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

Answer options

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

Explanation

The refractory period is the recovery time of an excitable membrane to be ready for a second stimulus once it returns to its resting state. That’s why the muscles do not respond to additional stimulus in a normal state.