The pancreas is an abdominal glandular organ with both digestive (exocrine) and hormonal (endocrine) functions. In this article, we shall look at the anatomy of the pancreas – its structure, anatomical position and neurovascular supply.
The pancreas is an oblong-shaped organ located at the level of the transpyloric plane (L1). With the exception of the tail of the pancreas, it is a retroperitoneal organ, situated deep within the upper abdomen in the epigastrium and left hypochondrium regions. In terms of its anatomical relations to other structures, the pancreas lies close to the stomach, spleen, duodenum, transverse mesocolon, common bile duct, and several major vessels.
The stomach and pylorus lie anterior to the pancreas and are separated from it by the lesser sac. The C shaped duodenum curves around and outlines the head of the pancreas, with the first part of the duodenum lying anteriorly and the second part lying laterally to the right of the pancreatic head. The transverse mesocolon attaches to the anterior surface of the pancreas, while the common bile duct descends behind the head of the pancreas, opening into the second part of the duodenum alongside the major pancreatic duct and through the major duodenal papilla. The spleen is situated posteriorly and laterally to the pancreas, and the lienorenal ligament is formed from peritoneum and connects the spleen to the tail of the pancreas.
In terms of vascular anatomy, the aorta and inferior vena cava pass posteriorly to the head of the pancreas. The superior mesenteric artery lies behind the neck of the pancreas and anterior to the uncinate process. Posterior to the neck of the pancreas, the splenic and superior mesenteric veins unite to form the hepatic portal vein. As it travels from its origin at the celiac plexus towards the splenic hilum, the splenic artery traverses the superior border of the pancreas.
The pancreas generally is divided into five parts: the head (the widest part of the pancreas), the uncinate process (a projection arising from the lower part of the head), the neck (positioned between the head and the body of the pancreas), the body (centrally located, crossing the midline of the human body to lie behind the stomach and to the left of the superior mesenteric vessels), and the tail (the left end of the pancreas which lies within close proximity to the hilum of the spleen). The tail is the only part of the pancreas that is intraperitoneal.
In terms of its duct system, the exocrine pancreas is classified as a lobulated, serous gland which produces digestive enzyme precursors. It is composed of approximately one million ‘berry-like’ clusters of cells called acini, connected by short intercalated ducts. These intercalated ducts unite with those draining adjacent lobules and channel into a network of intralobular collecting ducts, which in turn drain into the main pancreatic duct. This main pancreatic duct runs the length of the pancreas and unites with the common bile duct, forming the hepatopancreatic ampulla of Vater. This structure then opens into the duodenum through the major duodenal papilla.
The secretions into the duodenum are regulated by a muscular valve – the sphincter of Oddi. This valve surrounds the ampulla of Vater, acting as a gatekeeper and ensuring that the release of digestive enzymes and bile into the duodenum is properly controlled.
The pancreas is a vital organ located in the abdomen, behind the stomach and near several major vessels and significant landmarks in vascular anatomy. The pancreas is typically divided into five parts - the head, uncinate process, neck, body, and tail - and surrounded by the duodenum, transverse mesocolon, common bile duct, and spleen. The pancreas is supplied by the pancreatic branches of the splenic artery, while the head of the pancreas is also supplied by the superior and inferior pancreaticoduodenal arteries. Venous drainage of the head of the pancreas is into the superior mesenteric branches of the hepatic portal vein, with the pancreatic veins draining the rest of the pancreas via the splenic vein.
The exocrine pancreas is classified as a lobulated, serous gland which produces digestive enzyme precursors. It is composed of approximately one million ‘berry-like’ clusters of cells called acini, connected by short intercalated ducts which unite with those draining adjacent lobules and drain into a network of intralobular collecting ducts. The pancreatic duct runs the length of the pancreas and unites with the common bile duct, forming the hepatopancreatic ampulla of Vater, which opens into the duodenum via the major duodenal papilla. Secretions into the duodenum are controlled by the sphincter of Oddi, which surrounds the ampulla of Vater to act as a valve.
The pancreas is drained by lymphatic vessels that follow the arterial supply. They empty into the pancreaticosplenal nodes and the pyloric nodes, which in turn drain into the superior mesenteric and coeliac lymph nodes.
Pancreatitis is an inflammation of the pancreas that can be acute or persistent. It is associated with severe epigastric pain which often radiates to the back, nausea, vomiting and diarrhoea. The causes of pancreatitis can be remembered using the mnemonic - GET SMASHED - Gall stones, Ethanol, Trauma, Steroids, Mumps, Autoimmune, Scorpion stings, Hypertriglyceridemia, hypercalcaemia and hyperparathyroidism, ERCP (endoscopic retrograde cholangiopancreatography), and Drugs (such as sodium valproate, azathioprine and sulphonamides).
Treatment for pancreatitis involves supportive measures such as IV fluids and analgesia, as well as addressing the underlying cause. Antibiotics are rarely required, as most cases are not due to infection.
The pancreas is an elongated, flattened gland located in the abdomen, posterior to the stomach and anterior to the vertebral column. It is situated in the epigastric and left hypochondriac regions of the abdomen, along the curve of the duodenum. The pancreas is composed of exocrine and endocrine components that play important roles in the body's homeostasis. Thus, it is highly vital to understand the pancreas' anatomy and functions in order to maintain homeostasis in the body.
Anatomically, the pancreas is divided into three distinct parts: the head, body, and tail. The head of the pancreas is located in the proximal part of the abdomen and rests at the opening of the duodenum, while the tail is situated in the hilum of the spleen. The pancreas is richly supplied with blood vessels and lymphatics, including the splenic artery and its branches.
The pancreas is composed of two components: the exocrine and endocrine components. The exocrine component is responsible for the secretion of digestive enzymes into the duodenum and consists of numerous ducts connected to the main and accessory pancreatic duct systems. Meanwhile, the endocrine component secretes hormones such as insulin and glucagon, both of which are essential for the maintenance of normal blood sugar levels.
Pancreatitis is an inflammation of the pancreas which can be triggered by a variety of factors, such as alcohol abuse, gallbladder disease, and autoimmune disorders. Common symptoms of pancreatitis include abdominal pain, nausea, vomiting, and fever. Treatment of pancreatitis involves supportive care, antibiotics, and, in some cases, surgery.
The pancreas plays an integral role in the body's homeostasis and is composed of two components—exocrine and endocrine—each of which is vital for the body's well-being. Allegations of pancreatitis must be taken seriously, considering the seriousness of its symptoms and the potential danger it poses. Appropriate and timely treatment through a combination of supportive care, antibiotics, and surgery is the best way to ensure that the condition does not worsen.
