Which structure is at work when the body deals with reflex actions?

Answer;

The spinal cord

The structure that is at work when the body deals with reflex actions is the spinal cord.

Explanation;

A reflex action involves a nervous pathway called a reflex arc.

A reflex arc starts off with receptors being excited by a stimuli such as pain. They then send signals along a sensory neuron to the spinal cord, where the signals are passed on to a motor neuron. As a result, one of the muscles or glands (effector cells) is stimulated

The nervous system is at work when the body deals with reflex actions. The nervous system is the central system for all movements, especially those originating from the spinal chord.