Body of Pancreas

The body of the pancreas is the elongated central portion of the pancreas located between the neck and tail. It extends toward the left across the posterior abdominal wall and lies predominantly within the epigastric region, with its lateral portion approaching the left hypochondrium.

Like most of the pancreas, the body is secondarily retroperitoneal. It lies posterior to the stomach and anterior to several major retroperitoneal structures, including the abdominal aorta, origin of the superior mesenteric artery, left crus of the diaphragm, left renal vessels, and left kidney.

The body contains both exocrine pancreatic tissue and endocrine pancreatic islets. The main pancreatic duct courses through the gland, generally from the tail toward the head, collecting secretions from numerous smaller ducts along its course.

Location

The body of the pancreas extends from the pancreatic neck toward the tail and crosses the posterior abdominal wall from right to left.

It is situated posterior to the stomach and anterior to major vessels and retroperitoneal organs.

Position Within the Pancreas

The pancreas is conventionally divided into the:

• Head
• Uncinate process
• Neck
• Body
• Tail

The body begins immediately to the left of the pancreatic neck and continues laterally until it narrows into the tail.

General Shape

The pancreatic body is elongated and somewhat triangular in cross-section.

This configuration allows three surfaces and three borders to be described anatomically.

Surfaces of the Pancreatic Body

The body of the pancreas is commonly described as having three surfaces:

• Anterior surface
• Posterior surface
• Inferior surface

Each surface has distinct relationships with surrounding abdominal structures.

Anterior Surface

The anterior surface of the pancreatic body faces anterosuperiorly and is related to the posterior wall of the stomach.

The stomach is not normally in direct contact with the pancreatic surface because the lesser sac lies between them.

Relationship to the Stomach

The stomach lies anterior to the pancreatic body.

The posterior surface of the stomach and anterior surface of the pancreas form important boundaries of the lesser sac region.

Lesser Sac

The lesser sac, or omental bursa, is a peritoneal recess located posterior to the stomach and anterior to the pancreas and neighboring retroperitoneal structures.

This relationship explains why pancreatic inflammation or fluid collections may extend into the lesser sac.

Posterior Surface

The posterior surface of the pancreatic body lies against the posterior abdominal wall and is related to several major vascular and retroperitoneal structures.

These relationships are particularly important in pancreatic surgery and cross-sectional imaging.

Posterior Relations

Structures related to the posterior aspect of the pancreatic body include:

• Abdominal aorta
• Origin of the superior mesenteric artery
• Left crus of the diaphragm
• Left renal vessels
• Left kidney
• Splenic vein

Relationship to the Aorta

The abdominal aorta lies posterior to the pancreatic body.

The close relationship between the pancreas and aorta is readily visible on axial CT and MRI.

Relationship to the Superior Mesenteric Artery

The superior mesenteric artery arises from the anterior aspect of the abdominal aorta behind the pancreas.

It passes anteriorly and inferiorly from its origin before entering the root of the mesentery.

Relationship to the Left Crus

The left crus of the diaphragm is related to the posterior aspect of the pancreatic body near the upper posterior abdominal wall.

Relationship to the Left Kidney

The left kidney lies posterior to the body and tail region of the pancreas.

The intervening fascial and retroperitoneal planes are important in the spread of pancreatic inflammation and in surgical approaches to the gland.

Relationship to the Left Renal Vessels

The left renal vein and associated renal vascular structures are closely related to the posterior aspect of the pancreas.

The left renal vein crosses anterior to the aorta and posterior to the superior mesenteric artery in the region inferior and posterior to the pancreas.

Relationship to the Splenic Vein

The splenic vein runs from left to right along the posterior aspect of the pancreas.

It is one of the most important vascular relationships of the pancreatic body and tail.

Splenic Vein Groove

The splenic vein may lie in a shallow groove along the posterior pancreatic surface.

Numerous small pancreatic veins drain directly into it.

Inferior Surface

The inferior surface of the pancreatic body faces inferoanteriorly.

It is related to structures including loops of jejunum and the region of the duodenojejunal junction.

Relationship to the Duodenojejunal Flexure

The duodenojejunal flexure lies inferior to the pancreatic body, particularly near its medial portion.

This region marks the transition between the duodenum and jejunum.

Relationship to Jejunal Loops

Proximal jejunal loops may lie inferior to the body of the pancreas.

Their precise position varies with intestinal filling and body position.

Borders of the Pancreatic Body

Because the pancreatic body is approximately triangular in cross-section, three borders are described:

• Superior border
• Anterior border
• Inferior border

Superior Border

The superior border separates the anterior and posterior surfaces of the pancreatic body.

It is closely associated with the splenic artery.

Splenic Artery

The splenic artery typically follows a tortuous course along the superior border of the pancreas toward the spleen.

It provides multiple pancreatic branches along its course.

Anterior Border

The anterior border separates the anterior and inferior surfaces.

The transverse mesocolon is attached along this general region of the pancreas.

Transverse Mesocolon

The transverse mesocolon is attached to the anterior aspect and border of the pancreas.

This relationship helps divide the peritoneal cavity into supracolic and infracolic compartments.

Inferior Border

The inferior border separates the posterior and inferior surfaces of the pancreatic body.

It lies above portions of the proximal small intestine and associated mesenteric structures.

Surface and Border Summary

Feature	Important Relationship
Anterior surface	Stomach, separated by lesser sac
Posterior surface	Aorta, left renal structures, splenic vein and posterior abdominal wall
Inferior surface	Duodenojejunal region and jejunal loops
Superior border	Splenic artery
Anterior border	Attachment of transverse mesocolon

Relationship to the Neck

The body begins immediately lateral to the neck of the pancreas.

The neck is a relatively short region lying anterior to the formation of the hepatic portal vein.

Relationship to the Tail

The pancreatic body gradually continues into the tail of the pancreas toward the left.

There is no sharply defined external boundary between the body and tail.

Retroperitoneal Position

The pancreatic body is generally classified as secondarily retroperitoneal.

During embryological development, the pancreas becomes closely applied to the posterior abdominal wall as its peritoneal relationships change.

Peritoneal Covering

The anterior aspect of the pancreatic body is covered by peritoneum associated with the posterior wall of the lesser sac.

Its posterior surface is fixed to the posterior abdominal wall and lacks a free peritoneal covering.

Pancreatic Parenchyma

The body consists of lobulated pancreatic parenchyma containing both exocrine and endocrine components.

Connective tissue septa subdivide the gland into lobules and carry vessels, nerves, and ducts.

Exocrine Pancreas

The majority of the pancreatic body consists of exocrine acinar tissue.

Acinar cells produce digestive enzymes that enter the pancreatic ductal system.

Pancreatic Acini

Pancreatic acini are clusters of secretory epithelial cells arranged around small lumina.

Their secretions pass into intercalated ducts and then through progressively larger ducts toward the main pancreatic duct.

Endocrine Pancreas

The endocrine component consists of the pancreatic islets, also called islets of Langerhans.

These clusters of endocrine cells release hormones directly into the bloodstream.

Main Pancreatic Duct

The main pancreatic duct, or duct of Wirsung, traverses the pancreatic body longitudinally.

It generally begins in the tail and travels toward the head while receiving numerous smaller tributary ducts.

Course Through the Body

Within the pancreatic body, the main pancreatic duct runs approximately along the long axis of the gland.

Numerous intralobular and interlobular ducts converge toward it.

Drainage Toward the Pancreatic Head

Secretions collected within the body pass through the main pancreatic duct toward the pancreatic head.

The duct usually joins the common bile duct near the duodenal wall before opening into the descending duodenum through the major duodenal papilla.

Accessory Pancreatic Duct

The accessory pancreatic duct, when present and patent, is principally associated with drainage pathways in the pancreatic head.

Its relationship to the body is less prominent than that of the main pancreatic duct.

Arterial Supply

The body of the pancreas receives arterial blood primarily from pancreatic branches of the splenic artery.

These branches form anastomotic networks within the gland.

Splenic Artery and Pancreatic Body

The splenic artery travels along the superior border of the pancreatic body and gives off multiple branches to the gland.

Its tortuous course is a characteristic anatomical relationship.

Dorsal Pancreatic Artery

The dorsal pancreatic artery is an important pancreatic vessel with variable origin.

It commonly arises from the splenic artery but may originate from other arteries of the celiac or superior mesenteric arterial systems.

Great Pancreatic Artery

The great pancreatic artery, also called the pancreatica magna, typically arises from the splenic artery and supplies a substantial portion of the pancreatic body and tail.

Inferior Pancreatic Artery

An inferior pancreatic artery may contribute to an arterial arcade along the inferior portion of the gland.

Its anatomy and origin are variable.

Arterial Supply Summary

Artery	Relationship to Pancreatic Body
Splenic artery	Runs along superior border and provides multiple pancreatic branches
Dorsal pancreatic artery	Variable vessel supplying pancreatic tissue
Great pancreatic artery	Important branch supplying body and tail
Inferior pancreatic artery	Variable contribution along inferior pancreas

Venous Drainage

Venous drainage from the pancreatic body occurs predominantly through pancreatic veins that empty into the splenic vein.

Additional channels communicate with the superior mesenteric and portal venous systems.

Pancreatic Veins

Numerous small pancreatic veins emerge from the gland and enter the splenic vein along its course behind the pancreas.

These veins ultimately deliver pancreatic venous blood to the hepatic portal circulation.

Portal Venous Drainage

Blood from the pancreatic body eventually enters the hepatic portal system.

It therefore passes through the liver before returning to the systemic venous circulation.

Lymphatic Drainage

Lymphatic vessels from the body of the pancreas generally follow pancreatic blood vessels toward regional lymph nodes.

Important drainage pathways include pancreaticosplenic nodes and nodes associated with the superior mesenteric and celiac vascular territories.

Pancreaticosplenic Lymph Nodes

Pancreaticosplenic lymph nodes lie along the splenic vessels near the superior border and posterior aspect of the pancreas.

They receive lymph from portions of the pancreatic body and tail.

Celiac Lymph Nodes

Lymph from pancreatic regional nodes ultimately communicates with lymphatic pathways associated with the celiac lymph nodes.

Innervation

The pancreas receives autonomic innervation through sympathetic and parasympathetic pathways associated with the celiac and superior mesenteric plexuses.

Nerve fibers accompany arteries into the pancreatic parenchyma.

Sympathetic Innervation

Sympathetic fibers reach the pancreas through abdominal autonomic plexuses, including the celiac plexus.

Visceral afferent fibers associated with pancreatic pain commonly travel centrally alongside sympathetic pathways.

Parasympathetic Innervation

Parasympathetic fibers are supplied primarily through the vagus nerve.

These fibers participate in regulation of pancreatic secretory activity.

Relationship to the Celiac Plexus

The celiac plexus lies posterior to the pancreas around the origin of the celiac trunk and neighboring major arteries.

The close anatomical relationship helps explain patterns of visceral pain associated with pancreatic disease.

Functions of the Pancreatic Body

The pancreatic body contributes to both major functions of the pancreas:

• Exocrine secretion of digestive enzymes and bicarbonate-rich fluid
• Endocrine secretion of hormones involved in metabolic regulation

Exocrine Function

Acinar cells produce digestive enzyme precursors and enzymes that are delivered through the ductal system into the duodenum.

Ductal cells contribute bicarbonate-rich fluid that helps neutralize acidic gastric contents entering the small intestine.

Endocrine Function

Pancreatic islets contain several endocrine cell populations that secrete hormones directly into the circulation.

These hormones include insulin, glucagon, somatostatin, and pancreatic polypeptide.

Body of Pancreas on CT

On axial CT imaging, the pancreatic body can be identified anterior to the aorta and major retroperitoneal vessels and posterior to the stomach.

The splenic vein is an important landmark running along its posterior aspect.

Body of Pancreas on MRI

MRI provides detailed visualization of pancreatic parenchyma, surrounding soft tissues, blood vessels, and the pancreatic ductal system.

Magnetic resonance cholangiopancreatography can provide additional noninvasive visualization of pancreatic and biliary ducts.

Ultrasound

The pancreatic body may be visualized with transabdominal ultrasound, although bowel gas and patient anatomy can limit assessment.

Major vascular structures posterior to the pancreas can serve as useful sonographic landmarks.

Endoscopic Ultrasound

Endoscopic ultrasound allows high-resolution imaging of the pancreas from the stomach and proximal duodenum.

The close relationship between the stomach and pancreatic body makes the body particularly accessible from a transgastric approach.

Pancreatitis

Pancreatitis is inflammation of pancreatic tissue and may involve the body alone or multiple regions of the gland.

Because the pancreas is retroperitoneal and lies adjacent to several fascial and peritoneal spaces, inflammatory fluid can spread beyond the gland.

Spread Into the Lesser Sac

Fluid associated with pancreatic inflammation may accumulate anterior to the pancreatic body within the lesser sac.

This reflects the close relationship between the pancreas and posterior wall of the omental bursa.

Pancreatic Pseudocyst

A pancreatic pseudocyst is an encapsulated collection containing pancreatic fluid that can develop following pancreatic inflammation or ductal disruption.

Pseudocysts related to the body may project into the lesser sac and produce mass effect on the stomach.

Pancreatic Tumors

Neoplasms can arise within the pancreatic body from ductal, acinar, endocrine, or other pancreatic tissues.

Their anatomical effects differ from lesions arising in the pancreatic head because of the body's different relationships with the bile duct, stomach, spleen, vessels, and retroperitoneum.

Body and Tail Tumors

Lesions of the body and tail generally do not obstruct the distal common bile duct as readily as tumors of the pancreatic head.

They may instead involve neighboring vessels, retroperitoneal tissues, stomach, spleen, or adjacent organs as they enlarge.

Vascular Involvement

Pancreatic body lesions may involve or encase nearby vascular structures, particularly the splenic artery, splenic vein, celiac arterial region, and superior mesenteric arterial origin.

Evaluation of these relationships is important when determining surgical anatomy.

Splenic Vein Thrombosis

Disease involving the pancreatic body or tail can affect the closely related splenic vein.

Inflammation, compression, or tumor invasion may contribute to splenic vein thrombosis.

Left-Sided Portal Hypertension

Splenic vein obstruction can increase venous pressure in tributaries draining toward the splenic venous system.

This can produce localized, or left-sided, portal hypertension and development of collateral venous pathways.

Pancreatic Trauma

The pancreatic body can be injured by significant blunt abdominal trauma.

Because the gland lies anterior to the vertebral column, compression of the pancreas against the spine can cause parenchymal or ductal injury.

Main Pancreatic Duct Injury

Damage to the main pancreatic duct is an important consideration in pancreatic trauma.

Duct disruption can permit pancreatic secretions to leak into surrounding tissues and spaces.

Distal Pancreatectomy

Distal pancreatectomy removes a portion of the pancreas to the left of a selected transection plane and commonly includes varying amounts of the body and tail.

Depending on the disease and surgical approach, the spleen may either be removed or preserved.

Relationship to Splenectomy

Because the splenic artery and vein are intimately associated with the body and tail of the pancreas, distal pancreatic surgery frequently requires careful management of the splenic vessels.

Some operations therefore include splenectomy, while selected procedures preserve the spleen.

Spleen-Preserving Distal Pancreatectomy

In selected patients, the distal pancreas may be removed while preserving the spleen.

This requires careful consideration of the splenic vessels or alternative collateral vascular pathways depending on the surgical technique.

Anterior Surgical Relationships

Access to the pancreatic body from the anterior abdomen generally requires approaching the gland behind the stomach.

The gastrocolic region and lesser sac provide important surgical routes to the anterior pancreatic surface.

Posterior Surgical Relationships

The posterior surface of the pancreatic body is closely related to major vessels and retroperitoneal structures.

Dissection in this plane therefore requires identification of the splenic vein, aorta, renal vessels, and neighboring vascular structures.

Body Versus Head of Pancreas

Feature	Body	Head
General position	Extends across posterior abdominal wall	Lies within duodenal curvature
Anterior relationship	Stomach across lesser sac	Transverse colon and nearby bowel structures
Major posterior vessel	Splenic vein along posterior surface	Major portal and caval relationships
Bile duct relationship	No intimate terminal bile duct relationship	Closely related to common bile duct
Major arterial association	Splenic artery	Pancreaticoduodenal arterial arcades

Body Versus Tail of Pancreas

Feature	Body	Tail
Position	Central elongated pancreatic portion	Left lateral terminal portion
Peritoneal relationship	Secondarily retroperitoneal	Extends within splenorenal ligament near spleen
Major posterior relation	Aorta, renal structures and splenic vein	Closely related to left kidney and splenic hilum
Continuity	Between neck and tail	Continuation of body toward spleen

Key Anatomical Relationships

Structure	Relationship to Pancreatic Body
Stomach	Anterior, separated by lesser sac
Splenic artery	Along superior border
Splenic vein	Along posterior surface
Aorta	Posterior
Superior mesenteric artery origin	Posterior to pancreas
Left kidney	Posterior
Left renal vessels	Posterior
Transverse mesocolon	Attached along anterior aspect/border
Jejunum	Inferior

Key Features of the Pancreatic Body

Feature	Key Point
Location	Between pancreatic neck and tail
Peritoneal position	Secondarily retroperitoneal
Shape	Elongated and approximately triangular in cross-section
Surfaces	Anterior, posterior and inferior
Borders	Superior, anterior and inferior
Major anterior relation	Stomach across lesser sac
Major arterial relation	Splenic artery along superior border
Major venous relation	Splenic vein along posterior surface
Main duct	Main pancreatic duct
Primary arterial supply	Pancreatic branches of splenic artery
Venous drainage	Predominantly into splenic vein and portal system

Anatomical and Clinical Importance

The body of the pancreas occupies a central position within the upper retroperitoneum and has important relationships with the stomach, lesser sac, splenic vessels, aorta, renal vessels, left kidney, transverse mesocolon, and proximal small intestine. Its triangular configuration allows anterior, posterior, and inferior surfaces and corresponding borders to be identified.

The splenic artery courses along the superior border of the body, while the splenic vein lies closely applied to its posterior surface. The main pancreatic duct passes longitudinally through the gland and collects exocrine secretions as it travels toward the pancreatic head.

These relationships are clinically important in pancreatitis, pancreatic tumors, splenic vein thrombosis, abdominal trauma, and distal pancreatectomy. Detailed understanding of the vascular and retroperitoneal anatomy of the pancreatic body is also essential for interpreting CT, MRI, ultrasound, and endoscopic ultrasound examinations of the pancreas.