The Anatomy of the Pancreas

An Organ That Aids Digestion and Controls Blood Sugar

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The pancreas is a gland located deep inside the abdomen, just behind the lower part of the stomach. It has two important functions: secreting enzymes that aid in digestion and releasing hormones, in particular insulin, to help regulate the amount of glucose (sugar) in the blood).

Pancreas
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Anatomy

The pancreas is an elongated gland located deep within the abdomen, tucked in between the stomach and the spine. One end of the pancreas is wider than the other and is called the head: It sits within the curve of the duodenum (the first part of the small intestine) and is divided into two parts: the head proper and the uncinate process.

The uncinate process wraps around two important blood vessels, the superior mesenteric artery and the superior mesenteric vein.

Much like a comma lying on its side, the pancreas extends slightly upward, becoming narrower and narrower. It is divided into areas referred to as the neck, the body, and, finally, the tail, which is located near the spleen.

The pancreas is roughly the length of the hand—about six inches long.

Two types of gland comprise the pancreas, each with very different but vital functions. The exocrine gland, which runs the entire length of the pancreas, secretes digestive enzymes.

The endocrine portion of the pancreas is made up of groups of cells call the islets of Langerhans. There are three types of cells in the islets, each of which secretes different hormones that help to regulate the amount of sugar in the bloodstream.

The pancreas.

Function

The pancreas plays key roles in two important functions in the body—digestion and blood sugar control. These functions are performed independently.

Digestion

Each of the digestive enzymes secreted by the pancreas work in different ways to break down food, traveling to the duodenum via ducts:

  • Lipase. Works with bile (produced by the liver) to break down fat—important for absorbing fat soluble vitamins.
  • Protease. Breaks down proteins and provides protection from bacteria, yeast, and other potentially harmful microbes that live in the intestines.
  • Amylase. Breaks down starches into sugar to be used for energy.

The pancreas produces approximately 8 ounces of enzyme-filled digestive juices each day.

Blood Sugar Control

Specific cells in the islets of Langerhans secret three different hormones responsible for controlling the levels of sugar in the blood.

  • Insulin: The cells responsible for releasing this hormone are called beta cells; they make up 75% of pancreatic cells.
  • Glucagon: The pancreas releases this hormone when there is too little sugar in the blood to signal the liver to release stored sugar. It is secreted by alpha cells, which make up 20% of cells in the pancreas.
  • Gastrin: Gastrin prompts the stomach to produce gastric acid; most gastrin is made in the stomach but the pancreas manufactures a small portion.
  • Amylin: Also produced by the beta cells, this hormone is involved in appetite control and emptying of the stomach.

Associated Conditions

The illness most often connected to the pancreas is type 1 diabetes, an autoimmune disease in which the immune system mistakenly attacks and destroys beta cells in the gland. As a result, little to no insulin is produced and the levels of glucose in the blood can fluctuate. Type 1 diabetes is a life-long disease that cannot be cured; it is primarily managed with daily injections of supplemental insulin.

In type 2 diabetes, the pancreas is not attacked by the immune system, but it either produces less insulin than is needed or the body is unable to use the insulin it does produce. The latter condition is called insulin resistance. Obesity is a major cause of insulin resistance.

Other conditions involving the pancreas are pancreatitis, pancreatic cancer, and cystic fibrosis. The pancreas is also linked to non-diabetic hypoglycemia and hyperglycemia.

Restoring pancreatic function essentially would be a cure for type 1 diabetes and there are several potential methods of doing so. All are regarded as experimental.

  • Regenerating beta cell function so that they again will produce insulin
  • Islet cell transplantation, a somewhat successful but risky procedure
  • Pancreas transplant. Donors are limited, and so this procedure usually is reserved for people who are seriously ill due to type 1 diabetes complications.

Tests

Type 1 diabetes is diagnosed with blood tests that measure the amount of glucose in the blood. Blood glucose is sometimes used in the diagnosis of pancreatic cancer.

Diagnosing other diseases and conditions involving the pancreas is done with any of a variety of lab and imaging tests.

  • CA19-9 blood test: The presence a protein called CA19-9 is an indication of cancer. (CA stands for "cancer antigen.") It is most often measured to evaluate how well pancreatic cancer is responding to treatment but can be used in diagnosis.
  • Secretin pancreatic function test: Measures how well the pancreas is able to respond to a hormone called secretin. It involves the insertion of a thin tube through the nose to the duodenum (the first part of the small intestine) followed by secretin given intravenously (into the body through a vein). The tube is used to remove fluids released over an hour or two for evaluation.
  • Fecal elastase test: Measures the amount of elastase in the stool. Elastase is a digestive enzyme that's present in fluids produced by the pancreas. This test is used to diagnose exocrine pancreatic insufficiency (EPI), a condition characterized by chronic diarrhea.
  • Computed tomography (CT) scan with contrast dye: An imaging test that can detect problems in and around the pancreas, such as swelling or scarring. It also can help to rule out problems with the pancreas as a cause of abdominal pain.
  • Abdominal ultrasound: An imaging test that uses sound waves to create images of organs in the abdominal area.
  • Endoscopic retrograde cholangiopancreatography (ERCP): An imaging test that combines endoscopy and X-rays to evaluate the pancreas and the bile ducts. It involves feeding a thin tube through the throat to the intestines and injecting contrast dye to make the pancreatic duct and nearby structures visible.
  • Endoscopic ultrasound: Useful for diagnosing severe pancreatitis
  • Magnetic resonance cholangiopancreatography: An MRI test focused on the pancreas and bile ducts.
  • Angiography: A special X-ray using contrast dye to observe if blood flow is being obstructed by a tumor.
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4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Johns Hopkins Medicine. The Sol Goldman Pancreatic Cancer Research Center. Parts of Pancreas.

  2. Johns Hopkins Medical. The Digestive Process: What is the Role of Your Pancreas in Digestion?

  3. Cleveland Clinic. Pancreas Function Tests. Oct 27, 2017.

  4. American Cancer Society. Tests for Pancreatic Cancer. Jan 2, 2020.

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