The receptor response decline despite of the continued presence of a stimulus is know as:
Adaptation: When a maintained stimulus of constant strength is applied to a receptor the frequency of the action potentials in its sensory nerve declines over time. This phenomenon is known as adaptation or desensitization. Ref: Ganong's Review of Medical Physiology, 21st Edition, Page 125
Accomodation
Adaptation
Refractoriness
Electrotonus