Final answer:
The term 'It' refers to sensation, a process initiated by stimulation of sensory receptors leading to perception of the five senses: hearing, sight, taste, touch, and smell.
Step-by-step explanation:
The term 'It' in the provided statement refers to the complex process that begins when sensory receptors are activated by a stimulus. These receptors -- specialized neurons that respond to environmental stimuli such as light, sound, touch, and taste -- translate physical energy from these stimuli into electrical signals through a process called transduction. These signals are then relayed to the central nervous system where the brain interprets them, allowing us to experience the five senses: hearing, sight, taste, touch, and smell. These senses are crucial for interaction with the world around us, and each has its own specialized organs and receptors, like photoreceptors for vision and mechanoreceptors for hearing and balance. Somatosensation refers to our sense of touch, which includes pressure, vibration, and temperature, and unlike the other senses, its receptors are distributed throughout the body in various organs, including skin and muscle.