The Pancreas

Question 1

Describe the embryological origin of the pancreas.

Answer 1

Begins development in the 4th week from endoderm of the duodenum. Two pouches develop, the ventral and dorsal pancreas, which rotate and fuse by week 8.

Question 2

What are the three most common congenital anomalies of the pancreas?

Answer 2

1. Heterotopic pancreas
2. Pancreas divisim
3. Annular pancreas

Question 3

Describe Heterotopic pancreas.

Answer 3

Pancreatic tissue in the wrong anatomic position (e.g. within the stomach, duodenum, or Meckel’s diverticulum)

Question 4

Describe pancreas divisum.

Answer 4

Failure of the two developmental pancreatic ducts to fuse (normally the duct of Santorini becomes the main duct).

Question 5

What percent of the population is affected by pancreas divisum, and what are the consequences?

Answer 5

5%. Inadequate drainage results in chronic pain and recurrent bouts of pancreatitis.

Question 6

Describe annular pancreas, and what problems it can cause.

Answer 6

The situation in which the ventral pancreas malrotates and encircles the second portion of the duodenum. Can lead to pancreatitis, upper GI obstruction, and peptic ulcers.

Question 7

Describe the anatomic location of the pancreas.

Answer 7

A retroperitoneal organ that lies posterior to the stomach, transverse mesocolon and lesser omentum, at the level of L2.

Question 8

What are the different segments of the pancreas?

Answer 8

1. Head (including the uncinate process)
2. Neck (portion anterior to the SMV)
3. Body (forms posterior floor of lesser sac)
4. Tail (enters splenorenal ligament, adjacent to the splenic hilum

Question 9

What is the sphincter of Oddi?

Answer 9

The smooth muscle around the ampulla.

Question 10

What is the eponym for the main pancreatic duct? In what percent of the population does this fuse with the common bile duct to form the ampulla within the papilla of Vater?

Answer 10

Duct of Wirsung. Fuses with the CBD in 40% of the population for form the ampulla.

Question 11

What is the blood supply to the pancreas?

Answer 11

Head is supplied by anterior and posterior pancreaticoduodenal arteries.
Body and tail are supplied by branches of the dorsal pancreatic artery and splenic artery.

Question 12

What is the innervation to the pancreas?

Answer 12

Sympathetics are derived from the thoracic sympathetic ganglia to the spanchnic nerves (afferent) to the celiac ganglia (efferent, i.e. pain).