second messengers

Second messengers are molecules that relay signals inside cells after an initial signal, like a hormone or neurotransmitter, binds to a receptor on the cell's surface. They amplify and propagate the signal, triggering various cellular responses. Common second messengers include cyclic AMP (cAMP) and calcium ions. Think of them as internal communication devices that help cells respond to external cues, enabling functions like metabolism, growth, and memory. Their role is crucial in maintaining cellular functions and ensuring that cells react appropriately to changes in their environment.