The word for an organ or tissue that brings about the response in a reflex action is the effector. Effectors are typically muscles or glands that carry out the response generated by the reflex arc after receiving signals from efferent (motor) nerve fibers

. In the reflex arc pathway, the sequence is as follows:

• Sensory receptors detect the stimulus.
• Afferent nerve fibers carry the signal to the spinal cord or brainstem.
• The integrating center processes the information.
• Efferent nerve fibers carry the motor signal to the effector.
• The effector then produces the reflex response, such as muscle contraction or gland secretion

Thus, the effector is the final component that executes the reflex action.