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functions of receptors


As we know A-delta group fibers are myelinated which allows them to conduct faster action potentials. Their function explains why their speed is necessary as they respond primarily to sharp pressure or heat.  When touching a hot pan or waving your finger over a flame, it would probably be detrimental to have a slower signaling system rather than a faster one. The slower C fiber group of unmyelinated axons responds to intense stimulation to: pressure, heat or cold, or noxious chemicals. This kind of pain is the long lasting pain we feel after damage has already been done, such as the long-lasting burn related to sunburn.  If you recall the last time you had a painful experience, such as a deep gash or cut, you may remember a sharp burst of pain followed by a throbbing sensation.  These two stages reflect the first set of signals from the A-delta group followed by the second onset of the C fiber group as shown by the figure to the left.

source: Purves et. al