Abdomen 1 Flashcards
What is the peritoneum?
continuous membrane which lines the abdominal cavity and covers the abdominal organs (abdominal viscera)
What is the role of the peritoneum?
- Support the viscera
2. Providespathwaysfor blood vessels and lymph to travel to and from the viscera
What are the two layers of the peritoneum that are continuous with each other?
- parietal
2. visceral
What are both the parietal and visceral layers made of?
mesothelium (simple squamous epithelial cells)
What does the parietal perineum line?
internal surface of the abdominopelvic wall
What is the parietal perineum derived from?
somatic mesodermin the embryo
Why is pain from the parietal peritoneum well localised?
receives the samesomaticnerve supply as the region of the abdominal wall that it lines
What is the parietal peritoneum sensitive to?
- pressure
- pain
- laceration
- temperature
Where is the visceral peritoneum derived from?
splanchnic mesodermin the embryo
Why is pain from the visceral peritoneum poorly localised?
has the sameautonomicnerve supply as the viscera it covers
What is the visceral peritoneum sensitive to?
- stretch
- chemical irritation
How is pain from the visceral peritoneum referred to?
dermatomes
What are dermatomes supplied by?
same sensory ganglia and spinal cord segments as the nerve fibres innervating the viscera
What is the peritoneal cavity?
potential spacebetween the parietal and visceral peritoneum
What does the peritoneal cavity contain?
a small amount of lubricating fluid
When can you get damage to the peritoneum?
infection, surgery or injury
What could the formation of fibrous scar tissue result in?
abnormal attachmentsbetween the visceral peritoneum of adjacent organs or between visceral and parietal peritoneum
What would adhesions result in?
pain and complications such asvolvulus, when the intestine becomes twisted around an adhesion resulting in a bowel obstruction
What are intraperitoneal organs?
- enveloped by visceral peritoneum
- covers the organ both anteriorly and posteriorly
What are examples of intraperitoneal organs?
- stomach
- liver
- spleen
What are retroperitoneal organs covered in?
- not associated with visceral peritoneum
- only covered in parietal peritoneum
- that peritoneum only covers theiranterior surface
What are primary retroperitenial organs?
developed and remain outside of the parietal peritoneum
What are examples of retroperitenial organs?
- esophagus
- rectum
- kidneys
What were secondary retroperitoneal organs initially?
initially intraperitoneal suspended by mesentery
What happens to the secondary retroperitoneal organs through the course of embryogenesis?
- retroperitoneal as their mesentery fused with the posterior abdominal wall
- So in adults only anterior surface covered with peritoneum
What are examples of secondary retroperitoneal organs?
ascending and descendingcolon
What is the mesentery?
double layer of visceral peritoneum
What does the mesentery connect?
intraperitoneal organ to (usually) the posterior abdominal wall
What does the mesentery provide?
pathway for nerves, blood vessels and lymphatics to travel from the body wall to the viscera
What are omenta?
sheets of visceral peritoneum that extend from thestomach and proximal part of the duodenumto other abdominal organs
What does the greater omentum consist of?
four layers of visceral peritoneum
What is the journey of the greater omentum?
- descends from thegreater curvatureof the stomach and proximal part of the duodenum
- then folds back up and attaches to the anterior surface of the transverse colon.
What is the role of the greater omentum?
- immunity
- can migrate to infected viscera or to the site of surgical disturbance
What is the lesser omentum?
double layer of visceral peritoneum
What does the lesser omentum attach?
from thelesser curvatureof the stomach and the proximal part of the duodenum to the liver
What does the lesser omentum consist of?
- hepatogastric ligament (the flat, broad sheet)
2. hepatoduodenal ligament (the free edge, containing the portal triad).
What is the peritoneal ligament?
double fold of peritoneum that connects viscera together or connects viscera to the abdominal wall
What is an example of peritoneal ligament?
hepatogastric ligament - a portion of the lesser omentum, which connects the liver to the stomach
