A reflex action involves:

A reflex action is an automatic, involuntary, and rapid response to a stimulus, designed to protect the body from harm. The neural pathway involved is called the **reflex arc**. ### The Reflex Arc Sequence: 1. **Stimulus**: A change in the environment (e.g., touching a hot surface). 2. **Sensory Neuron**: Transmits the impulse toward the Central Nervous System (CNS). 3. **Spinal Cord**: Instead of traveling to the conscious areas of the brain, the impulse reaches an interneuron in the spinal cord. 4. **Motor Neuron**: Transmits the impulse from the spinal cord directly to the effector. 5. **Effector**: A muscle or gland responds (e.g., pulling the hand away). Because the signal is processed in the **spinal cord** rather than the conscious brain, the reaction occurs significantly faster than a voluntary action. Therefore, a reflex action involves the **spinal cord, bypassing the brain**.