Pancreas Health Article

Definition

The pancreas is an organ important in digestion and blood sugar regulation. It is considered to be part of the gastrointestinal system. The pancreas produces digestive enzymes to be released into the small intestine to aid in reducing food particles to basic elements that can be absorbed by the intestine and used by the body. It has another very different function in that it forms insulin, glucagon and other hormones to be sent into the bloodstream to regulate blood sugar levels and other activities throughout the body.

Description

The pancreas is a pear-shaped organ about 6 in (15 cm) long located in the middle and back portion of the abdomen. It is connected to the first part of the small intestine, the duodenum, and lies behind the stomach. The pancreas is made up of glandular tissue, or cells that form substances to be secreted outside of the organ. Glandular tissues can be categorized as endocrine (secreting directly into the bloodstream or lymph) or exocrine (secreting into another organ). The pancreas is both an exocrine and an endocrine organ.

Exocrine secretions

The digestive juices produced by the pancreas are secreted into the duodenum via a Y-shaped duct, at the point where the common bile duct from the liver and the pancreatic duct join just before entering the duodenum. In this way, a variety of digestive enzymes (trypsin, chymotrypsin, lipase, and amylase, among others) are delivered into the small intestine to aid in the digestion of proteins, fats, and carbohydrates. The enzymes are delivered in an inactive form called zymogens. The zymogens are activated by the chemical substances in the small intestine. The digestive enzymes carried into the duodenum are representative of the exocrine function of the pancreas, in which specific substances are made to be passed directly into another organ.

Endocrine secretions

The pancreas is unusual among the body's glands in that it also has a very important endocrine function. Small groups of special cells called islet cells throughout the organ make such hormones as insulin and glucagon, which are critical in regulating blood sugar levels; and vasoactive intestinal peptide, which influences gastrointestinal activity. These hormones are secreted directly into the bloodstream to affect organs all over the body. No organ except the pancreas makes significant amounts of insulin or glucagon, but other tissues do produce vasoactive intestinal peptide. Insulin acts to lower blood sugar levels by allowing the sugar to flow into cells. Glucagon acts to raise blood sugar levels by causing glucose to be released into the circulation from its storage sites. Insulin and glucagon act in an opposite but balanced fashion to keep blood sugar levels stable.

Role in human health

A normal pancreas is important for maintaining good health, preventing malnutrition, and maintaining normal levels of blood sugar. The digestive tract needs the help of the enzymes produced by the pancreas to reduce food particles to their simplest elements, or the nutrients cannot be absorbed. Carbohydrates must be broken down into individual sugar molecules. Proteins must be reduced to simple amino acids. Fats must be broken down into fatty acids. The pancreatic enzymes are important in all these transformations. The basic particles can then easily be transported into the cells that line the intestine, and from there they can be further altered and transported to different tissues in the body as fuel sources and construction materials.

Similarly, the body cannot maintain normal blood sugar levels without the balanced action of insulin and glucagon. Both hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar) cause symptoms and serious health problems.

Diabetes

Glucose is a simple sugar molecule, but one that is necessary to every type of cell as a major source of energy. Insulin made in the pancreas has a critical role in permitting glucose to enter cells. Without insulin, the cells of the body literally "starve in the midst of plenty," and are unable to make use of sugar in the blood even if blood sugar levels are very high. This condition is called diabetes mellitus. Diabetes actually represents a collection of disorders resulting in high blood sugars related to abnormal insulin levels, or abnormalities of the receptor that binds the insulin to allow glucose to enter the cell. Diabetes is quite common in the United States, affecting 1–2% of the general population.

Type I diabetes, which is sometimes called insulin-dependent diabetes, is a disease in which a patient must use insulin regularly to avoid serious problems with cells starving for glucose and acidic waste products accumulating in the blood. In this form of diabetes, the pancreas is essentially not producing insulin. Pancreas transplantation is a method of treating type I diabetes that has achieved success rates of 80–85% in the past decade, success being defined as the organ recipient's remaining insulin-independent. In type II diabetes, or non-insulin-dependent diabetes, blood sugar levels can often be controlled with diet, exercise, and medications taken by mouth. In some forms of type II diabetes the pancreas is not producing enough insulin; in other cases the receptor that binds insulin is no longer sensitive to it, or too few receptors are made by the cells that need glucose. Sometimes a combination of these problems is present. Gestational diabetes mellitus (GDM) is a third type of diabetes, which is a temporary problem with blood sugar levels that exists only during pregnancy. Women with GDM, however, need to know they are at increased risk for developing type II diabetes.