Embryology Flashcards
What 2 things does embryonic folding incorporate into the embryo?
Gut tube
coelom
What’s the deal with the mesenteries?
They surround the primitive gut tube as coelomic sacs…initially there is a dorsal & ventral mesentery–>then just a dorsal eventually
The primitive gut tube is connected to what?
the yolk sac
the connecting stalk is significant
When the folding is occurring to get the gut tube…what gets pinched off? WHat connects these 2 structures at first?
Yolk sac gets pinched off
vitelline duct
Where do the mucosa & glands of the GI come from?
the endoderm inside the gut tube!
Where do the smooth muscle & CT that surround this come from?
splanchnic mesoderm of the lateral plate
What composes a mesentery?
2 layers of peritoneum w/ underlying nerves & blood vessels
What are the 3 main regions of the embryo? And their blood supply?
Foregut: Celiac Trunk
Midgut: SMA
Hindgut: IMA
Describe the growth of the foregut.
It grows out & to the side. Think about the curve of the stomach.
In the foregut what is something special that isn’t present in other places?
Ventral mesentery–>provides support for things like the liver bud & gallbladder
When you have a ventral mesentery, like in the foregut–>is the dorsal mesentery continuous or discontinuous?
It is discontinuous. b/c the 2 sacs are still separated.
What are the 2 portions of the ventral mesentery that remain in the adult?
lesser omentum
falciform ligament
The dorsal mesentery grows quickly & folds on itself becoming the ______.
greater omentum
In the foregut the only way to get to the right coelomic sac is thru the _______.
epipleural foramen
Describe what the falciform ligament does.
It is a piece of mesentery. The placental blood travels along the anterior body wall & along the ligament & goes into the liver.
Is there a ventral mesentery in the midgut or hind gut?
NO. only in the foregut
Where does the region of the foregut end?
after the 2nd part of the duodenum
What does it mean to be primarily retroperitoneal?
It means that you never had a peritoneum.
What does it mean to be secondarily retroperitoneal?
It means that you initially had a peritoneum, but you lost it.
What does it mean to be peritonealized?
to be intraperitoneal