A reflex arc is a neural pathway that controls a reflex action. It typically involves a sensory neuron that detects a stimulus, such as touching something hot, and sends a signal to the spinal cord. This signal is then relayed to a motor neuron, which triggers a quick response, like pulling your hand away, without involving the brain for immediate reaction. The reflex arc consists of several key components: a sensory receptor, sensory neuron, interneuron (in some cases), motor neuron, and an effector, such as a muscle. This process allows for rapid responses to stimuli, helping to protect the body from harm and maintain homeostasis.