Final answer:
The sensory neurons transmit information to interneurons in the spinal cord during a reflex arc, enabling a rapid, protective response.
Step-by-step explanation:
The simple pathway of a reflex arc starts with sensory neurons picking up information through the skin and relaying it to interneurons in the spinal cord.
In a reflex arc, sensory neurons in the skin detect a stimulus such as heat, pressure, or pain and send a signal through their axons to the spinal cord. Here, the signal is transmitted to interneurons, which process the information and quickly relay it to motor neurons. These motor neurons then send an impulse to a muscle, leading to an immediate response, such as pulling your hand away from a hot surface. This pathway enables a rapid reaction to stimuli, bypassing the brain, which is essential for protective reflexes.