What sequence describes a reflex arc in the nervous system?

A reflex arc is a neural pathway that is responsible for carrying out a reflex action. The sequence begins with sensory neurons, which detect a stimulus and convert it into an electrical signal. These neurons then transmit the signal to the spinal cord, where they synapse with interneurons or directly with motor neurons. This synaptic connection allows for an immediate response by the motor neurons, which relay signals to the muscles or glands to produce a reaction, such as withdrawing a hand from a hot surface.

The accurate sequence for a reflex arc is sensory neurons leading to a synapse in the spinal cord and then connecting to motor neurons, thereby facilitating a quick response without involving the brain. This is essential for survival, as it allows for rapid reflex actions that can protect the body from harm.