Pancreas: Function, Location, Diseases & Diagnosis

What Is Pancreas?

This is a patient information booklet detailing practical information about pancreas in general & specific information about pancreatic cancer. Its aim is to provide the patient & his or her family with useful information on this particular pancreatic problem, the procedures and tests you may need to undergo, various treatment approaches available with risks involved and helpful advice on coping successfully with the problem. If you require any further information or advice or are unsure about anything, Dr. D. R. Kulkarni or your own doctor will be able to help.

The pancreas is a solid gland attached in the back of the abdominal cavity behind the stomach. The pancreas is divided into 5 parts – the head, the uncinate process, the neck, the body and the tail. The head of the gland is closely attached to the duodenum, which is the first part of the small intestine into which the stomach empties liquids and partially digested food. The head of the gland is situated just to the right of the midline of the abdomen and below the right ribcage. The uncinate process is an extension of the lower part of the head of the gland, which surrounds important blood vessels. The body and tail of the pancreas lie at an angle so that the tail of the pancreas is situated beneath the extreme edge of the left rib cage. The tail of the gland is closely attached to the central part of the spleen & splenic blood vessels.

Running behind the neck and uncinate process are many important blood vessels which supply the liver, the rest of the gut organs and the kidneys, including the aorta (an artery) which takes all the blood to the lower abdomen and legs, and the inferior vena cava (a vein) which returns blood from these areas. The splenic vein runs immediately under the tail and body of the pancreas and joins with the portal vein that runs immediately under the neck of the pancreas.

In short, pancreas is a centrally located and very precariously connected to or is in very close contact with most of the important structures in the abdomen. Hence diseases affecting pancreas can inadvertently involve any one or more of these structures. Hence patients with pancreatic problems may not necessarily have pancreatic complaints, but can present with unrelated complaints.

Running along the length of the pancreas within its center is the main pancreatic duct, which empties pancreatic juice into the duodenum. Also running through the middle of the head of the pancreas is the main bile duct, which also empties into the duodenum. (The main bile duct carries bile from the liver where it is made and also from the gallbladder where it is stored). In most people the pancreatic duct and bile duct join together just before they open into the duodenum through a large fleshy nipple called the ampulla of Vater (after the person who described this).

Surrounding the openings of each of these ducts are small muscles that control the release of pancreatic juice and bile and thus act as valves (also called sphincters). There is also a valve that regulates the pancreatic juice and bile together and this sits in the ampulla. This common valve is called the sphincter of Oddi, also named after the man who described this.

About one in ten people have two separate pancreatic ducts, one that opens as normal through the ampulla of Vater and the other through a smaller nipple (called as papilla). For this reason the ampulla of Vater is sometimes called the major papilla and the other smaller opening is called the minor papilla. The pancreatic duct that opens through the minor papilla is called the accessory pancreatic duct (normally this joins the main pancreatic duct rather than opening separately into the duodenum).

What Does The Pancreas Do?

The pancreas does two important things:

• It makes enzymes, which are necessary to digest food in the intestines.

Food consists of carbohydrates (e.g. glucose), proteins (e.g. meat) and fat (e.g. butter). Pancreas secretes different enzymes, which are responsible for breaking down clumps of different types of food into small particles for absorption. (Process of digestion) The main enzymes include amylase for digesting carbohydrates, trypsin for digesting proteins and lipase for digesting fats.

These enzymes are collected from the small glands in the pancreas into small ducts and finally into the main pancreatic duct to be released into the duodenum. The enzymes when they are first made in the acini are not active (otherwise they would digest the pancreas as well!). When they pass into the duodenum however, they are made active by the juice of the duodenum.

If there are not enough pancreatic enzymes, fat is not digested and the stools (bowel motions) become pale and greasy. These greasy stools may become difficult to flush away from the toilet and may give off a strong offensive smell. Doctors call this steatorrhoea ( fatty stool.)

The digestion of fat is very special. Fat needs to be dispersed before the pancreatic enzymes can properly break it down. This dispersion of fats is made by bile acids, which are present in bile produced by the liver and stored in the gall bladder. Bile acids act in exactly the same way as detergents, which are used to wash up greasy dishes. Therefore, both bile acids and pancreatic enzymes are needed for fat digestion. If the main bile duct becomes blocked, then the bile cannot get into the duodenum & fat cannot be properly digested.

When this common opening is blocked, the bile made by the liver cannot go into the bowel it goes into the blood and out through the kidneys into the urine. This results in the eyes and skin becoming yellow and is known as jaundice. As the bile is in the urine this now becomes dark in color. Because the flow of bile is blocked (or obstructed), doctors call this condition obstructive jaundice. As the bile duct goes through the head of the pancreas, jaundice can be caused by disease of the pancreas (such as pancreatitis or cancer).

• It produces insulin to enable every part of the body to use glucose (sugar).

Insulin is a hormone made in special groups of cells called islets of Langerhans, which are dispersed throughout the pancreatic gland. It helps the cells of the body to use glucose as a source of energy in order to maintain their different functions. In absence of insulin, sugar instead of entering the cells of the body, stays in the blood leading to harmfully high concentrations. (Diabetes mellitus)

A large proportion of the islets (pronounced ‘eye- lets’) are in the tail of the gland. Most of the pancreas can be removed but there are usually enough islets remaining to make insulin sufficient to prevent sugar diabetes from occurring.

As you are probably aware, diabetes can be treated by taking regular injections of insulin, which can be taken from the pancreas of animals (e.g. pork insulin) or made by genetic engineering (so called ‘human’ insulin).

What Happens To Pancreatic Function In Pancreatic Diseases?

If pancreatic duct outflow is blocked due to any reason, gradually pancreatic duct enlarges in any size due to backpressure. Eventually the increased pressure within the duct starts taking toll on the pancreatic enzyme secretion, which drops and affects the digestion of food and absorption of nutrients, thereby affecting a person’s weight and overall health. The insulin production is not immediately affected but over a period it will also drop thereby causing sugar diabetes in the patient.

Enzyme production and insulin production are independent. Because digestive enzymes and insulin are made by different parts of the pancreas, a problem with enzyme production does not mean necessarily that there will be a problem with insulin production. Similarly, if there is a problem with insulin production, this does not mean necessarily that there will be a problem with enzyme production.

Assuming that the pancreas was normal to begin with, increasing loss of the pancreas gland (by disease or surgery) usually results in more loss of enzyme production before there is obvious loss of insulin production. Another way of saying this is that the insulin ‘reserve’ is much more than the enzyme ‘reserve’ of the pancreas.

Which Are Common Diseases Of Pancreas?

• Acute Pancreatitis
• Chronic Pancreatitis
• Pseudo cyst of pancreas
• Cancer of pancreas
• Cystic tumors
• Neuroendocrine tumors

What Special Investigations Are Done When A Problem Is Suspected With The Pancreas?

You may need to do some tests to find out more about your particular problem. Perhaps you’ve already undergone one or more of them.

You may be advised to have certain blood tests like complete blood count, blood urea, creatinine, liver function tests (bilirubin, liver enzymes like SGOT, SGPT, Alkaline phosphatase, gamma GT, albumin), amylase, lipase, calcium, and parathormone. In case of acute pancreatic problems you will be advised to get admitted and all these tests will then be done in-house.

Similarly diagnosis of pancreatic problems requires radiological imaging studies of abdomen like Ultrasonography, CT scan, MRI or further interventions like gastrointestinal endoscopy, ERCP, PTHC or EUS. It quite often so happens that patient is advised these investigations in a sequential manner and not at one go. This does take time but considering the cost of these investigations it is always better to ask for the next investigation only if it is absolutely necessary. Unfortunately in a small group of  patients one cannot reach a diagnosis in spite of all this effort.

Click here to learn more about: Pancreas: Function, Location, Diseases and Treatment.

If your doctor suspects you may have pancreatitis, you may be referred to a doctor who specializes in the digestive system.

Dr. D. R. KULKARNI
Gastrointestinal & Hepatopancreatobiliary Surgeon.

Dr. D. R. Kulkarni is an eminent Gastrointestinal & Hepatopancreatobiliary Surgeon in city of Mumbai, India. He has 24 years experience in the field of Gastrointestinal and Hepatopancreatobiliary Surgery. For Appointments call on : 9821046391 or click here to Book an appointment online