The Pancreas and its functions

What is the Pancreas?

The pancreas is a leaf-shaped gland present in the upper-left part of the abdomen and behind the stomach. The pancreas is spongy, 6 to 10 inches long, stretching across the abdomen and surrounded by stomach, small-intestine, liver and spleen.

Anatomy of the Pancreas

The pancreas can be divided into head, neck, body and tail. Glandular tissue and a network of ducts extend across the length of the pancreas similar to the veins on a leaf. The central duct or main vein of the leaf is called the pancreatic-duct. In addition to the glandular tissue, there are clusters of tissue, that look like a bunch of grapes, called ‘Islet of Langerhans’ distributed throughout the pancreas.

The head, or the base of the leaf, is the largest part of the pancreas. It is located behind the stomach where the stomach meets the first part of the small-intestine called the duodenum. The pancreatic-duct drains into the duodenum. The bile-duct coming from the liver joins the pancreatic-duct at the duodenum creating a junction called as ‘ampulla of Vater’. This way, both the bile juice and pancreatic juice drain into the duodenum, to aid the digestion process.

The pancreas is surrounded by several, major blood-vessels such as superior mesenteric artery, superior mesenteric vein, portal vein and celiac axis. These supply blood to the pancreas and other abdominal organs.

Roles and Functions

The pancreas has two distinct functions:

A. An exocrine function which helps release enzymes into the digestive tract. The glandular tissues, form 95% of the pancreatic anatomy, secreting around 1 liter of clear, alkaline juice per day (in a healthy person) that contains pancreatic enzymes. There are 3 such enzymes:

Protease: There are 2 proteases called trypsin and chymotrypsin that help break-down or digest proteins. This is important as undigested protein can cause allergies in some people. Protease also protects us from certain bacteria and yeast that live in our gut.
Amylase: This breaks down carbohydrates or starches into sugars that our body cells require as energy. Not having enough amylase causes carbohydrates to be incompletely digested which can trigger diarrhea.
Lipase: The bile from the liver, and this enzyme, together help break-down or digest fats. If there is not enough lipase, absorption of fat and fat-soluble vitamins like A, D, E and K do not happen properly. This causes diarrhea and fatty-stools in some people.

B. An endocrine function which helps release hormones into the blood. The Islet of Langerhans secretes 4 hormones which are transported through the blood to other parts of the digestive system.

Insulin: Beta cells which make up 75% of the islet of Langerhans secrete insulin. Insulin helps the body utilize the sugar in the blood for energy. When the pancreas is not producing enough insulin, blood sugar levels rise and the person can develop diabetes.
Glucagon: Alpha cells that make up around 20% of the islet of Langerhans secrete glucagon. When blood sugar gets too low, glucagon raises the same by signaling the liver to release sugar which is always stored there as a backup in case food is not available.
Gastrin: A major part of the gastrin is produced by the G cells in the stomach, while a small part is secreted by the pancreas. Gastrin is critical to digestion as it stimulates the stomach to make gastric acid.
Amylin: This is also produced by the beta cells and help control stomach emptying, and hence – appetite.

Diseases and Disorders

The pancreas may be a small gland but is very significant in function, and is also vulnerable to many conditions.

Diabetes: Diabetes Mellitus is a common condition today and produces a range of symptoms such as frequent urination, excessive thirst, constant fatigue for no reason, losing weight for no reason, blurred vision, swelling or sensitivity in gums and a tingling sensations in the hands and feet. Again, diabetes is of 2 types:

Type 1: Here, the body’s immune system for no reason attacks the beta cells in the pancreas and tries to destroy them, causing reduced production of insulin. Viruses and genetic causes are attributed to this.
Type 2: In this, the body’s cells, muscles and liver are not able to efficiently use the sugar in the blood. The pancreas reacts by producing excess insulin initially, and after some time, gets fatigued and slows down production. As a result, blood-sugar levels cannot be controlled in both the stages.

Also Read: Type-2 Diabetes and Intermittent Fasting: Pros and Cons

Pancreatitis: Pancreatitis is a condition in which the pancreas get inflamed due to a blockage in the pancreatic-duct caused by a gall-stone or tumor. As a result, pancreatic juice starts accumulating in the pancreas and then digesting the tissues in it. Mumps, alcohol abuse and the use of steroids also increase the risk, while the condition itself is a risk for secondary diabetes. Again there are 3 types of this condition, each with their own set of symptoms.

Acute pancreatitis: is rarer and needs emergency treatment
Chronic pancreatitis: is more common, slowly developing and causes permanent damage
Hereditary pancreatitis: A family history of pancreatic conditions can cause a person in his/her mid-20s to develop either acute or chronic pancreatitis.

Pancreatic cancer: In the US, pancreatic cancer is the fourth-most common cancer in men, and fifth in women. Some of the risk factors are smoking and alcohol abuse. Before the cancer develops, there are some precursory signs such as lesions (Papillary Mucinous Neoplasms (IPMNs) and Pancreatic Intraepithelial Neoplasia (PanIN)).

Pancreatic cancer is again of 2 types – exocrine tumour called pancreatic adenocarcinoma that affects the pancreatic duct, and endocrine tumour that affects the islet of Langerhans. Symptoms include abdominal pain, jaundice, nausea, vomiting, loss of appetite, weakness, weight loss and fatty stools. Radiation, chemotherapy and surgery are the treatment options. In many cases, the pancreas is surgically removed. This is not a problem, and one can live without the pancreas, and take insulin injections and enzyme replacement pills for rest of the life.

Exocrine pancreatic insufficiency (EPI): The glandular tissue in the pancreas does not produce enough enzymes

Pancreatic cysts: Mostly associated with polycystic kidney disease or von Hippel-Lindau disease

Pancreatic fluid collections: Resulting from sudden and long-term inflammation of the pancreas

Zollinger-Ellison syndrome: In this, a tumor called as gastrinoma develops in the pancreas or the junction with duodenum

Outlook

There are several foods that irritate the pancreas, as well as several lifestyle habits that pose a risk for the above conditions. If you want to maintain good pancreatic health, consult an endocrinologist at a reputed hospital. He/she will advise you on the same.

It is also important to get an annual, comprehensive health checkup as some of the indications of the above conditions show up in these reports. An endocrinologist will then conduct more tests to confirm or rule out any pancreatic condition. And if confirmed, he/she will put you on a course of treatment for quick recovery and rehabilitation.

Reviewed by Dr Suresh S Venkita, Group Medical Director, Kauvery Hospitals

Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai, Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.

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