Excitation (Physiological)
In physiology, excitation means that certain systems have the ability to react automatically to stimuli in their environment.
Synapses, for example, convey the information that the fingertip feels something via the release of neurotransmitters to the continuing nerve cell. The docking of the neurotransmitters to the receptor of the postsynaptic membrane causes a change in the Permeabilität/en|permeability of the cell membrane.
This passes the information on to the brain, which makes us conscious of this sensation.