Is insulin secreted by the islets of Langerhans?

Insulin is secreted by the β-cells of the islets of Langerhans.

Insulin is a peptide hormone produced by pancreatic β-cells, which are widely distributed throughout the pancreatic tissue. Insulin is the body's primary anabolic hormone, mainly functioning to convert glucose from the blood into glycogen in the liver, muscle, and other cells. When a person eats or consumes high-sugar foods, blood glucose levels rise, prompting the β-cells in the pancreas to respond by secreting more insulin. Insulin then binds to receptors on cells and signals them to absorb glucose from the bloodstream. The absorbed glucose is converted into glycogen through glycogenesis and stored in various body tissues such as the liver, muscles, and fat cells. Glucagon and insulin are both peptide hormones secreted by the pancreas and play a crucial role in maintaining stable blood glucose levels.

When insulin is insufficient or its function impaired in the body, diabetes may develop. Type 1 diabetes results from inadequate insulin production in the body. Type 2 diabetes is caused by insulin resistance.