A reflex arc is a pathway that controls reflexes. It is like a circuit; it begins with a sensory neuron at a receptor and end with a motor neuron at an effector.
''IPSILATERAL " is a term used for a reflex arc and it simply means; on the same side as another thing or structure. For example, the case in the question when one's muscle in the LEFT arm contract, apparently it will pull one's LEFT hand away from an hot object or material
