Disposition of Peritoneum Flashcards
What is the peritoneum?
Continuous transparent serous membrane that lines the abdominopelvic cavity and invests the viscera.
What is the parietal peritoneum?
Lines the internal surface of the abdominopelvic wall.
What is the visceral peritoneum?
Covers viscera such as the stomach and the intestines
What is the Mesentery?
Double layer of peritoneum that occurs as a result of the invagination of the peritoneum by an organ and constitutes a continuity of the visceral and parietal peritoneum - connects an intraperitoneal organ to body wall - usually the posterior abdominal wall
What is the Omentum?
Double-layered extension or fold of peritoneum that passes from stomach and proximal part of the duodenum to adjacent organs in the abdominal cavity.
What is the peritoneal ligament?
Consists of a double layer of peritoneum that connects an organ with another organ or to the abdominal wall
What developmental processes are involved in separating the greater from the lesser peritoneal sac?
The lesser sac is embryologically formed from an infolding of the greater omentum.
What peritoneal structures are derived from the ventral mesentery?
Liver
What peritoneal structures are derived from the dorsal mesentery?
Greater omentum of the stomach, jejunum and ileum as mesentery, transverse colon as the transverse mesocolon, sigmoid colon as sigmoid mesocolon.
What are the boundaries of the greater sac?
Greater sac: abdominal cavity outside of the lesser sac
Superior: diaphragm
Inferior: pelvic floor
Anterior: falciform ligament and umbilical folds
What are the boundaries of the lesser sac?
Anterior: quadrate lobe of the liver, stomach, lesser omentum, gastrocolic ligament
Posterior: pancreas
Left Lateral: Left kidney and adrenal gland
Right Lateral: Omental foramen and lesser omentum
How are the greater and lesser sacs connected?
Via the omental foramen (foramen of winslow or epiploic foramen) and is bounded by the portal vein, hepatic artery and the common bile duct.
How is the parietal peritoneum innervated?
Served by same blood and lymphatic vasculature and same somatic nerve supply as the region of the wall it lines.
How is the visceral peritoneum innervated?
Visceral peritoneum and organs it covers are served by same blood/lymphatic vasculature and visceral nerve supply.
What abdominal organs are present in the RUQ?
Liver (right lobe), Gallbladder, Stomach (pylorus), Duodenum (parts 1-3), Pancreas (head), Right suprarenal gland, Right kidney, Right colic (hepatic) flexure, Ascending colon (superior part), Transverse colon (right half)
What abdominal organs are present in the LUQ?
Left liver lobe, Spleen, Stomach, Jejunum and proximal ileum, left kidney, left suprarenal gland, left colic (splenic flexure), transverse colon (left half), descending colon (superior part)
What abdominal organs are present in the RLQ?
Cecum, appendix, most of ileum, ascending colon (inferior part), right ovary, right uterine tube, right ureter (abdominal part), right spermatic cord (abdominal part), uterus (if enlarged), urinary bladder (if very full).
What abdominal organs are present in the LLQ?
Sigmoid colon, descending colon (inferior part), left ovary, left uterine tube, left ureter (abdominal part), left spermatic cord (abdominal part), uterus (if enlarged), urinary bladder (if very full)
What organs are supplied by the Celiac trunk?
FOREGUT: esophagus, stomach, liver, gallbladder, pancreas, spleen
What organs are supplied by the Superior Mesenteric Artery?
MIDGUT: Jejunum, ileum, transverse colon, ascending colon, appendix, cecum.
What organs are supplied by the Inferior Mesenteric artery?
HINDGUT: Descending colon, sigmoid colon, proximal rectum
What organs are supplied by the Internal Pudendal artery?
Distal part of rectum and anal canal.
What vessels are involved in the anastomoses between branches of the aorta?
- Right and left gastric arteries anastomose to supply stomach
- Right and left gastroomental (gastroepiploic) arteries anastomose to supply stomach
- Superior and inferior pancreaticoduodenal arteries anastomose to supply the duodenum
- Ileocolic and right arteries and right branch of middle colic artery and left colic and sigmoid arteries all anastomose with the marginal artery which supplies the colon
What is the purpose of anastomoses?
Provide collateral circulation in cases of obstruction of one vessel.
What is a Portal System?
Any system of blood vessels that has a capillary network at each end.
What is the Hepatic Portal System?
Receives blood from the GI tract and directs it to the liver. Substances absorbed by the small intestines travel first to the liver for processing before returning to the heart and general circulation. This is called First Pass Metabolism.
What does the Portal Vein contain?
Low oxygen, high nutrient blood from the GI tract and spleen.
What are the major vessels that form the hepatic portal system?
Hepatic portal vein is formed from the union of the superior mesenteric and splenic veins.
What are the major vessels that form the hepatic portal system?
Hepatic portal vein is formed from the union of the superior mesenteric and splenic veins.
What additional vessel contributes to the hepatic portal system in one third of people?
Inferior mesenteric vein also joins superior mesenteric and splenic veins.
What three locations are sites of potential portal-caval anastomoses?
- Esophagus
- Umbilicus
- Rectum
What vessels are involved in the esophageal portal-caval anastomoses?
Left gastric and azygous veins.
What is the clinical significance of the esophageal portal-caval anastomoses?
Esophageal varices
What vessels are involved in the umbilicus portal-caval anastomoses?
Paraumbilical and small epigastric veins of anterior abdominal wall
What is the clinical significance of the umbilicus portal-caval anastomoses?
Caput medusae
What vessels are involved in the rectum portal-caval anastomoses?
Superior rectal and middle and inferior rectal veins
What is the clinical significance of the rectum portal-caval anastomoses?
Anorectal varices
What is Portal Hypertension?
Increased pressure in portal venous system
What are clinical observations seen in Portal Hypertension?
-Splenomegaly, ascites, abdominal pain
How do esophageal varices and varicose veins form from Portal Hypertension?
Large volumes of blood flowing from portal system to systemic system at anastomoses. It can result in varicose veins. If these get really dilated they can rupture and hemorrhage –> hematemesis (if esophageal varices)
