Sem 1 - J - Peritoneum - Greater/lesser omentum & sac, omental (epiploic) foramen, mesentery proper, transverse mesocolon Flashcards
What is the serous membrane lining the abdominal cavity known as?
This is the peritoneum
The parietal peritoneum lines the walls of the abdominal cavity and the visceral peritoneum lines the organs in the abdominal cavity What lies between the parietal and visceral peritoneum? What is a double layer of peritoneum known as and what does it do?
Between the parietal and visceral peritoneum is the peritoneal space/cavity A double layer of peritoneum is known as a mesentery Mesenteries enclose the organ and connect it to the body wall
Sensitive to pain, touch, temperature and pressure - which peritoneum is this? Sensitive to stretch via ANS afferent fibres, over distension will lead to pain - which peritoneum is this?
The parietal peritoneum is sensitive to pain, touch, temperature and pressure via somatic sensory afferents as it lines the body wall The visceral peritoneum is sensitive to stretch via ANS afferent fibres and when the visceral peritoneum is over distended this will lead to pain As the viscera covers the surface of the organ, if the organ stretches the viscera will feel the stretch and this pain fibre will travel back along the dorsal roots of the spinal cord
What is the nerve supply to the parietal peritoneum?
The lining of the lateral and anterior walls of the parietal peritoneum is supplied by the lower 6 thoracic nerves The central part of the parietal peritoneum, the dipahragmatic parietal peritoneum, is supplied by the phrenic nerve The pelvic portion of the parietal peritoneum is supplied by the obturator nerve
What structures does the phrenic nerve supply?
The phrenic nerve supplies motor fibres to the diaphragm The phrenic nerve supplies sensory fibres to the diaphragmatic peritoneum, mediastinal pleura and fibrous peridcardium
There are different terms for organs associated with the peritoneum: Intraperitoneal Retroperitoneal Infraperitoneal What does it mean to have an intraperionteal organ? Name these organs Which parts of the small intestine, which parts of the colon
This means the organ is surrounded by mesentery except at its attachment point to the body wall Stomach, gallbladder, spleen, liver Small intestine (although only 1st part of duodenum) Caecum (some of appendix), transverse and sigmoid colon
What is the definition of a retroperitoneal organs? What is another word for retroperitoneal? Name the retroperitoneal organs
A retroperitoneal organ has never had a mesentery or the mesentery was lost in development Retroperitoneal organs are also known as extraperitoneal The organs are only partially covered in peritoneum Organs - Kidneys and suprarenal glands 2,3,4th parts of the duodenum and pancreas Ascending and descending colon Upper 2/3rds of the rectum
What is an infraperiotneal organ also known as? Name some organs
INfraperitoneal organs are also known as subperitoneal This includes the lower 1/3rd of the rectum and many pelvic organs
Okay -state the definition of an intraperitoneal, retroperitoneal and an infraperitoneal organ
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Name the intraperitoneal, retroperitoneal and infraperitoneal organs?
- INtraperitoneal organs -
- * stomach, gallbladder, spleen liver
- * Small intestine (only 1st part of the duodenum)
- * Caecum(some appendix), transverse& sigmoid colon
- Retroperitoneal (extraperitoneal) -
- kidneys and suprarenal glands
- * 2nd,3rd,4th part of the duodenum and pancreas
- * ascending and descending colon, 2/3rds of rectum
- Infraperitoneal (subperitoneal) -
- * lower 1/3rd rectum and many pelvic organs
What is the proportion of the abdominal cavity where all the intestines sit known as? It is inferior to the stomach What is the lining of this space known as?
The greater sac is the majority of the abdominal cavity and has the space for the intestines, it is inferior to the stomach and is lined by the greater omentum
The greater omentum can have a different appearance in different individuals, what are the two most common appearances? What is it also described as? _________ of the abdomen
The greater omentum can have a very thin and membranous appearance in some individuals and a fatty appearance in others It is described as the policeman of the abdomen
Where is the greater omentum suspended from proximally and what does it cover?
The greater omentum is suspended proximally from the greater curvature of the stomach and hangs over the anterior surface of transverse colon and covers the intestines
The stomach is an intraperitoneal organ with a double layer of peritoneum on either side (parietal and visceral), what does this anterior and posterior double layer of peritoneum meet up to form?
The two double layers form to form a quadruple layer known as the greater omentum
What does the transverse colon divide the pelvic cavity into?
This divides the pelvic into things above the transverse colon - supracolic - these are in the lesser sac (lesser sac is blue in diagram) and Things that are below the transverse colon - infracolic - these are in the greater sac (greater sac is in pink)
What is the transverse colons own small mesentery that attaches it to the body wall?
This would be the transverse mesocolon
How do both the right and left gastro-omental arteries arise from the descending aorta?
The right gastro-omental artery is a branch of the gastroduodenal artery which is a branch of the common hepatic artery - one of the trifurcations of the coeliac trunk from the aorta (T12) The left gastro-omental artery is a branch of the splenic artery which is a branch of the coeliac trunk
As said the blood supply to the greater omentum and greater curvature of the stomach (right and left gastro-omental (epiploic) arteries) are carried within the greater omentum What is the blood supply to the lesser curvature of the stomach?
The right gastric and left gastric arteries supply the lesser curvature of the stomach Right gastric - branch of the common hepatic artery branch of the coeliac trunk Left gastric - branch of the coeliac trunk
What is the lesser sac also known as? Where does it lie?
The lesser sac is also known as the omental bursa It is the portion of the peritoneal cavity posterior to the stomach and lesser omentum
Coming off the greater curvature you have the greater omentum closing off the lesser sac Coming off the lesser curvature you have the lesser omentum closing off the other portion off the lesser sac What is the area of communication between the greater and lesser sacs known as?
The area of communication is known as the omental (epiploic) foramen and it is found posterior to the free edge of the lesser omentum
What is the free edge of the lesser omentum also known as? What is found here? (in what orientation as well)
The free edge of the lesser omentum is also known as the hepatoduodenal ligament Found here is the hepatic artery (left), bile duct (right) and hepatic portal vein posteriorly
Mesentery ‘proper’ * Carries the vessels, nerves and lymphatics to/from most of the small intestine (jejunum and ileum) * Branches of the superior mesenteric artery / vein Transverse colon is the junction between midgut and hindgut, what arteries supply both of these? What is the ansastamoses of arteries just inferior to the transverse colon known as?
Midgut - superior mesenteric artery
Hindgut - inferior mesenteric artery
Anastamoses of the two arteries - marginal artery of Drummond (marginal artery of the colon)
