What does the parietal peritoneum line?
What is the peritoneal cavity?
parietal peritoneum lines the abdominal cavity, visceral peritoneum invests most of the abdominal viscera
the peritoneal cavity is a potential space between the peritonea
During development, where do all organ primordia form and how do they protrude?
What are the kidneys designated? Why?
How do the stomach and spleen protrude?
during development, all organ primordia form along the posterior abdominal wall and protrude to varying degrees into the parietal peritoneum.
the kidneys protrude slightly and are designated retroperitoneal organs i.e., only their anterior surfaces are covered by visceral peritoneum.
the stomach and spleen protrude completely; thus they are completely invested by visceral peritoneum and designated intraperitoneal organs
What is the function of peritoneal fluid and lymph vessels in the peritoneal cavity?
What are mesenteries?
What do they provide?
mesenteries are continuities of the visceral and parietal peritonea that result from organ invaginations into the parietal peritoneum.
they provide access for branches from the retroperitoneal abdominal aorta and IVC to the intraperitoneal organs.
What forms the lesser omentum that extends to the liver?
Describe the course of the four-layered greater omentum
a double-layered extension of visceral peritonea from the stomach and proximal duodenum forms the lesser omentum that extends to the liver.
Where do somatic nerves that supply the abdominal wall also provide sensory innervation to?
What does distension or irritation of the parietal peritoneum activate?
somatic nerves that regionally supply the abdominal wall also provide sensory innervation to the regional parietal peritoneum.
distension or irritation of the parietal peritoneum activates the sensory fibers causing sharp, localized pain.
What are postsynaptic sympathetic fibers accompanied by? What does distension or irritation of these fibers do?
postsynaptic sympathetic fibers are accompanied by visceral sensory fibers; thus distension or irritation of the visceral peritoneum induces dull, diffuse sensations, which are referred to the epigastric, umbilical, and hypogastric (pubic) regions as visceral pain
What does a surgical incision through the anterolateral abdominal wall enter?
Where is the lesser sac?
What does the omanetal foramen connect?
a surgical incision through the anterolateral abdominal wall enters the greater sac, the largest part of the peritoneal cavity.
the lesser sac (aka omental bursa) lies posterior to the stomach and lesser omentum.
the omental foramen connects the greater and lesser sacs.
What does the transverse mesocolon divide?
What do the right and left paracolic gutters provide?
the transverse mesocolon (mesentery of the transverse colon) divides the abdominal cavity into supracolic and infracolic compartments.
the right and left paracolic gutters provide free communication between the compartments
How does the phrenic nerve provide an exception to the concept that pressure applied to the parietal peritoneum results in sharp, localized pain?
LOCALIZED PAIN OF PARIETAL PERITONEUM
• Parietal peritoneum served by same somatic nerve supply as the region of the wall it lines --> localized pain
o Senses pressure, pain, hot/cold, and laceration
• EXCEPTION: INF surface of the central part of the diaphragm --> innervated by phrenic nerves
Why can peritonitis be lethal and why is the linea alba a preferred site for ascites paracentesis?
• Can be lethal b/c of extent of peritoneal surfaces & rapid absorption of materials (like toxins)
• Linea alba preferred b/c SUP to empty bladder and avoids inferior epigastric artery
How can peritoneal adhesions cause emergency complications?
PERITONEAL ADHESIONS (abnormal attachments between visceral peritoneum of adj viscera or between visceral peritoneum of an organ and an adj abdominal wall)
• When damaged, peritoneum becomes inflamed --> becomes sticky due to fibrin
o After sticking to another structure, the healed peritoneum becomes fibrous --> this is an ADHESION
• Can cause intestinal obstruction when intestine becomes twisted around an adhesion (volvulus)
Why is the greater omentum a four-layered peritoneal fold?
GREATER OMENTUM – 2x2 layers of peritoneum (since the omentum courses down and folds back up)
How do functions of the greater omentum relate to its common displacement in the peritoneal cavity?
FUNCTIONS OF GREATER OMENTUM:
• Prevents visceral peritoneum from adhering to the parietal peritoneum
• Has considerable mobility and moves around the peritoneal cavity with peristaltic movements of the viscera
• Forms adhesions adjacent to an inflamed organ such as the appendix, sometimes walling it off and thereby protecting other viscera from it
o Common to find the omentum markedly displaced from the “normal” anatomical position
• Cushions the abdominal organs against injury
How do ascites and cancer cells spread within the peritoneal cavity?
FLOW OF ASCITIC FLUID & PUS
• Paracolic gutters provide pathways for the flow of ascitic fluid & cancer cells