Final answer:
Hair cells in the cochlea serve as receptors/sensors, converting mechanical waves into electrical signals for the auditory system through sensory transduction.
Step-by-step explanation:
Hair cells in the cochlea of the ear are examples of receptors/sensors in a reflex loop. These cells perform sensory transduction, which is the conversion of a sensory stimulus into electrical energy within the nervous system by changing the membrane potential. The stereocilia on the hair cells are crucial for detecting sound waves. When these stereocilia are bent by vibrations, they respond by opening gated ion channels, causing the hair cell membrane to depolarize and generate a signal that is transmitted to the cochlear nerve. This process allows for the transduction of mechanical waves into electrical signals, essential for the sense of hearing.