Peritoneum Flashcards
Describe the mesothelium of the peritoneum
Layer of simple squamous epithelial-like cells with supportive layer of connective tissue
What are the two layers of the peritoneum?
Parietal: lines the abdominal wall/peritoneal cavity
Visceral: reflects onto and covers organs
Where is peritoneal fluid?
Between parietal and visceral layers of peritoneum
The peritoneal cavity develops from…
It is connected to… at umbilicus until week 10
develops from intraembryonic coelom (embryonic body cavity) and is connected to extraembryonic coelom until week 10
Parietal peritoneum/mesothelium is derived from…
somatic mesoderm
Visceral peritoneum/mesothelium is derived from…
splanchnic mesoderm
Intraperitoneal organs are…
nearly completely covered by visceral peritoneum
Where are extraperitoneal organs?
What are their coverings?
external to parietal peritoneum, partially covered with visceral peritoneum
Where are retroperitoneal organs?
Posterior to parietal peritoneum, against posterior abdominal wall
Describe the coverings of retroperitoneal organs
One or part of one organ surface, usually the anterior surface, covered by parietal peritoneum
Where are subperitoneal organs?
Inferior to parietal peritoneum
Describe the coverings of subperitoneal organs
Superior surface of organ is covered by parietal peritoneum
In the development of the peritoneal cavity, how do developing organs acquire visceral peritoneum covering?
They protrude into the peritoneal sac
How do primarily retroperitoneal organs develop in the peritoneal cavity?
They do not protrude fully and remain partially behind the parietal peritoneum
How do secondarily retroperitoneal organs develop in the peritoneal cavity?
Organs are lying against posterior abdominal wall so their dorsal mesentery fuses with the posterior abdominal wall
Mesenteries are… connecting… containing…
Double layers of peritoneum connecting organ to body wall (suspend viscera) containing vessels and nerves
What are reflections in the peritoneal cavity?
Bends in the parietal peritoneum following the conical structure of the abdomen
What are recesses in the peritoneal cavity?
Spaces created by the parietal peritoneal reflections
Name the peritoneal folds
- Median umbilical fold
- Medial umbilical folds
- Lateral Umbilical folds
Where is the median umbilical fold?
Apex of bladder to umbilicus covering the median umbilical ligament (remnant of embryonic urachus/allantois)
Where are medial umbilical folds?
Covering medial umbilical ligaments (occluded umbilical arteries)
What separates median and medial umbilical folds?
Supravesical fossae
Where are lateral umbilical folds?
Covering inferior epigastric vessels
Where are the supravesical fossae?
Median to medial umbilical folds
Where are the medial inguinal fossae?
Medial to lateral umbilical folds; the site of direct inguinal hernias
Where are the lateral inguinal fossae?
Lateral to the lateral umbilical folds and contain deep inguinal ring; common site of indirect inguinal hernias
What is the blood supply of the parietal peritoneum?
Blood supply from branches of body wall vessels
Where are somatic afferents of the parietal peritoneum from?
Associated spinal nerves
What does the parietal peritoneum sense? How is pain perceived?
Interior body wall pressure, pain, heat and cold, and laceration are sensed
Pain is well-localized
What does the visceral peritoneum sense? How is pain perceived?
Not sensitive to touch, heat and cold, or laceration, but stimulated by stretching and chemical irritation
Pain is non-specific; referred discomfort
What is the blood supply of visceral peritoneum?
Same as viscera
Visceral afferents accompany…
autonomic nerves (sympathetic and parasympathetic)
Ligaments can connect two bones, but some connect…
viscera to one another
Do mesenteries contain neurovasculature?
Yes
List the major mesenteries and their associated organs
- Small intestines have principle mesentery (“the mesentery”)
- Vermiform appendix has mesoappendix
- Transverse colon has transverse mesocolon
- Sigmoid colon has sigmoid mesocolon
Describe omenta
Passes between stomach and other organs and contain neurovasculature
How many layers of peritoneum are in the greater omentum?
4
Where is the greater omentum?
Greater curvature of stomach and proximal duodenum
The greater omentum folds back to attach to…
transverse colon and transverse mesocolon
What structures attach the greater omentum to the transverse colon and transverse mesocolon?
- Gastrophrenic ligament
- Gastrosplenic ligament
- Gastrocolic ligament
How many layers of peritoneum are in the lesser omentum?
2
Where is the lesser omentum?
Lesser curvature of stomach and proximal duodenum to liver
What structures attach the lesser omentum to the stomach and liver?
- Hepatogastric ligament
- Hepatoduodenal ligament
What can be found in the hepatoduodenal ligament (attaching the lesser omentum to the duodenum)?
Portal triad
The falciform ligament contains…
the round ligament of the liver
The round ligament of the liver is also know as…
ligamentum teres hepatis
The round ligament of the liver is a remnant of the…
umbilical vein
What is the greater sac of the peritoneal cavity?
Main portion of cavity
The greater sac of the peritoneal cavity is divided by the…
transverse colon
The supracolic space of the greater sac contains…
the stomach, liver, and spleen
Where is the infracolic space of the greater sac?
Inferior to transverse colon, posterior to greater omentum
The infracolic space of the greater sac contains…
small intestines, ascending and descending colon
The right and left infracolic space of the greater sac is divided by the…
principle mesentery
Where is the right paracolic gutter?
Lateral to ascending colon
Where is the left paracolic gutter?
Lateral to descending colon
Where is the lesser sac of the peritoneal cavity (omental bursa)?
Posterior to stomach and lesser omentum
What is the anterior border of the omental foramen?
Hepatoduodenal ligament
What is the posterior border of the omental foramen?
Retroperitoneal IVC, right crus of diaphragm
What is the superior border of the omental foramen?
Liver
What is the inferior border of the omental foramen?
Superior or first part of duodenum
What is another name for the omental foramen?
Epiploic foramen/foramen of Winslow
Which organs do not have a free mesentery in adults?
Retroperitoneal organs: kidneys/ureters, duodenum, ascending/descending colon, parts of pancreas, aorta, inferior vena cava, and iliopsoas muscle
The omental foramen is bound anteriorly by…
- Hepatic artery
- Bile duct
- Portal vein
- Hepatoduodenal ligament
Posterior to the omental foramen is the peritoneum covering…
inferior vena cava
