GI Embryology Flashcards
Which of the 3 embryonic germ layers gives rise to the gut tube epithelium?
Endoderm
Which of the 3 embryonic germ layers gives rise to the accessory glands (liver, pancreas?
Endoderm
Which embryonic germ layer gives rise to…
During the 4th week, the primitive gut tube develops and becomes surrounded by..
intraembryonic coelom (body cavity)
Communication between GI tract and ..? will obliterate…?
Anterior attachment
Ventral mesentery
Posterior attachment
Dorsal mesentery
The dorsal and ventral mesentery are present in…
foregut
The ventral mesentery is no longer present in…
midgut and hindgut
Falciform ligament??
Connection of stomach to… derives from
?
Name the adult foregut derivatives
The adult foregut is supplied by…
celiac trunk
In adult humans there is no connection between the GI tract and the outside of the body other than the mouth and rectus. However, if these connections aren’t obliterated correctly, they can lead to congenital malformations
Incomplete recanalization of the esophagus leads to…
stenosis of the esophagus
This inappropriate recanalization leading to stenosis can occur anywhere along the GI tract during development
Fistula? Septum?
Describe the 2 rotational processes of the stomach
Anterior part rotates to form the anterior part of the stomach (lesser curve).
All the organs the stomach is attached to will experience movement as the stomach rotate! This is why…
How does the liver and spleen move when the stomach rotates?
Liver: Moves to the right side of the body
Spleen: Moves to the left side of the body
Stomach rotation causes the duodenum to…
?
Liver bud originates from…
the duodenum
The pancreas originates as 2 structures called…
ventral and dorsal pancreatic buds
Describe the formation of the pancreas
Ventral bud migrates posteriorly around duodenum to fuse with dorsal bud
What happens if pancreatic buds do not fuse during development?
The person will have an accessory pancreas (2 pancreases)
The gastrosplenic ligament and splenic..? is a remnant of…
? mesentery
Stenosis vs Atresia
Stenosis: Incomplete recanalization of gut tube lumen (narrowing)
Atresia: Failure of lumen recanalization
What supplies blood to the midgut?
SMA
As it grows, the midgut forms a ventral…
U-shaped loop (midgut loop)
What do we call the process of the midgut extending into the …?
herniation
Retraction of midgut is due to…
?
During process of retraction, another process of fixation occurs. Define fixation
Fusion of ascending and descending colon with posterior peritoneum, rendering them secondarily retroperitoneal.
Fusion of mesentery of transverse colon…
What are omphaloceles?
Failure of midgut to retract to abdominal cavity
What is an umbilical hernia?
Midgut returns to abdominal cavity but later herniates (due to incomplete closure of umbilical ring or defects in anterior abdominal wall).
What is an Ileal (Meckel’s) diverticulum?
What can cause situs inversus
Abnormal gut rotation…??
How will situs inversus alter appendix location?
Blood supply of the hindgut
IMA
Hindgut originates from a structure called
cloaca
In placental mammals, the cloaca undergoes
partitioning (to form 2 orifices)
What is the acutaneous line?
Histological structure (marks transition from columner epithelium to stratified squamous epithelium)
What is the pectinate line?
Where endoderm of hindgut meets…?
What is a fistula?
Anal atresia
