The primary role of sensory neurons in the nervous system is to transmit sensory information from sensory receptors to the central nervous system (CNS). These neurons detect stimuli from the environment, such as light, sound, touch, and temperature, and relay that information to the brain and spinal cord for processing. Once the brain interprets the signals, it can respond appropriately, leading to perception and reactions. Sensory neurons are vital for enabling organisms to interact with their surroundings and maintain homeostasis through informed decision-making.