Question

What will happen if Islets of Langerhans fail to function?

Answer 1

Islets of Langerhans are endocrine tissues located in the pancreas of most vertebrates. They got their name after the German physician Paul Langerhans, who first discovered them in 1869. About one million islets are present in normal human pancreas. The islets of Langerhans consist of four cell types namely alpha, beta, delta and gamma cells. The main function of islets of Langerhans is to produce insulin hormone.

Complete explanation:
The beta cell is the most common islet cell and it produces insulin. Insulin is the major hormone involved in the regulation of carbohydrate, fat and protein metabolism. Insulin promotes the uptake and metabolism of glucose by the cells of the body.
When the glucose level in the blood increases (after a meal), insulin is released by the islets to counter it. If the islet cells do not produce insulin or fail to produce in a sufficient quantity, the blood glucose level would increase and lead to a disease called diabetes mellitus.
The alpha cells of the islets of Langerhans produce a hormone called glucagon. Glucagon acts as an opposing hormone that releases glucose from the liver and fatty acids from fat tissue. Glucose and free fatty acids induce the release of insulin and inhibit glucagon release. If glucagon is not released by alpha cells, production and release of insulin will also be affected.

Note:
The delta cells of the islets produce a hormone called somatostatin. This hormone acts as a strong inhibitor of insulin, somatotropin and glucagon.The role of somatostatin in metabolic regulation is not yet clear. This hormone is also produced by the hypothalamus where it functions as an inhibitor of growth hormone secretion by the pituitary gland. The gamma cells produce pancreatic polypeptide that regulate the pancreatic secretion activities.