Pancreatic islets

Pancreatic islets also known as Islets of Langerhans are tiny clusters of cells scattered throughout the pancreas. They play a crucial role in the endocrine system, regulating blood glucose levels by producing and releasing hormones including insulin and glucagon.

Structure

The pancreatic islets are made up of several types of cells, each with a specific role. These include:

• Alpha cells (A cells) that produce glucagon
• Beta cells (B cells) that produce insulin and amylin
• Delta cells (D cells) that produce somatostatin
• PP cells or gamma cells that produce pancreatic polypeptide
• Epsilon cells that produce ghrelin

Function

The primary function of the pancreatic islets is to maintain normal blood glucose levels. This is achieved through the production and release of hormones that either increase or decrease glucose levels.

• Insulin, produced by beta cells, lowers blood glucose levels by promoting the uptake and storage of glucose in cells.
• Glucagon, produced by alpha cells, raises blood glucose levels by promoting the breakdown of glycogen into glucose in the liver.
• Somatostatin, produced by delta cells, regulates the endocrine system by inhibiting the release of other hormones including growth hormone and thyroid-stimulating hormone.
• Pancreatic polypeptide, produced by PP cells, regulates the secretion of pancreatic digestive enzymes.
• Ghrelin, produced by epsilon cells, stimulates hunger and increases food intake.

Clinical significance

Dysfunction or destruction of the pancreatic islets can lead to a number of diseases, most notably diabetes mellitus. In type 1 diabetes, the body's immune system attacks and destroys the beta cells, leading to a lack of insulin. In type 2 diabetes, the body's cells become resistant to the effects of insulin.

Other conditions associated with pancreatic islet dysfunction include hyperinsulinism, hypoglycemia, and pancreatic cancer.

See also

• Pancreas
• Endocrine system
• Diabetes mellitus
• Insulin
• Glucagon

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  Pancreatic islet tissue illustration
• Mouse pancreatic islet
  Mouse pancreatic islet
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  Pancreatic polypeptide
• Insulin immunohistochemistry
  Insulin immunohistochemistry
• Glucagon
  Glucagon
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  Pancreatic islets
• Islet structure
  Islet structure