Development of the gut - general concepts (Dave's notes) Flashcards
(17 cards)
Which three arteries leave the aorta passing ventrally to the gut?
The dorsal mesogastrium
The dorsal mesentery
The dorsal mesocolon
Additionally there is a ventral mesogastrium carrying the left umbilical vein
What are the derivatives of the foregut and spleen supplied by?
The coeliac trunk
The liver is an outgrowth of what?
the liver is an outgrowth at the foregut/midgut junction and buds ventrally as two outgrowths
How does the pancreas develop?
As two outgrowths; one ventrally and one dorsally
Where does the spleen develop?
In the left leaf of the dorsal mesogastrium (but is not a direct derivative of??)
What four stages does lymph flow through?
Lymphoid follicles, gut margin nodes, mesenteric nodes, artery root nodes
When and from what does herniation occur?
From weeks six to ten the midgut herniates on the axis of the SMA
Into what does herniation occur? Where is the apex?
Herniation into the umbilical cord. The apex is at the site of the vitelointestinal duct
Describe the rotation of the gut
The distal limb goes up on the left, and the proximal limb goes down on the right (anticlockwise to the observer)
What happens to the duodenum?
The duodenum becomes plastered down with the mesentery of the transverse colon lying across it
Which part is the last to be re-included?
The caecum, which is initially high on the midline but tracks to the RIF
What happens to the dorsal mesentery?
It hinges to the right with posterior layers absorbed
What happens to the hind gut mesocolon?
It hinges to the left with posterior layers absorbed
Why is the liver notched by the falciform ligament?
Because it outstrips the ventral mesogastrium by growing caudally
What does the encroachment of the liver do to the ventral mesogastrium?
It divides the ventral mesogastrium into the falciform ligament and the lesser omentum which passes back to the left of the IVC to the diaphragm
What does cranial growth of the liver result in?
The bare areas by peeling apart the right and left layers
True/false:
From the midline, the
liver swings to the right
stomach swings to the left
the ventral bile duct swings to the right
The dorsal convexity of the stomach rotates to the right
The left side of the stomach now faces posteriorly
The dorsal mesogastrium swings across like a bifold door
The more caudal part of the dorsal mesogastrium gets rotated to form what???
True: the liver swings to the right
True: stomach swings to the left
False: the ventral bile duct swings medially
False: The dorsal convexity of the stomach rotates to the left (greater curvature)
False: The left side of the stomach now faces anteriorly
True: The dorsal mesogastrium swings across like a bifold door
False: The more caudal part of the dorsal mesogastrium gets absorbed from behind to form the greater omentum
