Anatomy of PANCREAS

       The pancreas is a pale grey gland weighing about 60 grams. It is about 12–15 cm long and is situated in the epigastric and left hypochondriac regions of the abdominal cavity.It consists of abroad head, a body and a narrow tail. The head lies in the curve of the duodenum, the body behind the stomach and the tail lies in front of the left kidney and just reaches the spleen. The abdominal aorta and the inferior vena cava lie behind the gland.

Location and Structure:-

• Retroperitoneal organ located in the epigastrium and left hypochondrium.
• Shape: Elongated and tapered, resembling a fish.
• Parts:

1. Head: Lies in the curve of the duodenum, with the uncinate process extending behind the superior mesenteric vessels.
2. Neck: Connects the head and body, crossing the superior mesenteric vessels.
3. Body: The central part, lying across the midline, anterior to the aorta and left renal vein.
4. Tail: Narrow end extending to the splenic hilum, lying in the splenorenal ligament.
   

   

Relations

1. Anterior: Stomach, transverse colon, and transverse mesocolon.
2. Posterior: Inferior vena cava (IVC), aorta, left kidney, adrenal gland, and splenic vein.
3. Superior: Splenic artery and celiac trunk.
4. Inferior: Superior mesenteric artery and vein.

Vascular Supply

• Arterial Supply:

1. Head: Superior pancreaticoduodenal artery (branch of the gastroduodenal artery) and inferior pancreaticoduodenal artery (branch of the superior mesenteric artery).
2. Body and Tail: Branches from the splenic artery.

• Venous Drainage:

1. Corresponding veins drain into the portal vein system (splenic vein, superior mesenteric vein).

Ductal System

• Main pancreatic duct (Duct of Wirsung): Runs the length of the gland and opens into the duodenum at the major duodenal papilla (ampulla of Vater), shared with the common bile duct.
• Accessory pancreatic duct (Duct of Santorini): May drain into the duodenum independently at the minor duodenal papilla.

  

  Wirsung duct and Santorini duct 

  
  

Histology and Function

1)Exocrine Component:

• Acinar cells produce digestive enzymes (amylase, lipase, proteases).
• Ductal cells secrete bicarbonate to neutralize stomach acid.

2)Endocrine Component:Islets of Langerhans secrete hormones:

• Alpha cells: Glucagon (raises blood glucose).
• Beta cells: Insulin (lowers blood glucose).
• Delta cells: Somatostatin (regulates other pancreatic hormones).
• PP cells: Pancreatic polypeptide (regulates exocrine function).

Clinical Relevance

1. Pancreatitis: Inflammation of the pancreas, can be acute or chronic.
2. Pancreatic Cancer: Often occurs in the head, leading to jaundice from bile duct obstruction.
3. Diabetes Mellitus: Dysfunction of insulin secretion.
4. Congenital Anomalies: Pancreas divisum, annular pancreas.