Islets of Hope      What is the pancreas?

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Article by Lahle Wolfe, Founder, Islets of Hope.

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Medical definitions of words helpful in understanding this article

acinar cells - (also called acinous cell) - cells that comprise small sacs terminating the ducts of some exocrine glands. In the pancreas, acinar cells furnish pancreatic juice.

alpha cells - endocrine cells in the islets of Langerhans of the pancreas that produce the hormone glucagon.

beta cells - endocrine cells found in the islets of Langerhans of the pancreas that secrete the hormone insulin.

carbohydrate metabolism - the digestive process of how the body breaks down ingested (eaten) carbohydrates (starches and sugars) from food into a useable form of energy called glucose.  

Glucose is then released into the bloodstream to be used by cells in the body.  In diabetes, this stage of carbohydrate metabolism is impaired.

The liver can also metabolize carbohy- drates by breaking down glycogen into glucose and releasing it into the bloodstream.

delta cells - found in the islets of Langerhans in the pancreas that produce the hormone somatostatin, an inhibitor of the pituitary hormone somatotropin

duodenum - the first,or beginning portion of the small intestine, starting at the lower end of the stomach and extending to the jejunum.

endocrine - endo (within) + crine (secrete) - of or relating to endocrine glands or the hormones secreted by them.

The endocrine hormones insulin and glucagon are secreted into the bloodstream.

enzyme - a secretion by the exocrine system that acts as a catalyst, causing a temporary, accelerated change in reactions. Enzymes help other chemicals react together or other substances to change. Example: stomach enzymes help break down and digest food.

exocrine - exo (outward) + crine (secrete) - of or relating to a glandular secretion that is released externally through a duct to a surface.

The pancreas produces exocrine enzymes that are secreted into the beginning part of the intestine (duodenum) to help with digestion of food.

gastric - related to the stomach.

gastrin - a hormone released after eating, which causes the stomach to produce more acid.

gland - an organ that manufactures chemical substances. A gland may vary from a single cell to a complex system of tubes that unite and open onto a surface through a duct. Some glands have dual functions, e.g., the liver, pancreas, ovary, and testis produce both a secretion that is emitted through a duct and a hormone that is taken up by the blood. Such structures are called mixed glands.

glucagon - a polypeptide hormone produced in the pancreas by the alpha cells of the islets of Langerhans.  Glucagon opposes the action of insulin (which lowers blood sugar levels) by stimulating the release of stored glycogen in the liver.  This release causes an increase in blood sugar.

Glucagon also raises blood sugar levels by preventing the liver from storing glucose and increasing glucose formation in the liver from dietary proteins and fats.

All persons who take insulin should carry injectable glucagon with them at all times.  In the event of insulin shock, injected glucagon is necessary.

hormone - chemical substance produced by certain endocrine glands (the pancreas is one) that is released into the bloodstream where it controls and regulates functioning of other tissues.

idiopathic - of unknown cause or of spontaneous origin.

insulin - a hormone secreted by the pancreas that regulates the levels of sugar in the blood. hormone secreted by the isles of Langerhans in the pancreas; regulates storage of glycogen in the liver and accelerates oxidation of sugar in cells

islets of Langerhans (also called islands of Langerhans) - clusters of hormone producing cells distributed throughout the endocrine tissue of the pancreas.

Alpha cells secrete the glucagon, beta cells secrete insulin, and Delta cells secrete somato- statin.

renin - a hormone produced and released by the kidneys that helps regulate blood pressure.

secretin - hormone made in the duodenum. Causes the stomach to make pepsin, the liver to make bile, and the pancreas to make a digestive juice.

somatostatin - hormone in the pancreas that helps tell the body when to make the hormones insulin, glucagon, gastrin, secretin, and renin.

think like a pancreas  
Gary Scheiner, CDE
Think Like a Pancreas

Many books offer advice on managing diabetes, but few focus specifically on the day-to-day issues facing those who use insulin.

Scheiner, a certified diabetes educator and himself an insulin user himself since 1985, gives you the tools to "think like a pancreas"--that is, to successfully master the art and science of matching insulin to the body’s ever-changing needs.

Think Like a Pancreas discusses: day-to-day blood glucose control and monitoring,designing an insulin program,measuring insulin to carbohydrate intake and physical activity, pluses and minuses of different insulin-delivery methods, optimal management of diabetes using an insulin  pump, hypoglycemia—the best ways to avoid it and treat it, the impact of emotions, stress, illness, and aging , making the best use of your health care team and community resources , plus dozens of other issues that everyone taking insulin needs to understand and master.     IOH Rating 5/5 

Additional reading and images of the pancreas

Illustrated Pancreas

The National Pancreas Foundation

The UC Pancreatic Disease Center

Types of pancreatitis

Pancreatic Cancer


diabetes medical terms
Medical Encyclopedia                    Back to search index


pancreas             pronounced: pan-kre-us.  Greek - meaning "all flesh" or "all meat

Mini site index
What is the pancreas?
Tissues of the pancreas
Islets of Langerhans
Parts of the pancreas
How are diabetes and the pancreas connected?
Medical concerns with the pancreas


What is the pancreas?

The pancreas is a long, irregularly shaped gland that is found in vertebrates (organisms with a backbone). It is made of protein and is located behind the stomach.

Some describe the shape of the pancreas as a fishlike with a long tail and large head.  Others describe it as being shaped like the letter "J" with the top portion connecting to the duodenum (the beginning part of the small intestine).  

The human pancreas is yellowish in color and about 7 inches (17.8 cm) long and 1.5 inches (3.8 cm) wide. 

The pancreas secretes both hormones and enzymes.


Tissues of the pancreas

The pancreas is made up of two types of tissues; exocrine and endocrine.

Exocrine tissue of the pancreas
exo (outward) + crine (secrete)

The chemicals produced by the exocrine cells in the pancreas are called enzymes. These are proteins secreted into the duodenum (the beginning part of the small intestine) where they help with the digestion of food.

Pancreatic exocrine tissue is comprised of Acinar cells and the pancreatic ducts. These exocrine cells of the pancreas produce and transport enzymes that help with digestion and will eventually exit the body through the digestive tract.

The exocrine tissue of the pancreas secretes digestive enzymes, or pancreatic "juice," into the duodenum.  Small numbers of these exocrine cells in the tail of the pancreas, called PP cells, secrete pancreatic polypeptide, which slows down nutrient absorption. This enzyme is also responsible for coordinating exocrine and islet enzyme release.


Endocrine tissue of the pancreas
endo (within) + crine (secrete)

Pancreatic endocrine tissue consists of cell clusters known as islets of Langerhans.  These cells produce and secrete hormones into the bloodstream. Two of the main pancreatic hormones are insulin and glucagon. These hormones work together to maintain the proper level of sugar in the blood.  Insulin works to lower blood sugar and glucagon works to increase blood sugar.

When the insulin-secreting cells fail to function properly diabetes occurs.  The two major (but not all of the types of) diabetes are type 1 diabetes (juvenile diabetes) and type 2 diabetes (adult onset ). 

The endocrine tissue includes the islets of Langerhans.

picture islets of langerhans

Islets of Langerhans (also called islands or isles of Langerhans)

The endocrine tissue of the pancreas includes the islets of Langerhans.  This area is responsible for the production and release of certain hormones into the bloodstream.  The main three types of cells that produce hormones in the islets of Langerhans are:

  • Alpha cells - release the hormone glucagon, which triggers the release of glycogen form liver stores and helps to raise the level of glucose (sugar) in the bloodstream
  • Beta cells - release the hormone insulin, which help regulate carbohydrate metabolism into the bloodstream, and
  • Delta cells - release the hormone somatostatin into the bloodstream that acts as an inhibitor to the pituitary hormone called somatotropin and helps tell the body when to make other hormones like insulin, glucagon, gastrin, renin, and secretin.  

Parts of the pancreas

There are five main parts of the human pancreas:

  • Head - the right side of the pancreas is located in the curve of the duodenum and is called the head.  It is the widest part of the organ.
  • Neck - the thin part of the pancreas located between the head and body.
  • Tail -  the thin tip of the pancreas, located in the left part of the abdomen, and ends near the spleen.
  • Body - the tapered, left side of the pancreas.  The body is the middle portion of the gland, between the head and the tail.
  • Uncinate  - This is the part of the pancreas that bends backwards and underneath the body of the pancreas.  There are two very important blood vessels that cross in front of the ucinate process called the superior mesenteric artery and vein.

The pancreas also contains the following:

  • Stalk - Inside the pancreas is a long duct called the "stalk."  This duct runs down the center of the pancreas.
  • Grapes - The inside of the pancreas contains a stalk (see above) with clusters attached.  These clusters resemble a stalk of grapes.  The grapes are actually clusters of cells which flow into the stalk-like duct and then later into the duodenum. This system of stalk and grapes helps facilitate the digestion of protein, fats, and carbohydrates.
  • Islets of Langerhans - which includes Alpha, Beta, and Delta cells.


How are the pancreas and diabetes connected?

Diabetes mellitus occurs as a result of destruction of  the islet cells in the pancreas for many reasons including:

  • pancreatitis
  • tumors
  • drugs (steroids, thiazides, pentamidine)
  • hemochromatosis (can cause "bronze diabetes" due to hemosiderin deposition in pancreas)
  • hereditary ceruloplasmin deficiency (hereditary hemochromatosis, the most common form)
  • surgery
  • infections (congenital rubella, CMV, coxsackie virus [i.e. hand, foot and mouth disease])
  • endocrinopathies (disorders in the function of an endocrine gland and the consequences there of, i.e., pancreas, pituitary, adrenal, pregnancy which can cause gestational diabetes)
  • gestational diabetes
  • idiopathic (spontaneous, unknown cause or origin)

Medical concerns with the pancreas

Related information links

Pancreas transplantation
The pancreas
Pancreas transplant
Partial pancreas transplant
Types of pancreas transplant surgery

What's new in pancreas transplantion?

Research information links about diabetes and islet transplantation
What is islet transplantation?
About the pancreas
Islet cells and two important hormones they make

Research updates
Islet cell transplant centers


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  Richard R. Rubin, Ph.D., C.D.E.
Psyching Out Diabetes:  
This book examines the psychological obstacles of diagnosis such as panic, fear, anger, shame, and guilt and how to put them into perspective. Through proper maintenance, diet, and education, this book is tailor-made for the diabetic or anyone with a diabetic in their life who wants to overcome the negative emotions associated with this disease and learn the coping skills necessary to integrate diabetes into their daily life.  Dr. Rubin is a faculty member of the John's Hopkins Medical School.

Page Updated 07/25/2007