Which gland secretes insulin?

The pancreas is the gland responsible for the secretion of insulin, which plays a crucial role in regulating blood glucose levels. It contains clusters of cells known as islets of Langerhans, within which beta cells are specifically involved in producing and releasing insulin in response to elevated blood glucose levels. When food intake raises blood sugar, insulin facilitates the uptake of glucose into the cells for energy or storage, helping to maintain homeostasis within the body.

Understanding the function of the other glands is important. The thyroid gland primarily produces hormones that regulate metabolism, while the adrenal gland is involved in producing hormones related to stress response and metabolism, such as cortisol and adrenaline. The parathyroid gland regulates calcium levels in the blood through parathyroid hormone but does not play a role in glucose metabolism or insulin secretion. This understanding highlights the unique and vital function of the pancreas in endocrine regulation.