Having the capability of being excitable.
- supranormal e. at the end of phase three of the cardiac action potential, the successful stimulation threshold falls below ( i.e., less negative than) the level necessary to produce excitation during the rest of the phase of diastole, so that an ordinary subthreshold stimulus becomes effective. Cf.:supranormal conduction.
* * *
ex·ci·ta·bil·i·ty (ek-sīt″ə-bilґĭ-te) 1. irritability. 2. the capacity of a cell to depolarize and form an action potential when in the presence of a stimulus stronger than a threshold value.Medical dictionary. 2011.