Pancreas and its disorders

Anatomy and structure

The human pancreas is located behind the peritoneum at the level of the first and second lumbar vertebrae. It is an accessory digestive gland which resembles the alphabet J in structure (present obliquely) in the abdominal cavity. Thier are many problems and disorders that can cause Pancreas to malfunction.

Structurally and anatomically, the pancreas is divided into head, neck, body and tail (from right to left). The head is present within the concavity of the duodenum whereas the tail of the pancreas lies in the hilum of the spleen.

Among disorder of Pancreas a very major problem is Pancreatitis and the treatment ranges from medicines to surgery.

Relations of Pancreas

The head of the pancreas is related anteriorly to the duodenum,colon and jejunum. Posterior to the head is the terminal part of renal veins, inferior vena cava, bile duct and right crus of diaphragm.This region of Pancreas is more prone to disorders like inflammation and Pancreatic obstructions.

Anteriorly, the neck or Pancreas is related to the peritoneum and pylorus. Whereas portal vein begins and superior mesenteric vessels terminate posterior to it.

Anterior to the body peritoneum, lesser sac and stomach are present. Posteriorly several structures are present which includes the aorta, left supra renal gland, left kidney, left renal vessels and splenic vein. To its inferior the left colic flexure is present.

The Tail is related to the splenic vessels within the gastric surface of the spleen and the spleno-renal ligament.

Blood supply Of Pancreas

Arterial supply to the kidney is provided mainly by the splenic artery which runs on its superior border. However, pancrearic arteries arise from both the gastroduodenal and superior mesenteric artery. The gastroduodenal provides anterior and posterior superior pancreatoduodenal arteries. On the other hand the anterior and posterior inferior pancreatoduodenal arteries are branches of the superior mesenteric artery.

Venous drainage occurs by means of pancreatic veins which drain into the splenic and the hepatic portal vein which eventually enter the splenic vein.  Any disorder or problem of Pancreas could lead to narrowing of arteries or veins which supply it with blood.

Histological stucture of Pancreas

The pancreas is surrounded by a thin layer of capsule comprising of connective tissue and blood vessels. Internal to the capsule are present numerous intralobular and interlobular excretory ducts. Acting as an exocrine gland, the serous acini of the gland secrete digestive juices. On the other hand, the endocrine part of the gland (Islets of langerhans) is responsible for the secretion of various hormones like insulin and glucagon.

Physiological function of the pancreas

The exocrine function of the pancreas is to produce pancreatic juice containing enzymes required for digestion like amylase and lipase which digest the ingested food particles.

To study the endocrine function of the pancreas, the islets of Langerhans are of extreme importance. The islets have 4 kinds of cells where each produces a completely different hormone for secretion into the blood. The Alpha cells produce Glucagon and Beta cells produce insulin. Both these hormones regulate blood glucose levels. Delta cells produce somatostatin. The PP cells produce pancreatic polypeptide.

Diseases and problems

  1. Accessory pancreatic tissue

    The most common locations for the presence of accessory pancreatic tissue is the stomach and duodenum where this tissue may contain the glucagon and insulin producing cells.

  2. Pancreatitis and Other Pancreas Problems

    One of the main reasons for this disease is the backing up of bile in the pancreatic duct. At times the spasm of the hepatopancreatic sphincter occurs to cause the entry of bile in the pancreatic duct which also causes pancreatitis.

    Pain caused due to inflammation of pancreas is poorly localised.It is referred to the epigastric region and might also be felt posterior to the paravertebral region and around the lower thoracic vertebrae.

    Pancreatitis may also cause compression of the superior mesenteric vessels present posterior to the body of pancreas. This may cause thrombosis of the vein or aneurysm of the artery.

  3. Carcinoma Of Pancreas

    Most often the pancreatic head is effected by tumors. As a result pressure is applied to the bile ducts pressure posterior to the head. This pressure causes the bile ducts to narrow and therefore lead to persistent obstructive jaundice. Other structures that may be compressed include portal vein or stomach leading to ascites and pyloric obstruction respectively.

  4. Annular pancreas

    This is a congenital abnormality which occurs in neonates during their development in the mothers womb. Ring like pancreatic tissue surrounds the duodenum to cause obstruction. This occurs primarily due to the formation of bifid ventral pancreatic bud in the development of the foregut and midgut.

  5. Pancreatic rupture Problem

    Even though the pancreas is centrally located and well protected it can be ruptured due to a several abdominal crushing injury like that of the impact of the steering wheel during a car accident. Rupture leads to the exposure and spread of the pancreatic juice to the adjacent regions leading to invasion. Eventual digestion of the tissues occurs which causes severe pain in the patient.