The pancrease is a mixed exocrine & endocrine gland.
- lies tranversely in the posterior abdominal wall
- L1-L2 level
- Retroperitoneal (outside peritoneal cavity)
- Divided into
- head
- neck
- body
- tail
Important relations
- Head
- lies in the C-shaped concavity of the duodenum
- IVC & bile duct lie behind the head
- Neck
- portal vein behind the neck
- Body
- aorta, left renal artery and left suprarenal artery are behind the body
- Tail
- left kidney is behind the tail
- related to splenic hilum
Duct system
- Main pancreatic duct
- extends from the tail to the head
- joins the bile duct (green) to form the hepatopancreatic ampulla
- also known as ampulla of vater
- occasionally both ducts open separately
- opens into the descending part of duodenum
- at major duodenal papilla
- Accessory duct when present communicate with the main pancreatic duct
- opens to minor duodenal papilla
Smooth muscle sphincters control the flow of bile & pancreatic fluid into the duodenum
- Pancreatic duct sphincter
- Bile duct sphincter
- Hepatopancreatic sphincter (of Oddi)
Blood supply
Review & confirm again next time.
- From splenic artery
- branch: coeliac artery
- branch: Common hepatic artery
- From gastroduodenal artery
- branch: superior pancreatico-duodenal artery
- From superior mesenteric artery
- branch: inferior pancreatico-duodenal artery
Venous drainage
Veins accompanies the arteries and then drains to
- Splenic artery
- Superior mesenteric vein
Both joins the portal vein and enters the liver.
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Exocrine pancreas
- arranged as acini
- intercalated ducts penetrate the acini
- around the acini are basement membranes
- Acinar cells have zymogen molecules
- proteases
- lipase
- amylases
Endocrine pancreas
- rounded clusters of cells arranged as islets
- islet of Langerhans
- islets arranged as cords & clumps
- over a million islets
- more abundant in tail region
- In between islets have capillaries
- drain hormones into it
Four types of islet cells
1. A (alpha) – most abundant
- Glucagon: increases bloog glucose by glycogenolysis, lipolysis & gluconeogenesis
2. B (beta)
- Insulin: reduces blood glucose
3. D (delta)
- Somatostatin: inhibits release of other islet cell hormones
4. F
- pancreatic polypeptides: controls gastric secretions
I think the most abundant cell in the islet of langerhans are the Beta cells.
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