Abdominal viscera Flashcards
(28 cards)
Name the 2 omentas and what do they derive from?
1) Greater omentum - from the dorsal mesentery
2) Lesser omentum - from the ventral mesentery
To what does the greater omentum attach?
The greater omentum attaches to the greater curvature of the stomach and the first part of the duodenum
Describe the route of the greater omentum
Inferior —- superior
Inferiorly ascends to cover the abdomen including the transverse colon and coils of the jejunum and ileum
Superiorly it becomes adherent to the peritoneum of the transverse colon superiorly and the anterior layer of the transverse mesocolon as it passes posteriorly and arrives at the posterior abdominal wall
It attaches to the greater curvatures of the stomach and the first part of the duodenum
To what does the lesser omentum attach?
The lesser omentum attaches to the lesser curvature of the stomach and the first part of the duodenum as it rises to the inferior border of the liver
Which 2 vessels are enclosed within the greater omentum peritoneal bi-layer just inferior to the greater curvature of the stomach?
The right and left gastro-omental vessels
What 2 regions can the lesser omentum be divided into?
1) The hepatogastric ligament - medially, extending from the lesser curvature of the stomach to the inferior border of the liver
2) The hepatoduodenal ligament - laterally, extending from the first part of the duodenum to the inferior border of the liver
What is the significance of the lateral margin of the hepatoduodenal ligament and what does it enclose?
The lateral margin of the hepatoduodenal ligament (the lateral region of the lesser omentum which extends from the first part of the duodenum to the inferior surface of the liver) is a free margin which serves as the anterior border of the epiploic (omental) foramen . The omental foramen is the gap between the lesser and greater omental sacs. Enclosed within the omental foramen is the hepatic artery proper, the portal vein and bile duct
What causes paralytic ileus and how does the omentum react?
When a region of the colon is inflamed and thus stops peristaltic movements - this is paralytic ileus. The rest of the colon contiunes peristalsis while this region is aperistaltic - this causes massaging of the overlying greater omentum towards the aperistaltic region, to which the greater omentum then becomes adherent. This omental covering tries to reduce spread of the inflammation within the abdominal cavity
1) What is the significance of the omentum with regards metastatic spread and in which cancer in particular
2) What is the name of the sign visible on CT due to metastatic spread throught the omentum?
1) Direct omental spread via a trans-coelomic route . Common in ovarian carcinoma
2) The omentum becomes significantly thickened - “omental cake”
Which 2 vessels are contained between the layers of the lesser omentum and whereabouts are they?
The right and left gastric vessels near the lesser curvature of the stomach
What is the generic structural role of the mesenteries - i.e. aside from providing a conduit for vessels and lymphatics?
To attach the viscera to the posterior abdominal wall
What are the 3 mesenteries?
1) The Mesentery - associated with parts of the small intestine
2) The Transverse Mesocolon
3) The Sigmoid Mesocolon
The mesenteries are derivatives of the…
The mesenteries are derivatives of the dorsal mesentery
The mesentery connects what structures to the posterior abdominal wall?
The mesentery connects the jejunum and ileum to the posterior abdominal wall
Describe the route of the mesentery
Superior attachment at the duodenojejunal junction just to the left of the upper lumbar part of the vertebral column
It passes obliquely downwards and to the right, ending at the ileo-caecal junction near the upper border of the right sacro-iliac joint
What passes within the mesenteries and what do they supply / drain?
The vessels, nerves and lymphatics that supply the jejunum / ileum
What structure does the transverse mesocolon connect to the posterior abdominal wall?
The transverse mesocolon connects the transverse colon to the posterior abdominal wall
What passes within the transverse mesocolon and what do they supply / drain?
The vessels, nerves and lympathics supplying the transverse colon
The …layer of the transverse mesocolon is adherent with the …. layer of the ……
The anterior layer of the transverse mesocolon is adherent with the posterior layer of the greater omentum
What structure does the sigmoid mesocolon connect to the posterior abdominal wall?
The sigmoid mesocolon connects the sigmoid colon to the posterior abdominal wall
Describe the shape of the sigmoid mesocolon and its route
The sigmoid mesocolon is an ‘inverted-V’ shape with its apex at the branching of the common iliac artery into the internal and external iliac arteries. The left limb of the ‘v’ passes near the medial border of the left psoas muscle and the right limb of the ‘v’ descends into the pelvis to end at the level of vertebra S3
What passes within the sigmoid mesocolon and what do they supply / drain?
The sigmoid and superior rectal vessels along with the nerves and lymphatics associated with the sigmoid colon
Name two peritoneal ligaments
1) Splenorenal ligament
2) Gastrophrenic ligament
Describe the site of emergence of the abdominal oesophagus and the vertebral level
The abdominal oesophagus emerges from the right crus of the diaphragm at the oesophageal hiatus at vertebral level TX and then connects to the stomach at the pyloric orifice just left of the midline
