Anatomy 10 Flashcards
What is the parietal peritoneum?
Lines the abdominal wall.
- It can be seen with naked eye and is innervated by the somatic nerves that supply the overlying muscles and skin of the abdominal wall.
- Pain from the parietal peritoneum is usually sharp, severe, and well localised to the abdominal wall.
What is the visceral peritoneum?
Covers the abdominal viscera.
- It is adhered to the surface of the viscera and cannot be seen with the naked eye.
- The visceral peritoneum is innervated by visceral sensory nerves. These nerves convey ‘painful’ sensations back to the CNS along the path of the sympathetic nerves that innervate the organ/structure it covers.
- Pain from the visceral peritoneum can be severe. It is usually dull and diffuse (i.e. it cannot be pinpointed to a specific location).
- ‘Painful’ sensations from the visceral peritoneum may be perceived as nausea or distension.
Where does the peritoneal cavity lie?
Between the parietal and visceral peritoneum
In a healthy abdomen what lies in the peritoneal cavity and what does it do?
Peritoneal fluid
Allows the viscera to slide freely alongside each other
What is meant by intraperitoneal?
Almost completely covered by peritoneum e.g. the stomach
What is meant by retroperitoneal?
Posterior to the peritoneum, hence only covered by peritoneum on their anterior surface e.g. the pancreas and abdominal aorta.
What is meant by secondarily retroperitoneal?
These organs were intraperitoneal in early development but came to be ‘stuck down’ onto the posterior abdominal wall.
What do the Mesenteries, Omenta, Ligaments, Folds do?
- They are all composed of peritoneum and connect organs to each other and to the abdominal wall.
- They may carry blood vessels, nerves, and lymphatics to the viscera.
- They contain a variable amount of fat; some are usually very fatty (the omenta).
What are the mesenteries?
Folds of peritoneum that contain fat and suspend the small
intestine and parts of the large intestine from the posterior abdominal wall.
Arteries that supply the intestine (from the abdominal aorta) and veins that drain the gut (tributaries of the portal venous system) are embedded in the mesenteries.
What are the greater and lesser omenta?
Folds of peritoneum that are usually fatty and connect the stomach to other organs.
- The greater omentum hangs from the greater curvature of the stomach and lies superficial to the small intestine.
- The lesser omentum connects the stomach and duodenum (the first part of the small intestine) to the liver. The hepatic artery, the hepatic portal vein, and the bile duct (the ‘portal triad’) are embedded within its free edge.
What are ligaments?
Folds of peritoneum that connect organs to each other or to the
abdominal wall.
What is the falciform ligament?
Connects the anterior surface of the liver to the anterior abdominal wall
What are the coronary and triangular ligaments?
Connect the superior surface of the liver to the diaphragm.
What are the peritoneal folds?
Raised from the internal aspect of the lower abdominal wall and
are created by the structures they overlie.
Sometimes they are difficult to see
What are the median umbilical folds?
Lie in the midline and represents the remnant of the urachus, an embryological structure that connected the bladder to the
umbilicus.
What are the medial umbilical folds?
Found lateral to the median umbilical fold
These represent the remnants of the paired umbilical arteries, which returned venous blood to the placenta in foetal life.
What are the lateral umbilical folds?
Found lateral to the medial umbilical folds
The inferior epigastric arteries lie deep to these peritoneal folds. They supply the anterior abdominal wall.
What is the peritoneal cavity divided into?
The smaller lesser sac
The larger greater sac
What is the smaller lesser sac?
(also called the omental bursa) is a space that lies posterior to the stomach and anterior to the pancreas.
What is the larger greater sac?
Remaining part of the peritoneal cavity.
- The greater and lesser sacs communicate with each other via a passageway that lies posterior to the free edge of the lesser omentum, the epiploic foramen (also called the omental foramen).
What does the gastrointestinal system develop from?
Develops from the embryonic gut tube which lies in the midline of the abdominal cavity, suspended from the posterior abdominal wall by the dorsal mesentery.
What does the dorsal mesentery do?
Major branches of the abdominal aorta that supply the developing gut tube travel through the dorsal mesentery
What does the ventral mesentery do?
Connects the stomach to the anterior abdominal wall. As the liver grows within it, the anterior part of the ventral mesentery becomes the falciform ligament and the posterior part becomes the lesser omentum.
What did the growth, migration and rotation of organs during development cause?
Responsible for the formation of the lesser sac and results in some organs being ‘pushed’ onto the posterior abdominal wall and becoming retroperitoneal.
