What key characteristic of a nerve agent distinguishes it from a blister agent in terms of its immediate physiological effect?

The key characteristic that distinguishes a nerve agent from a blister agent, in terms of immediate physiological effect, is that nerve agents disrupt the nervous system leading to rapid incapacitation and potential death, while blister agents primarily cause severe skin, eye, and respiratory tract injuries, resulting in debilitating but generally slower-acting effects. Nerve agents, such as Sarin or VX, inhibit the enzyme acetylcholinesterase, which is crucial for nerve function. This inhibition causes an overstimulation of nerve endings, leading to symptoms like convulsions, respiratory failure, and loss of consciousness within minutes of exposure. Blister agents, like mustard gas, on the other hand, cause severe blistering of the skin and damage to the eyes and airways. While extremely painful and debilitating, the effects of blister agents typically take hours to manifest, and death, if it occurs, usually results from secondary infections or respiratory complications, not from the immediate disruption of vital bodily functions as with nerve agents. Therefore, the immediate impact of nerve agents is on the nervous system causing rapid incapacitation and death, while blister agents primarily cause severe tissue damage with delayed and less immediate effects.