Topic 1: Gastrointestinal Physiology and Disease

What makes up the Pancreas?

• Exocrine Pancreas ( Secrete into ducts)

• Endocrine Pancreas (Secrete straight into bloodstream)

Label the Pancreas?

What is the Exocrine Pancreas?

• makes up 85-90% of the pancreas

• made up of acinar cells

• produces digestive enzymes (Zymogens) and alkaline fluid

• secretes fluid into the duodenum via the pancreatic ducts

made up of:

• Acini

• Ducts

What is the endocrine Pancreas?

• makes up 10 - 15% of the pancreatic mass

• consist of islet of Langerhans cells that create and release hormones directly into bloodstream.

• Hormones include:

- Insulin

- Glucagon

- Somatostatin

What make up the Exocrine Pancreas?

• Made up of the acinar cells

  • epithelial cells that make and secrete digestive enzymes. Come together in lobules

What makes up the Exo Pancreas Ducts?

• Ducts

  • Intercalated ducts → smallest and start at the acinus

  • Intralobular ducts → drain several acini in a lobule

  • Interlobular ducts → run between the lobules

  • Main Pancreatic Duct → runs the entire pancreas and collects fluid from all the interlobular ducts.

  • Duodenum

Path of the pancreatic juice from main pancreatic duct to duodenum: Main Pancreatic Duct + Bile Duct → [?] → opening at [?] → controlled by [?]

Main Pancreatic Duct + Common Bile Duct → Ampulla of Vater → Opening at the Duodenal Papilla → Controlled by the Sphincter of Oddi

What is the Ampulla of Vater

• main union of the main pancreatic duct and bile duct

• where bile and pancreatic juice mix before enter SI

• can be found in the wall of the descending duodenum

What is the Duodenal Papilla?

• rounded fold of mucous membrane on the duodenal wall

• physical opening for the ampulla of Vater fluid to drain into the SI

What is the Sphincter of Oddi

• smooth muscular valve that surround the end of the bile duct, pancreatic duct and the ampulla

• It had three main functions:

  • regulates the flow of the bile and pancreatic secretions into the duodenum by relaxing to the hormone CCK

  • prevents the backflow of the duodenal contents (stomach acid) into the pancreatic duct

What is the primary mechanism behind ma