During ventricular systole the cardiac muscle does not respond to additional stimulation because it is in the phase of:

Answer options

1. Hyperexcitability
2. There is no correct answer
3. Absolute refractoriness
4. Subnormal excitability
5. Relational refractoriness

Explanation

In the absolute refractory period, Excitability is depressed and as a result, action potentials of threshold intensity cannot stimulate the heart any further.