Cell signalling

Cell Signalling is the transfer of information, that controls the cell behaviour, whether from cell to cell, or from environment to cell.
There are many different types of cell signalling that vary immensley. About 10-15% of the genome codes for the creation of these cell signalling molecules.

The shortest signalling pathway is between adjacent cells - called a gap junction. The pathway size then increase from gap junction, to contact dependant, where there is the signal displayed on the surface and a receptor on another cell surface, for example, an immune response cell. Paracine pathway secretes a signal into the interstitial fluid within the same tissue. The next longer pathway is Autocrine signalling and Synaptic signalling. The longest signalling pathway, which usually has the longest response time to stimulus/impulse is Endocrine signalling, where the signal is secreted into the blood stream which flows around the body.

There are 5 stages; Signal, Reception, Transduction, Amplification and Response