lecture 5 Flashcards
Abdominal cavity is lined with peritoneum
Parietal and visceral peritoneum
Abdominal cavity is lined with peritoneum - Parietal and visceral
- connects the viscera to the posterior abdominal wall
- As a result, many compartments and recesses are formed
- Parietal peritoneum
lines the abdominal wall
Visceral peritoneum
lines the viscera such as stomach and intestines
invaginates to cover majority of abdominal viscera.
Peritoneal adhesions
Fibrous bands that form abnormal connections:
- Visceral peritoneum = attaches to adjacent organ
- Visceral peritoneum attaches to parietal peritoneum
Intraperitoneal:
Intraperitoneal organs are surrounded by visceral peritoneum – covered anteriorly and posteriorly
EG: Stomach, liver and spleen
Retroperitoneal organs:
Only covered with parietal peritoneum – only covered anteriorly
- Can be further subdivided based on their embryological development
1. Primarily retrop. Organs developed and stayed outside of the parietal peritoneum
EG: esophagus, rectum and kidneys\
2. Secondary retrop. Organs were originally intraperitoneal and were suspended by mesentery
- Through embryogenesis they become retroperitoneal as their mesentery gets fused with post abdominal wall
EG: ascending and descending colon
Retroperitoneal structures are SAD PUCKER:
S = suprarenal (adrenal) glands
A = Aorta/IVC
D = Duodenum (except proximal 2cm – the duodenal cap)
P = Pancreas (except tail)
U = Ureters
C = Colon (ascending and descending parts)
K = Kidneys
E = esophagus
R =rectum
Mesentery:
- Double layer of peritoneum
- Attaches an organ to the posterior abdominal wall
- Provides pathway for blood vessels and nerves to the organ from body wall
Omentum:
= Double layer of peritoneum
* Attaches the stomach to another organ:
– Liver = lesser omentum
– Transverse colon = greater omentum
greater omentum
Part of the omentum which attaches stomach to the transverse colon
lesser omentum
Part of omentum that attaches the lesser curve of the stomach and duodenum to the liver
Lesser omentum ligaments
- On its free edge it is thickened – contains hepatoduodenal ligament
- Deeper into this area, find the membranous part of the lesser omentum – contains hepatogastrial ligament
- Hepatoduodenal ligament is NB as it allows passage to the portal triad in the area
Lesser omentum: Contains the Portal triad
- Lies within free edge of lesser omentum
- Contents lesser omentum:
– Common bile duct – Proper hepatic artery – Hepatic portal vein
= portal triad
Subdivisions of the peritoneal cavity
- Greater sac
– makes up majority of peritoneal cavity - Is sub-divided into Supracolic & infracolic compartments – by mesentery of transverse colon (aka transverse mesocolon)
Infracolic further divided into left and right colic spaces - Lesser sac (aka omental bursa)
- Peritoneal gutters
- Peritoneal recesses
These are pathways and accumulation areas for fluids that spread infections and inflammation
Lesser sac or Omental bursa
- Omental bursa (lesser sac)is small
- Located posterior to the stomach and lesser omentum.
- Superior recess extends behind liver
- Inferior recess between the layers of the greater omentum.
- Permits free movement of stomach as it ensures the stomach lies over the other structures
- Omental bursa communicates with greater sac via the omental foramen (epiploic foramen)
- Fluid in omental bursa can indicate perforation of the stomach or a collection of pancreatic fluid
Peritoneal recesses…1
As peritoneum wraps around the viscera, they form several fossa and spaces = recesses
Potential sites for herniation of pelvic viscera
Recesses serve to provide more room for viscera and therefore reduces congestion of structures within abdominal cavity
- Pouches of peritoneum formed by peritoneal folds
* – Duodenal recess
* – Caecal recesses:
* Superior ileocaecal
* Inferior ileocaecal
* Retrocaecal
* – Intersigmoid recess
Peritoneal recesses…2
- Right and left subphrenic recesses
Located below the diaphragm and above the liver - Hepatorenal recess:
Located between the liver and the right kidney
Drainage of fluid
In supracolic compartment:
Fluid to the right of the falciform lig. Above the liver and fluid from the inferior part of the liver will drain into the R paracolic gutter
Falciform lig blocks fluid from the left and forces it to go inf into the paracolic gutter
* Right paracolic gutter: either superior or inferior depending on position
Drainage of fluid:
In infracolic compartment:
- Accumulation on the right, between mesentry of jejenum and ileum and ascending colon (no exit)
- To the left of the root of the mesentery, between mesentery of jejenum and ileum and descending colon (exit inferior)
- Left paracolic gutter: towards inferior since phrenocolic ligament block superior drainage in supine position
