Endocrine gland

An endocrine gland secretes a hormone (which is a signalling molecule) into the bloodstream where is travels to distant target cells where a cell response will take place. An example of an endocrine gland is the pancreatic islets where insulin is secreted into the bloodstream from the beta cells.

Endocrine glands are a key part of the endocrine system (the system of the body which synthesises then secretes hormones). They secretes hormones directly into the blood where hormones can affect the target cells via a specific cell surface receptor.