Gut Rotation Flashcards
(21 cards)
Dorsal mesentery of stomach forms?
Greater omentum
Spleen
Ventral mesentery of stomach forms?
(Forms two parts w/ Liver in between)
Lesser omentum
Falciform ligament
Lesser omentum contains what three important vessels?
Proper hepatic A
Hepatic portal v
Common bile duct
Rest of the gut tube below the stomach contains only what type of mesentery?
Dorsal mesentary
Called “meso___”
ex: mesoduodenum
Organization of early gut tube
Everything in midline
Peritoneal cavity single below stomach
Divided into right and left halves at stomach
Right half of early gut tube at stomach level info
Gets much smaller-lesser peritoneal sac
Accessible in adults only via epiploic foramen of winslow
Left half of early gut tube at stomach level info
Remains continuous w/ rest of peritoneal cavity
Called peritoneal sac
First gut rotation
90 degrees around vertical axis
Mesenteries from dorsal go left, ventral go right
Liver ends up on right side
Second gut rotation
90 degrees along horizontal axis
Stomach now in adult location
Greater omentum @ greater curvature of stomach grows to cover intestines
Lesser omentum @ lesser curvature of stomach is very thin except hepatoduodenal part
What does the midgut loop form?
Small intestine
Ascending and Transverse colon
What vessel runs down center of loop?
Superior mesenteric artery (SMA)
What connects yolk sac to apex of midgut loop?
Vitelline duct
(Forms Meckel’s diverticulum within last 3’ of ileum)
Mid gut loop rotation
270 degrees CW
What happens to duodenum during midgut loop rotation?
Lies dorsal to SMA
All but first part are secondarily retroperitoneal
What does it mean to be secondarily retroperitoneal?
Mesentery is “lost” and fuses to post. wall of abdomin
What happens to colon during midgut loop rotation?
loops around SI from right to left
What all becomes secondarily retroperitoneal?
All but first part of duodenum
Ascending and Descending colon
What happens to transverse colon during midgut loop rotation?
Hangs onto its mesentery-transverse mesocolon
Trans. mesocolon covered by greater omentum and fuses to its deep surface
Where does spleen form?
Dorsal mesentery of stomach
Parts of dorsal mesentery are thickened ligaments that attach to spleen
(lienophrenic)
How does celiac trunk form?
Travel through dorsal mesentery on either side of stomach
Splenic branch-spleen, stomach
Common hepatic branch-liver, stomach, duodenum, pancreas
Left gastric branch-lesser curvature of stomach
How does pancreas form?
As two outgrowths of duodenum
Coalesce (but remain separate ducts) in dorsal mesentary
This mesentery fuses with parietal peritoneum so appears retroperitoneal
