Head of the Pancreas

The head of the pancreas is the broad, rightmost portion of the pancreas that fits snugly into the C-shaped curve of the duodenum. It plays a central role in both digestive and hormonal regulation, housing parts of the main pancreatic duct and being closely associated with key vascular and biliary structures. Due to its deep retroperitoneal location and proximity to critical anatomy, it is a major focus in gastrointestinal imaging and pancreatic surgery.

Structure

The pancreatic head is flattened and somewhat triangular in shape when viewed in cross-section. It includes the main portion nestled in the duodenal curve as well as the uncinate process, a posterior projection that wraps around vascular structures. Internally, the head is rich in acinar cells that produce digestive enzymes and contains portions of the main and accessory pancreatic ducts.

Important internal features:

• Pancreatic acini: Exocrine units that produce enzyme-rich pancreatic juice.
• Main pancreatic duct (duct of Wirsung): Courses through the head toward the ampulla of Vater.
• Accessory duct (duct of Santorini): May be present and open separately into the duodenum.
• Scattered islets of Langerhans: Contribute to endocrine function, although less dense than in the tail.

Location

The head of the pancreas lies in the right upper quadrant of the abdomen and is retroperitoneal. It is surrounded by important anatomical structures:

Function

The head of the pancreas contributes to both exocrine and endocrine pancreatic functions:

• Exocrine function: Acinar cells produce digestive enzymes (amylase, lipase, proteases) which pass through ducts to enter the duodenum via the major duodenal papilla.
• Endocrine function: Scattered islets of Langerhans secrete hormones like insulin and glucagon, although these are more concentrated in the tail region.
• Ductal convergence: The head contains key portions of the ductal system that unite with the bile duct and influence duodenal content composition.

Clinical Significance

The pancreatic head is of prime importance in several clinical conditions:

• Pancreatic cancer: The most common site for pancreatic adenocarcinoma. Tumors here often compress the common bile duct, leading to obstructive jaundice — a classic early sign.
• Pancreatitis: Inflammation of the pancreas can localize to the head, causing pain, swelling, and duodenal compression.
• Whipple procedure (pancreaticoduodenectomy): A complex surgical operation that removes the pancreatic head, duodenum, and surrounding structures in cases of malignancy.
• Biliary obstruction: Because the common bile duct runs through or behind the head, masses or inflammation can obstruct bile flow and elevate bilirubin levels.
• Imaging landmark: The head is visualized in abdominal CT, MRI, and endoscopic ultrasound for diagnosis of lesions and planning interventions.

Due to its deep location and shared vasculature and ducts with surrounding structures, the head of the pancreas is involved in complex surgical and diagnostic decision-making. Early detection of pathology here is essential due to its association with life-threatening diseases such as pancreatic cancer.