Pancreas & Small Bowel

Question 1

Which artery and vein passes through the pancreas?

Answer 1

-superior mesenteric

Question 2

What is the pancreas imaged?

Answer 2

• MRCP -type of MRI
• angiography- wire into femural artery in groin->aorta -> coeliac axis, superior mesenteric artery, common hepatic artery, embolisation of gasproduodenal artery

Question 3

What is endocrine vs exocrine secretion?

Answer 3

Endocrine:
-secretion into the blood stream to have effect on distant target organ (autocrine/paracrine) -ductless glands

Exocrine:
-secretion into a duct to have direct local effect

Question 4

What are the main endocrine secretion of the pancreas and their actions?

Answer 4

Insulin:

• promotes glucose transport into cells & storage as glycogen
• decreases blood glucose
• promotes protein synthesis & lipogenesis

Glucagon:
-increases gluconeogenesis & glycogenolysis (increases blood glucose)

Somatostatin

• endocrine cynaide
• inhibits everything (used in operations)

Question 5

Compare and contrast endocrine and exocrine secretion in the pancreas.

Answer 5

Endocrine- 2% of gland:

• islets of Langerhans
• secretes hormones into blood (insulin, glucagon, somatostatin, pancreatic polypeptide)
• regulation of blood glucose, metabolism & growth effects

Exocrine- 98% of gland:

• secretes pancreatic juice into duodenum via MPD/sphincter of Oddi/ampulla
• digestive function

Question 6

What is pancreatic cell differentiation?

Answer 6

Acini:

• attached to ducts
• grape-like cluster of secretory units
• acinar cells secrete pro-enzymes into ducts

Islets:

• derived from the branching duct system
• lose contact with duct- become islet
• differentiate into a and B cells secreting into blood
• more in tail than head

Question 7

Microanatomy- screenshots

Answer 7

• centroacinar cells

- pancreatic acinar cells

Question 8

What is the composition of islets?

Answer 8

Alpha-cells:
-15-20% of islet tissue and secrete glucagon

Beta-cells:
-60-70% of islet tissue and secrete insulin

Delta cells:

• 5-10% of islet tissue
• secrete somatostatin

Acini surrounds it
-islets are highly vascular so all endocrine cells have close site for secretion

Question 9

What is the composition of islets?

Answer 9

Alpha-cells:
-15-20% of islet tissue and secrete glucagon

Beta-cells:
-60-70% of islet tissue and secrete insulin

Delta cells:

• 5-10% of islet tissue
• secrete somatostatin

Acini surrounds it
-islets are highly vascular so all endocrine cells have close site for secretion

Question 10

What is the composition of Acini?

Answer 10

Secretory acinar cells:
-large with apical secretion granules

Duct cells:
-small & pale

-secrete pancreatic enzymes