Embryology: The Digestive System Flashcards
When does the primordial gut form?
4th week
What arises as outgrowths from the distal part of the foregut?
Liver
Gallbladder
Pancreas
Biliary System
What is the cause of most anorectal anomalies?
They result from abnormal partitioning of the cloaca into the rectum and anal canal posteriorly and the urinary bladder and urethra anteriorly
What is the embryonic tissue origin of most of the gastrointestinal tract?
Endoderm
What closes the cranial end of the primordial gut?
Oropharyngeal Membrane
What closes the caudal end of the primordial gut?
Cloacal Membrane
What suspends the gut tube throughout the entire length from the posterior abdominal wall?
Dorsal Mesentery
Where is the ventral mesentery found and what is its fate?
Only in the foregut and it eventually becomes the falciform ligament and the lesser omentum.
What are the effects of stomach rotation on the duodenum?
It all becomes retroperitoneal except for the 1st part, which is connected to the ventral mesentery
How does the pancreas develop?
The pancreas develops from pancreatic buds from the endodermal lining of the foregut. When the duodenum rotates to the right, the ventral pancreatic bud moves dorsally and fuses with the dorsal pancreatic bud.
What does the ventral pancreatic bud form?
Most of the head of the pancreas and the uncinate process
What does the dorsal pancreatic bud form?
The remainder of the pancreas besides the head and uncinate process
What embryological structure develops into the liver?
Hepatic Diverticulum
What other structures does the hepatic diverticulum develop into?
In addition to the liver, it also turns into the gall bladder and biliary duct system
What happens to the umbilical loop of the intestine in the midgut during the 6th week of development?
It herniates into the umbilical cord and it rotates 90 degrees counterclockwise because there is no room in the abdomen. In the 10th week, it rotates another 180 degrees counterclockwise and returns to the abdomen.
