What is Pancreas? Location And Diseases of Pancreas
Pancreas is one of the extrinsic glands of the digestive system. It has mixed endocrine and exocrine functions, and is present outside the wall of the digestive tract. In order to fully understand, "What is pancreas?" you must know its location, functions and diseases. The exocrine part secrets pancreatic juice into the duodenum; the juice contains a number of digestive enzymes and pro enzymes that help digest the food. The endocrine part produces hormones such as insulin that play significant role in the absorption, metabolism and storage of nutrients such as glucose. Dysfunction in the endocrine part of the pancreas leads to diabetes mellitus.
Location of Pancreas
A normal pancreas is about 12 to 15 cm long and weighs about 110 gm. Pancreas location is behind the stomach and it lies more or less transversely in the posterior wall of the abdomen; it has duodenum on its right and spleen on its left. It has a head that lies within the curvature of the duodenum, a neck that connects the head to the body and a body that blunts into its tail to touch the spleen. Cancer of the pancreas usually involves the head and accounts for most of the cases of extrahepatic biliary obstruction.
Functions of Pancreas
About 1500 ml of pancreatic juice is secreted everyday which contains many digestive enzymes, water and various ions such as bicarbonate, sodium, potassium.
- pH of the pancreatic juice is alkaline in nature which helps neutralize the gastric content entering the duodenum from the stomach.
- Pancreatic enzymes and pro-enzymes (zymogens) are essential for the digestion of protein, carbohydrate and fat constituents of food that we eat every day.
- Endocrine part of pancreas secrets two important hormones - insulin and glucagon - both of which are secreted reciprocally from pancreas and also act reciprocally in most circumstances. In a nutshell, insulin increases storage of glucose, fatty acids and amino acids. On the other hand glucagon is a catabolic hormone so it mobilizes glucose, fatty acids and amino acids from stores into the bloodstream.
Regulators of pancreatic secretion
Secretion of the pancreatic juice is primarily regulated by two hormones -
- Cholecystokinin (CCK)
Both of these hormones are produced by specialized cells of the duodenum. They are secreted in response to gastric acid entering the duodenum from the stomach and in response to products of protein and fat digestion (e.g. small peptides, amino acids and fatty acids). Both hormones act synergistically in response to a meal and cause a large volume of alkaline pancreatic juice rich in digestive enzymes to be released.
Diseases of pancreas
Pancreatitis is one of the troublesome pancreas diseases, and is characterized by inflammation which results from the activation of pancreatic enzymes within the pancreas that causes auto digestion of pancreatic tissues. The most common cause of pancreatitis is alcohol use in men and gallstones in women.
Carcinoma of the pancreas
Pancreatic cancer usually occurs after 50 years of age though most patients are between 60 to 80 years of age. It is slightly more common in men than in women. Cigarette smoking is the most common cause of this disease. Other risk factors include chronic pancreatitis, high saturated fat diet, diabetes mellitus, obesity and cirrhosis.
One of the reasons of deficient insulin action in diabetes mellitus can be due to a decrease in insulin secretion by the endocrine pancreas. Insulin deficiency causes hyperglycemia (chronically elevated glucose) which if left untreated can be fatal. In contrast, excessive insulin causes hypoglycemia (decreased blood glucose) which may lead to convulsion and coma. Glucagon deficiency can also cause hypoglycemia and excessive glucagon will worsen diabetes mellitus.