1-5 Abdominal Organization and Peritoneum Flashcards
What are the lines that are used to divide the surface abdomen into 9 parts? What’s the orientation?
Vertical - 2 midclavicular lines
Horizontal -
subcostal line - inferior to 10th rib
transtubercular line - passes through tubercles of iliac crests
What is the orientation of the lines that divide the surface of the abdomen into quadrants?
2 perpendicular lines which intersect at the umbilicus
What are the limits of the abdominopelvic cavity?
Thoracoabdominal diaphragm (superior) (pelvic brim in between) Pelvic diaphragm (inferior)
What are the connective in the abdominopelvic cavity? (superficial to deep)
- Transversalis fascia
- Extraperitoneal connective tissue
- Peritoneum
What does transversalis fascia line?
Entire abdominopelvic cavity - doesn’t extend into mesenteries
What attaches viscera to posterior abdominal wall?
Mesenteries
What does extraperitoneal connective tissue line? What is the tissue made up of?
Underlies all visceral peritoneum - AKA subserous fascia
Loose areolar and fatty layer
- between transversalis fascia and parietal peritoneum
What does the peritoneum line? What does it support?
A mesothelial layer (simple squamous epithelium of mesodermal origin)
lines the abdominopelvic cavity (parietal)
covers the organs suspended within it and forms all mesenteries (visceral)
What is the serosa in the peritoneum? Where is it secreted, and what is it’s purpose?
Mesothelium along with an accompanying layer of submesothelial connective tissue form a serosa which secretes a thin, watery fluid (serous fluid) that reduces friction between opposing peritoneal surfaces
Is the peritoneum an open or closed sac?
Closed - the abdominal organs are pushed into it and suspended
What is the area within the peritoneal sac? What are the contents?
The area within the peritoneal sac is referred to as the peritoneal cavity and its only normal content is serous fluid.
In what cavity are abdominal organs housed?
abdominal cavity
How is the peritoneal cavity divided?
greater and lesser peritoneal sac
What does the greater sac of the peritoneum include?
The greater sac includes all areas within the peritoneal cavity except the area housed within the omental bursa
What are mesenteries? What is another name for them? What do they often contain?
Mesenteries are duplications of peritoneum which are reflected against one another (two layers) as parietal peritoneum transitions into visceral peritoneum
often referred to as peritoneal ligaments
possess a core of extraperitoneal CT in which vessels, nerves and lymphatics course to and from organs
What are peritonealized or intraperitoneal organs?
Organs covered and suspended by a mesentery
What are organs that are covered by peritoneum on one surface?
retroperitoneal, extraperitoneal or subperitoneal
How are retroperitoneal organs suspended?
Retroperitoneal structures are affixed directly to the posterior abdominal wall and are not suspended by a mesentery
What are primary retroperitoneal organs?
Primarily retroperitoneal are organs which originally developed in a retroperitoneal position, i.e. kidney
What are secondary retroperitoneal organs? What are some secondary retroperitoneal organs?
Secondarily retroperitoneal are organs which were originally peritonealized, but upon fixation to the posterior body wall during development, became retroperitoneal
Includes: duodenum, ascending and descending colon
How is the abdominopelvic cavity compartmentalized in a general sense? What divides it?
The abdominopelvic peritoneal cavity is divided transversely at the level of the transverse colon into supracolic and infracolic compartments by the passage of the transverse mesocolon
Where is the infracolic compartment?
Peritonealized area directly inferior to the transverse colon and its associated mesocolon
What does the infracolic compartment house?
small intestine
What divides the infracolic compartment?
Subdivided into right and left infracolic compartments by the passage of the mesentery proper
What are the boundaries of the right infracolic compartment?
Superior: Transverse colon and its mesocolon
Right: Ascending colon
Left: Right side of the root of the mesentery Inferiorly: Root of the mesentery and cecum
What are the boundaries of the left infracolic compartment?
Superior: Transverse colon and its mesocolon
Right: Left side of the root of the mesentery Left: Descending colon
Inferior: Sigmoid colon
What are the paracolic gutters? Where are they located?
Paired, right and left areas of the infracolic compartment which exist lateral to the ascending and descending colon
What does the right paracolic gutter communicate with?
communicates above with the hepatorenal recess and the pelvic peritoneal cavity below
What does the left paracolic gutter communicate with?
closed superiorly by the phrenicocolic ligament and opens inferiorly to the pelvic peritoneal cavity
Where is the supracolic compartment?
Peritonealized area between the thoracoabdominal diaphragm and the transverse colon and its associated mesocolon
What are the contents of the supracolic compartment?
Contains the stomach, spleen, liver, gall bladder, and part one of the duodenum
What further subdivides the supracolic compartment?
Further subdivided by the lesser omentum thereby forming the omental bursa
What is the dorsal mesentary, in a functional sense?
Attachments of the gut to the posterior body wall
What is the greater omentum? What is it an extension of?
Extension of dorsal mesentery from the greater curvature of the stomach and proximal duodenum
Where is the greater omentum located? What does it cover and what does it become?
Extends anteriorly over the small intestine, loops back to the transverse colon where it fuses with itself to form the gastrocolic ligament
What is the gastrocolic ligament made out of?
Greater omentum
What does the greater omentum house?
Houses the inferior recess of the lesser peritoneal sac
What 5 ligaments arise from the mesentery?
Gastrophrenic ligament Gastrosplenic ligament Phrenicosplenic ligament Splenorenal ligament Phrenicocolic ligament
What does the gastrophrenic ligament connect?
fundus of stomach to diaphragm
What does the gastrosplenic ligament connect?
greater curvature of stomach to spleen
What does the phrenicosplenic ligament connect?
diaphragm to superolateral portion of the spleen
What does the splenorenal ligament connect?
hilum of spleen to superior pole of left kidney
What does the phrenicocolic ligament connect? What does it do?
from diaphragm to the left colic flexure
Supports the spleen
Prevents ascites from entering the supracolic compartment via the left paracolic gutter
What does the mesentery proper attach to?
posterior abdominal wall to the jejunum and ileum along a line from the re-entry point of the duodenum into the peritoneal cavity to the cecum
Where is the supraduodenal fold? What does it house?
located above the duodenojejunal flexure
houses the supraduodenal fossae posterior to it that is entered from below
What is the infraduodenal fold? What does it house?
located below duodenojejunal flexure
houses the infraduodenal fossa which is entered from above
What is the retroduodenal fossa? Where is it?
peritoneal recess located dorsal to part 4 of the duodenum as it re-peritonealizes
Where is the paraduodenal fold? What is near it? What does it house?
located to the left of the duodenum
raised by the underlying inferior mesenteric vein
houses the paraduodenal fossa
What does the mesoappendix attach to?
posterior abdominal wall to vermiform appendix
What does the mesoappendix attach to?
posterior abdominal wall to vermiform appendix
What does the transverse mesocolon attach to?
posterior abdominal wall to transverse colon
What does the sigmoid mesocolon attach to?
posterior abdominopelvic area to sigmoid colon
What structures are part of the ventral mesentery?
Lesser omentum Omental bursa Falciform ligament Coronary ligaments Triangular ligaments
What structures are part of the ventral mesentery?
Lesser omentum
Omental bursa
Falciform ligament
Where is the lesser omentum?
extends from the lesser curvature of the stomach and duodenum to the hilum of the liver (porta hepatis)
How is the lesser omentum divided?
(1) Hepatogastric ligament
(2) Hepatoduodenal ligament
What travels near the hepatoduodenal ligament?
The proper hepatic artery, portal vein and common bile duct travel within the extreme right edge of the hepatoduodenal ligament
Where is the omental bursa located?
Located posterior to the lesser omentum
What is an important landmark associated with the omental bursa?
Epiploic foramen (Winslow) entrance to the omental bursa
What are the boundaries of the omental bursa?
Anterior: Hepatoduodenal ligament
Superior: Visceral surface of the liver
Posterior: IVC and right crus of the diaphragm
Inferior: Part one of the duodenum
What is the falciform ligament? What does it house - or what did it used to house?
Ventral attachment of the liver to the body wall
houses the ligamentum teres hepatitis (obliterated umbilical vein) within its inferior edge
What is the embryological importance of the peritoneum that surrounds the liver?
The liver develops within the ventral mesogastrium
The peritoneum that envelops the liver in the adult is of ventral origin
What are the coronary ligaments?
Peritoneum which attaches the superior surface of the liver to the abdominal surfaces of the diaphragm (divisible into anterior, posterior, left and right)
Encircles the superior portion of the liver like a crown, hence coronary. Think: coronation
What are the triangular ligaments?
where anterior and posterior coronary ligaments meet they form right and left triangular ligaments, respectively
Does the liver have an area that isn’t peritonealized?
Yes - the bare area of the liver
Left and right anterior and posterior coronary ligaments meet only laterally relative to the liver forming the triangular ligaments, the area between lies in direct contact with the visceral surface of the diaphragm
