An endocrine cell carries out both the receptor and control center functions. Hormones and other chemical signals bind to target cell receptors, initiating pathways that culminate in specific cell responses.

Signaling by hormones involves three key events: reception, signal transduction and response. Reception of the signal occurs when the signal molecule binds to a specific receptor protein in or on the target cell. Each signal molecule has a specific shape that can be recognized by that signal's receptors. Receptors may be located in the plasma membrane of a target cell or inside the cell. The binding of a signal molecule to a receptor protein triggers events within the target cell signal transduction that result in a response, a change in the cell's behavior.

Cells that lack receptors for a particular chemical signal are unresponsive to that signal. The receptors for most water–soluble hormones are embedded in the plasma membrane, projecting outward from the cell surface. Binding of a hormone to its receptor initiates a signal transduction pathway, a series of changes in cellular proteins that converts an extracellular chemical signal to a specific intracellular response.

Depending on the hormone and target cell, the response may be the activation of an enzyme, a change in the uptake or secretion of specific molecules or rearrangement of the cytoskeleton. Signal transduction from some cell–surface receptors activates proteins in the cytoplasm that then move into the nucleus and directly or indirectly regulate transcription of specific genes.