7: Embryology Flashcards
What is the communication from the midgut to the yolk sac during development?
Vitelline duct
Which germ layer does the epithelium, ducts and glands come from?
Endoderm
All GI stuff comes from the endoderm
Which germ layer does the lamina propria, smooth muscle and connective tissue come from?
VISCERAL mesoderm
During development, mesenteries form on the ventral and dorsal aspects of the gut. As organs become retroperitoneal, most of these mesenteries are lost.
What is an example of a ventral mesentery?
Falciform ligament
Lesser omentum
During development, mesenteries form on the ventral and dorsal aspects of the gut. As organs become retroperitoneal, most of these mesenteries are lost.
What is an example of a dorsal mesentery?
Dorsal mesogastrium
Dorsal mesoduodenum
Dorsal mesocolon
In Week 4, the (cranial / caudal) end of the oesophagus dilates to form which shapes of the stomach?
caudal
Greater and lesser curvatures
After its caudal dilation, in which direction does the gut tube project to form the stomach?
Dorsally (posteriorly)
By how many degrees does the gut tube rotate to form the stomach?
90º
Which structures, associated with the stomach, form after the rotation is complete?
Greater and lesser sacs
Greater and lesser omenta
Falciform ligament
Where in the duodenum does the foregut stop and the midgut begin?
Between the 2nd and 3rd parts
What is the septum transversum?
Developmental structure which gives rise to the diaphragm and ventral mesentery (lesser omentum, falciform ligament)
Derived from the mesoderm
The liver buds off the gut tube during development. Into which structure does it bud?
Septum transversum
Which organ buds off the endoderm of the gut tube into the mesoderm of the septum transversum?
Liver
Which germ layer forms the lining of the biliary tree?
Endoderm
During development, the pancreas has ___ buds.
two
At the beginning of its development, the pancreas buds off the gut tube in two places. What are these two buds called?
Ventral pancreatic bud
Dorsal pancreatic bud
The ventral pancreatic bud rotates ___ around the dorsal aspect of the gut tube and then ___ with the dorsal pancreatic bud.
180º
fuses
What is the embryological structure which eventually becomes the gall bladder?
Cystic diverticulum
During development, the pancreas moves from ___ to ___.
(retroperitoneal / intraperitoneal)
intraperitoneal to retroperitoneal
Does the spleen bud from the gut tube?
No
Which germ layer does the spleen come from?
Mesoderm
because it’s related to the VASCULAR system
During the majority of its development, the intestines are (inside / outside) the embryo.
outside
Main congenital GI tract defects to know:
Vitelline duct problems - Meckel’s diverticulum, cysts, ligaments and fistulae
Fistulae or blind ends elsewhere - urorectal, anal pits etc.
