Answer:
The pancreatic islets of Langerhans are small clusters of endocrine cells scattered throughout the pancreas. They are responsible for producing and secreting hormones that regulate glucose homeostasis in the body.
There are four main types of cells that make up the pancreatic islets of Langerhans:
Alpha cells: These cells are responsible for producing and secreting the hormone glucagon. Glucagon acts on liver cells to promote the breakdown of glycogen into glucose, which can then be released into the bloodstream to raise blood glucose levels.
Beta cells: These cells are responsible for producing and secreting the hormone insulin. Insulin acts on muscle, fat, and liver cells to promote the uptake and storage of glucose, which helps lower blood glucose levels.
Delta cells: These cells are responsible for producing and secreting the hormone somatostatin. Somatostatin acts on both alpha and beta cells to regulate the secretion of glucagon and insulin, respectively.
PP cells: These cells are responsible for producing and secreting pancreatic polypeptide. The function of pancreatic polypeptide is not fully understood, but it is thought to play a role in regulating appetite and food intake.
Together, these four types of cells work together to regulate glucose homeostasis in the body. Insulin and glucagon act in opposition to each other to maintain stable blood glucose levels, while somatostatin and pancreatic polypeptide help regulate the secretion of these hormones. Dysfunction of the pancreatic islets of Langerhans can lead to various metabolic disorders, such as diabetes mellitus