HeadThe duodenum curves round the head. The common bile duct passes behind it to join the pancreatic duct.
NeckThe neck separates the head from the body. The portal vein is formed just behind it.
BodyThe body runs from the neck toward the spleen. The pancreatic duct runs along inside it.
TailThe tail ends next to the spleen.
Uncinate processIt reaches behind the superior mesenteric vein. Uncinate means hooked.
Pancreatic ductIt carries pancreatic juice to the duodenum. It joins the common bile duct just before their shared opening. Also called the main pancreatic duct.
Accessory pancreatic ductWhere it is present it opens into the duodenum by itself. That is above the opening of the main duct. Also called the duct of Santorini.
DuodenumPancreatic juice and bile enter the duodenum here through a shared opening.
A drawn section 6
Pancreatic isletThe islets are the endocrine part of the pancreas. They are small islands of cells scattered among the acini. Formerly called islets of Langerhans.
Beta cellsBeta cells make the hormone insulin. A rise in blood glucose makes them release it.
Alpha cellsAlpha cells make the hormone glucagon. Low blood glucose makes them release it.
Delta cellsDelta cells make the hormone somatostatin.
AcinusEach acinus is a cluster of acinar cells round a small space. The cells secrete enzyme-rich pancreatic juice. The plural is acini.
Intercalated ductThe acinar cells secrete into these small ducts. These join larger and larger ducts on the way to the pancreatic duct.
How this list was compiled: Every name and detail checked on 2026-09-30 against OpenStax Anatomy and Physiology 2e, section 23.6 Accessory Organs in Digestion (head, body, tail, acini and acinar cells, the pancreatic duct, the accessory duct and the shared opening with the common bile duct), https://openstax.org/books/anatomy-and-physiology-2e/pages/23-6-accessory-organs-in-digestion-the-liver-pancreas-and-gallbladder, and section 17.9 The Endocrine Pancreas (the islets and their alpha, beta and delta cells), https://openstax.org/books/anatomy-and-physiology-2e/pages/17-9-the-endocrine-pancreas; against Wikipedia, Pancreas, Pancreatic duct and Pancreatic islets, text only; and, for the neck, the uncinate process and the intercalated ducts, TeachMeAnatomy, The Pancreas, https://teachmeanatomy.info/abdomen/viscera/pancreas/. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. The section is a drawing, not a photograph. Licence: own work
How it works
The first drawing shows the pancreas from the front with its ducts. The second is a section of the gland, drawn in the style of a stained slide, not photographed: one islet among the acini.
Read the full guide
The gland, then its two kinds of tissue
Numbers 1 to 5 are the regions of the gland, 6 and 7 its two ducts, and 8 the duodenum they empty into. In the section, number 9 is an islet, the endocrine tissue, and 10 to 12 are its cells, drawn in three tints. Numbers 13 and 14 are the exocrine tissue: an acinus and the small duct that drains it.
In the islet, count: beta cells are the most numerous, alpha cells come second, delta cells are scarce.
Islets are the pale islands; the acini round them make up most of the gland.
Questions and answers
What are the parts of the pancreas?
A head held in the curve of the duodenum, a short neck, a long body and a tapering tail that ends next to the spleen. A small uncinate process hooks off the lower part of the head.
What do alpha and beta cells make?
Alpha cells make glucagon, released when blood glucose is low. Beta cells make insulin, released when blood glucose rises. Delta cells make somatostatin. All three sit in the pancreatic islets.
What is the difference between an acinus and an islet?
An acinus is exocrine tissue: a cluster of acinar cells that secrete pancreatic juice into ducts. An islet is endocrine tissue: a cluster of cells that release hormones into the blood.
Where does the pancreatic duct open?
Into the duodenum. It joins the common bile duct just before a shared opening, the hepatopancreatic ampulla. A smaller accessory duct, where present, opens into the duodenum above it.