Part 3: Peritoneum Flashcards
What is the structure of peritoneum?
single layer of flattened mesothelium cells with overlying areolar tissue
How many peritoneal folds are there in the anterior abdominal wall? What are they?
6, 1 above and 5 below umbilicus
1 above: Falciform ligament
below:
1x median umbilical fold - midline, remains of urachus
2x medial umbilical ligament: obliterated umbilical arteries
2x lateral umbilical fold: inferior epigastric vessels
What is the falciform ligament?
ligament from umbilicus to xiphisternum. Contains ligamentum teres (remains of L umbilical vein) and enters the fissure of the ligamentum teres on surface of liver
What is the greater sac?
Main abdominal cavity
What is the lesser sac?
Invagination of greater sac behind the stomach via the epiploic foramen
What function does the lesser sac provide?
Allows mobility for posterior surface of stomach by providing potential cavity
What are the boundaries of the lesser sac?
Roof - caudate lobe of liver
Anterior wall - lesser omentum and stomach
Left - spleen (lienorenal and gastrosplenic ligaments)
Posterior wall - peritoneum overlying pancreas, L kidney and lower part is made of transverse mesocolon
Where does the greater omentum arise?
From greater curvature of stomach, consists of two closely applied layers of peritoneum enclosing blood vessels and lymphatics. Has continuous attachment from oesophagus to duodenum across lower border of stomach
Was is the role of the greater omentum
Policeman of abdomen - walls off infection
Where does the lesser omentum arise?
Extends between liver and upper border (lesser curvature) of stomach. Attaches to fissure of ligamentum venosum
What is the epiploic foramen? What are it’s boundaries?
2.5cm vertical slit between greater and lesser sac
Upper boundary - caudate lobe of liver
Lower boundary - ascending 1st part duodenum
Anterior boundary - R free margin of lesser omentum
Posterior boundary - IVC covered by peritoneum
What is within the R free margin of lesser omentum?
portal vein at back
Hepatic artery in front
CBD to front and R of vein
The abdomen can be divided into supra and infracolic compartments - what is the division of these compartments?
Transverse mesocolon attachment to posterior wall (over R kidney, duodenum, lower border of pancreas, lower part L kidney
What are the divisions of the right and left upper supracolic compartments?
R subphrenic (subdiaphragmatic): Between liver and diaphragm. R falciform makes medial boundary, upper coronary forms posterior boundary Left subphrenic (subdiaphragmatic): falciform is R boundary, upper coronary makes posterior boundary
What are the divisions of the right and left lower supracolic compartments?
Right subhepatic (hepatorenal pouch of Morison): between liver and kidney, bound posteriorly by lower coronary ligament
Left subhepatic region:
Also known as lesser sac
The infracolic region is divided into how many compartments by what?
2 compartments - upper(right) and lower(left)
Formed by attachment of mesentary to posterior wall across oblique line from L to R
What is the course of the mesenteric root?
Upper left to lower right. Past DJ junction, aorta, IVC, R psoas, R ureter. About 15cm long.
What are the boundaries of the right(upper) infracolic compartment?
Apex: Ileocecal junction R: Ascending colon L: Attachment of mesentery Base: transverse mesocolon Floor: Lower pole R kidney, R colic vessels, 2 part duodenum, DJ flexure
What is the R paracolic gutter?
Lies lateral to ascending colon and can be traced from hepatorenal pouch to pelvis - easy pathways for fluid
What are the boundaries of left (lower) infracolic compartment?
Upper: Transverse mesocolon R: Mesentery attachment L: descending colon Lower: Attachment of sigmoid colon Floor: 4th part of duodenum, inferior pole L kidney, sigmoid colon, L ureter near apex
Describe the L para-colic gutter
Lateral to descending colon. Limited by the phrenicocolic ligament between diaphragm and colon at splenic flexure. This helps prevent upward spread of infection on L side
