This document discusses the properties of receptors, including: 1. Differential sensitivity (specificity), where each receptor is specifically tuned to a single type of adequate stimulus and sensation, regardless of stimulation method. 2. Excitability (receptor potential), where the strength of the stimulus determines the magnitude of the receptor and action potentials generated. 3. Adaptation, where prolonged stimulation of a receptor results in a decline in response due to changes in receptor sensitivity over time.