Peritoneum Flashcards
Subdivisions of the alimentary canal
Nasal cavity Oral cavity Forgot Midgut Hindgut Anal canal
Where is the oral and anal cavity derived from
Stomodeum
Proctodeum
Both have membranes that must be broken to be accessed
What mesenteries support what sections of the GI tract
Dorsal mesentery supports fore, mid and hindgut
Ventral mesentery supports foregut
What blood vessels supply what sections of the GI tract
Abdominal aorta supplies foregut w coeliac trunk
Midgut w superior mesenteric
Hindgut w inferior mesenteric
Mesenteries
Ventral and dorsal
Allows vessels, nerves, lymphatics to flow and supply organs
Peritoneum types and areas
Parietal , lines insides of abdominal cavity
Intraperitoneal, surrounds mobile organs completely
Retroperitoneal, partially surrounds/doesnt surround organs, not mobile
Visceral, wraps around organs
Double membrane of peritoneum forms mesentery
Peritoneum in development
Intraperitoneal organs can be pushed to posterior abdominal wall, reabsorbs peritoneum => retroperitoneal
Occurs as result of elongation, rotation of gut during development
Plane structure of mesogastria from ventral to dorsal
Ventral mesogastrium Falciform ligament Liver Gastrohepatic/lesser omentum ligament Stomach Dorsal mesogastrium Gastriosplenic ligament Spleen Splenorenal/lienorenal ligament
Kidneys
Spaces either side of mesenteries, coelomic cavity
Location of organs in mesenteries
Liver, ventral mesentery
Spleen, pancreas, dorsal mesentery
Kidney, always retroperitoneal
How does the mesogastria develop
Liver grows on R more than L, swings to RHS
Swings dorsal mesentery to the L, brings spleen with it
Eventually traps some peritoneum behind it, forms lesser sac
Falciform ligament separates R and L greater sac
Gastrohepatic ligament, access from greater sac into lesser sac
Growth and rotation of stomach
Starts with ventral and dorsal mesentery, R and L vagus around gut tube Gut tube rotates clockwise L vagus => anterior vagus R vagus => posterior vagus Form anterior posterior vagal trunk
Dorsal mesentery => greater curvature
Ventral mesentery => lesser curvature
Greater curvature and mesentery grows => fat filled apron of tissue sits in front of intestines to form greater omentum
Function of the greater omentum
Formed from dorsal mesentery
Abdominal policeman, protects intestines from infection
When infection detected
Membrane becomes sticky, traps infection onto peritoneal membrane
V vascular structure, brings lymphocytes to destroy offending bacteria
Prevents infection from spreading
Development of the greater omentum
Starts as peritoneal fold, wraps around stomach, connects back to posterior abdominal wall
Also a double fold of peritoneum around transverse colon (transverse mesocolon)
Mesenteries fuse together = greater omentum, 4 membraned structure
Anchored onto transverse colon
Vessels in and location of free edge
Between greater and lesser sac
Common bile duct
Hepatic vein
Hepatic artery
Rotations of the guts and mesenteries
Dorsal mesentery connects mid and hind guts to posterior abdominal wall
As gut rotates, cannot retain all mesenteries, some reabsorbed, become retroperitoneal
