Communication between animal cells may be through direct contact between cell molecul

Communication between animal cells may be through direct contact between cell molecules between surface-bound cells. This process is known as cell-cell recognition. There is another type of local signaling known as synaptic signaling which occurs in the animal nervous system. In this, an electric signal along a nerve cell triggers the secretion of neurotransmitter molecules. They diffuse across the synaptic gap to the target cell and the process continues. Both animals and plants use hormones for long-distance communication, in animals, it is known as endocrine signaling while in plants it is known as growth regulators. In animals, hormone molecules travel to target cells via vessels of the circulatory system, into which they are secreted by specialized cells. Plant hormones often reach their targets by moving through cells or diffusion through the air as gas but sometimes also travel in the vessel. Another example of long-term signaling is the transmission of the signal through the nervous system (Recce, 2005). After the signal is recognized by the receptor molecule, it is renewed into another form so the cell can respond to it.