Signaling Site

Nearby cells are targeted (e.g., neurotransmitters).

Long-distance signaling via the bloodstream (e.g., hormones). signaling

Signaling between cells in physical contact. Nearby cells are targeted (e

The signal finally triggers a specific cellular activity, such as gene expression or enzyme activation. Types of Signaling: Autocrine: A cell targets itself. Nearby cells are targeted (e.g.