peritoneum Flashcards
What is the peritoneum?
- a smooth membrane which lines the abdominal cavity
- similar to the pleura and pericardium in its arrangement
What are the layers of the peritoneum?
- 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
What is the difference in the peritoneal cavity between males and females?
- 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
What people are at risk for peritoneal infection via vaginal infection?
- immunocompromised patients
- unsanitary conditions during parturition
What is the test for patency of the uterine tubes?
- 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
What are the functions of the peritoneum?
- to minimize friction between organs: during peristalsis, trunk movement
- to resist infection: some parts act as a specialized immune organ
- fat storage: greater omentum
What are retroperitoneal organs?
- 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
What is ascites?
- 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
What is the peritoneal cavity used for?
- rabies vaccine
- kidney dialysis
What is peritonitis?
- 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
What is the innervation of the parietal peritoneum?
- 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
What is the innervation of the visceral peritoneum?
- Supplied by autonomic nerves which travel within the organs it invests
- Insensitive to pain
What is an omentum?
a broad, apronlike reflection of peritoneum
Describe the greater omentum.
- 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
Describe the lesser omentum.
- 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
What do peritoneal ligaments do?
connect organs to one another or to the body wall
What is the definition of mesentery (general)?
any double layer of peritoneum which connects a portion of intestine to the body wall
What is the definition of mesentery (specific)?
- the double layer of peritoneum which connects the jejunum and ileum to the body wall
- sometimes referred to as the “mesentery proper”
Describe the mesentery (of the jejunum and ileum).
suspends the jejunum and ileum from the posterior body wall and transmits the nerves and vessels which supply them
Describe the transverse mesocolon.
connects the transverse colon to the posterior body wall
Describe the sigmoid mesocolon.
- connects the sigmoid colon to the pelvic wall
Describe the mesoappendix.
connects the appendix to the mesentery of the ileum
Describe the phrenicocolic ligament.
- 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
What are the subdivisions of the peritoneal cavity?
- omental bursa (lesser sac)
- greater sac
Describe the omental bursa (lesser sac).
- 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
Describe the greater sac.
extends from the diaphragm to the pelvic floor and across the entire breadth of the abdominal cavity
What are the subdivisions of the greater sac?
- right subphrenic space (recess)
- left subphrenic space (recess)
- subhepatic space (recess)
+ hepatorenal recess - right paracolic gutter
- left paracolic gutter
Describe the right subphrenic space (recess).
located below the diaphragm and above the liver, to the right of the falciform ligament
Describe the left subphrenic space (recess).
located below the diaphragm and above the liver, to the left of the falciform ligament
Describe the subhepatic space (recess).
between the liver and the transverse colon
Describe the hepatorenal recess.
posterosuperior extension of the subhepatic space, between the liver and right kidney
Describe the right paracolic gutter.
a longitudinal depression lateral to the ascending colon
Describe the left paracolic gutter.
a longitudinal depression lateral to the descending colon
What is clinically important about the subdivisions of the greater sac?
they channel and compartmentalize peritoneal fluid and infectious processes
What is a perforated duodenal ulcer?
- fluid enters the subhepatic recess
- then to the right paracolic gutter
- accumulates in the right iliac fossa
- leads to peritonitis
- often leads to appendicitis
What is the omental foramen?
the opening between the omental bursa and greater sac
What are the boundaries of the omental foramen?
- liver (superiorly)
- first part of the duodenum (inferiorly)
- free edge of the lesser omentum (anteriorly)
- peritoneum covering the inferior vena cava (posteriorly)
Which structures pass through the porta hepatis and are surrounded by the lesser omentum?
- 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)
