Development of the Digestive System

Question 1

where does the spleen develop?

Answer 1

in the dorsal mesogastrium

Question 2

where does the pancreas develop?

Answer 2

in the dorsal mesograstrium

Question 3

where does the liver develop?

Answer 3

in the ventral mesogastrium

Question 4

what is the duodenum? what are its main characteristics?

Answer 4

• the first portion of the small intestine
• it is the shortest part (20-25) and less mobile (since mostly secondarily retroperitoneal)
• C-shaped, mostly to the right
• its upper portion comes from: the foregut; and its lower potion: from the midgut
• pancreas, liver and biliary tree come from its upper (foregut) portion, from its budding and some invaginations

Question 5

the pancreas is…

Answer 5

a secondarily retroperitoneal organ

Question 6

what type of gland is the pancreas?

Answer 6

both endocrine and exocrine

Question 7

explain the development of the pancreas

Answer 7

• dorsal pancreatic bud → from the (foregut portion) duodenum
• ventral pancreatic bud → from the biliary tree
• while it is developing, since the foregut portion of the duodenum is attached to the stomach, it develops between the two layers of the dorsal mesograstrium
• it originates from the fusion of a dorsal bud and ventral bud during the repositioning of the duodenum

Question 8

what is developed from the foregut half of the duodenum:

Answer 8

1. liver bud (hepatic diverticulum)
   - hepatic cords
   - buds of gallbladder and biliary ducts
   - ventral pancreatic bud
2. dorsal pancreatic bud