Langerhans islets, also known as pancreatic islets, are distinct regions within the pancreas that play a crucial role in regulating blood glucose levels in the body. They are named after Paul Langerhans, the German physician who first discovered them in 1869.
Langerhans islets are small clusters of cells scattered throughout the pancreas, primarily located in the exocrine tissue surrounding the pancreatic ducts. These islets comprise only about 1-2% of the pancreas' total mass. They consist of several types of specialized cells, each with distinct functions.
The main cell types found in Langerhans islets are alpha cells, beta cells, delta cells, and gamma cells. Beta cells are the most common and are responsible for producing and releasing insulin, a hormone that helps regulate blood sugar levels by promoting the uptake and storage of glucose. Alpha cells produce glucagon, a hormone that increases blood glucose levels by stimulating the breakdown of stored glycogen in the liver. Delta cells produce somatostatin, a hormone that helps regulate insulin and glucagon release. Gamma cells, also known as PP cells, produce pancreatic polypeptide, which plays a role in various physiological processes.
Dysfunction of Langerhans islets can lead to various metabolic disorders, including diabetes mellitus. In type 1 diabetes, the immune system attacks and destroys the beta cells, causing a deficiency in insulin production. In type 2 diabetes, the body becomes resistant to the effects of insulin, leading to elevated blood glucose levels.
In summary, Langerhans islets are specialized regions within the pancreas that contain different types of cells responsible for regulating blood glucose levels, primarily through the production and release of hormones such as insulin and glucagon.
