The pancreas is an abdominal organ made of glandular tissue and a system of ducts. It is located between the stomach and the spine. The pancreas has two major functions:
To produce enzymes that aid in the digestion of carbohydrates, fats and proteins. These enzymes, which regulate metabolism, are released into ducts by exocrine cells (the term exocrine means to release externally, into ducts).
To produce hormones essential to regulating the body's main energy source, called glucose (blood sugar), in the bloodstream. These hormones include insulin, which is necessary to lower glucose levels by moving it into cells, and glucagon, which raises glucose levels in the blood. They are produced by endocrine cells (endocrine means to release internally, into the bloodstream).
The pancreas also produces other hormones, such as gastrin (to regulate acid secretion) and somatostatin (to regulate insulin, glucagon and other hormones). These hormones are produced in clusters of cells spread throughout the pancreas. These clusters, called the islets of Langerhans, are composed of specialized cells known as alpha, beta and delta cells.
Damage to the beta cells can cause insulin production to slow or stop completely. Without insulin to move glucose into cells, the level of glucose in the blood will rise. This condition is known as diabetes. Other conditions that can affect pancreas function include:
Pancreatitis. Inflammation of the pancreas.
Pancreatic cysts. Sacs of fluid that are usually caused by pancreatitis.
Pancreatic cancer. A form of cancer that spreads quickly and is rarely found in its early stages.
Pancreatic insufficiency. Occurs when the pancreas fails to make enough enzymes for proper digestion.
About pancreas function
The pancreas is an elongated, flattened glandular organ with two vital responsibilities. It produces enzymes necessary to digest carbohydrates, fats and proteins, and it produces insulin, a hormone that is essential in the regulation of glucose (blood sugar), the body's main source of energy.
This oblong gland, which measures about 5 to 6 inches (13 to 15 centimeters) long, is located between the stomach and the spine. It is composed of glandular tissue and a system of ducts, which are tubes that carry the fluids secreted by glands. The main duct is known as the pancreatic duct. It transports fluid and enzymes from the gland to the duodenum, the upper part of the small intestine.
The pancreas is usually described either by the function of its cells or by its parts. It has two functional components:
Endocrine cells (also known as the islets of Langerhans, islet cells or beta-islet cells). “Endo” means within. There are about 100,000 endocrine cells scattered throughout the pancreas. The pancreatic hormones produced in the islets of Langerhans are composed of various types of cells, including alpha, beta and delta cells. These are responsible for producing and secreting hormones into the bloodstream, including insulin (produced by beta cells), which lowers glucose levels, and glucagon (produced by alpha cells), which raises glucose levels. These hormones maintain proper glucose levels within the bloodstream and help the body use that sugar for energy within the cells. Delta cells in endocrine tissue secrete somatostatin, a hormone that inhibits the release of insulin and glucagon. The pancreas also produces gastrin, a hormone that stimulates the stomach to produce digestive acid.
Exocrine cells (also known as acinar cells or non-endocrine cells). “Exo” means outward. These cells make up the majority of the pancreas. They produce and transport proteins (known as enzymes) and fluids that assist in digestion of carbohydrates, fats, proteins and acids in the duodenum. The enzymes are secreted into ducts joined to the main pancreatic duct that is found along the length of the pancreas. The enzymes then travel down into the area where the pancreatic duct enters the duodenum together with the bile duct within a bulbous structure known as the ampulla of Vater. Finally, the enzymes enter the duodenum and become activated. Exocrine tissue also secretes bicarbonate that neutralizes stomach acid and inhibits the formation of ulcers.
The pancreas can also be categorized by its five sections:
Head. The gland’s widest part, it is on the right side of the abdomen and lies in the curve of the duodenum.
Neck. A thin section located between the gland’s head and body.
Body. The middle part of the pancreas, it is found between the neck and tail. The body is located in front of the superior mesenteric blood arteries and veins, which supply the intestines with blood.
Tail. The thin tip, it is found on the left side of the abdomen near the spleen.
Uncinate process. This part bends backward and is found underneath the pancreas’ head. The superior mesenteric arteries and veins cross in front of this part.
When food is digested, it is transported through the esophagus and into the stomach. There, digestive juices break down (digest) food. The food then flows into the duodenum where digestion continues.
At this point, bile, a greenish-yellow liquid produced in the liver that assists in digesting fats and pancreatic fluids is secreted into the small intestine. These liquids, along with the food, continue through the small intestine, where glucose travels into the bloodstream, and then through the large intestine and rectum.
The glucose traveling through the bloodstream is allowed to enter body cells because of insulin. Without enough insulin, the body is unable to use glucose for energy. High levels of glucose circulating in the blood for a long period of time (years) can damage nerves, blood vessels and other body systems.
Pancreatic conditions
There are a variety of diseases and conditions that may affect the pancreas. The pancreas is located deep in the body against the spine, and this can hamper a physician’s efforts to diagnose diseases of the pancreas. Disorders of the pancreas include:
Diabetes. A condition resulting from a deficiency of insulin, a hormone that is essential in the regulation of glucose (blood sugar) in the body. Normally, the beta cells in the pancreas continually produce a steady amount of insulin (known as baseline, basal or background insulin) that is just enough to move glucose into cells. Insulin production automatically increases when the body senses higher levels of glucose circulating in the blood, such as just after a meal. However, damage to the beta cells can interfere with insulin production. Without insulin, glucose levels can rise to harmful levels and lead to diabetes.
Pancreatitis. Inflammation of the pancreas that can be either acute or chronic. It occurs when digestive enzymes activate while still inside the pancreas and start digesting the pancreas itself. In some cases, pancreatitis may be caused if a gallstone blocks a pancreatic duct. Alcohol overuse can cause acute and chronic pancreatitis.
Pancreatic cancer. A serious form of cancer because it spreads quickly and is rarely found in its early stages. Symptoms include jaundice (yellowing of the skin and the whites of the eyes), abdominal pain and unexplained weight loss. Treatment is surgical removal of the tumors, if they are detected early enough.
Cystic fibrosis (CF). A genetic disorder in which the body produces thick mucus that interferes with respiratory function and the exocrine system of the pancreas (involving digestive substances and enzymes). Because this mucus blocks the pancreatic ducts, it prevents digestive enzymes from reaching the small intestine, which leads to malnutrition and insufficient digestion.
Pancreatic insufficiency. A condition in which the pancreas fails to make enough enzymes for proper digestion. It is not a disease itself, but a sign of another problem. Chronic pancreatitis is the most common cause of pancreatic insufficiency in adults. It can result in malabsorption (ineffective nutrient absorption by the intestines), unexplained weight loss and diarrhea.
Pancreatic cysts. Sacs of fluid that form in the pancreas and are usually caused by pancreatitis.
Shwachman-Diamond Syndrome. A rare condition characterized by improper functioning of the cells of the pancreas. This condition, which affects people of all ages, is the second most common cause of pancreatic insufficiency in children. It is sometimes mistaken for CF, the leading cause of pancreatic insufficiency in this population.
Zollinger-Ellison syndrome. A rare condition in which tumors (including gastrinomas) form in the pancreas or the duodenum. Gastrinomas secrete the hormone gastrin in large amounts, causing excess acid production and peptic ulcers.
Questions for your doctor on pancreas function
Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to pancreas function:
What is the purpose of my pancreas?
Where is my pancreas located?
Could a pancreatic disorder be the source of my symptoms?
Why do you suspect that my pancreas may be damaged?
How can you tell if my pancreas is damaged?
How might damage to my pancreas affect my health?
What factors could have contributed to my pancreatic damage?
Which diseases might affect my pancreas’ ability to function?
If my pancreas is unable to produce insulin, will this increase my chances of diabetes?
How might damage to my pancreas affect my ability to digest food?
