Please enable JavaScript.
Coggle requires JavaScript to display documents.
Duodenopancreatic Block - Coggle Diagram
Duodenopancreatic Block
The pancreas is fitted into the duodenal "C-frame" like a tire on a rim across the L1–L2 vertebral level.
4 Pillars of Inseparability
Contiguity
Intimate physical embedding of the pancreatic head within the duodenal curve.
Vascularity
Shared common mesenteric arterial supply & venous drainage
Peritoneum
Shared retroperitoneal fixity (secondarily retroperitoneal)
Ductal Drainage
Shared biliary and pancreatic openings into D2
The Duodenum (Initial Small Intestine)
Deep, fixed (retroperitoneal), thick caliber (length: 25–30 cm). Lies across supramesocolic & inframesocolic compartments
D1 (Superior Part | 4–5 cm)
Extends from pyloric sphincter on right side of L1
Initial segment is dilated & mobile: Duodenal Bulb (Ampulla).
D2 (Descending Part | ~10 cm)
Forms superior flexure (genu superius, < 90°) with D1
Runs paravertebrally from L1 to L4
Entry site for bile and main/accessory pancreatic ducts
D4 (Ascending Part | ~4 cm)
Ascends vertically on left side of spine (L4 to L2)
Terminates at the Duodenojejunal Flexure (Angle of Treitz)
D3 (Horizontal Part | ~8 cm)
Forms inferior flexure (genu inferius, 90°) with D2; prevertebral segment at L3–L4
Crosses anterior to IVC & Aorta → vulnerable to crush injuries in trauma
The Pancreas & Ductal System
Morphology & Parts
Dimensions
Length
15–18 cm
Height
Head (6 cm)
Neck (3 cm)
Tail (1–2 cm)
Thickness
~2 cm
Anatomical Subdivisions
Body
Crosses midline superiorly and to the left
Tail
Tapered distal extremity reaching the splenic hilum
Neck (Isthmus)
Constricted band bridging head and body
Head
Nestled in duodenal curve; features posterior Uncinate Process (Small pancreas of Winslow) passing behind superior mesenteric vessels
Nature & Weight
Mixed gland (exocrine & endocrine); ~80 g; firm, granular, and friable
Ductal System (Excretory Pathways)
Main Pancreatic Duct (Wirsung)
Traverses entire gland
Merges with "Common Bile Duct" → "Hepatopancreatic Ampulla" (Ampulla of Vater)
Opens at "Major Duodenal Papilla" (Major Caruncle) in "D2"
Encircled by smooth muscle "Sphincter of Oddi"
Accessory Duct (Santorini)
Drains portion of pancreatic head
Opens ~2.5 cm above major papilla
Forms the "Minor Duodenal Papilla" (Minor Caruncle)