Molecular nature of cell signals

Cells usually communicate with each other by sending signals. These signals are not like any signal we are used to send. They are not electromagnetic or they don’t flow through a cable. Signals are in the form of molecules and the process they are transmitted is diffusion. These molecules reach their target through diffusion. The process of diffusion requires a continuous liquid medium from source to target.

Diffusion is a passive process, molecules don’t know where they are going- actually they go to every possible direction. In this aspect they are like electromagnetic wave and become weaker (less concentrated) as distance increases.