As the effects of a nerve agent progress, what muscular action will occur?

The correct choice reflects the physiological response related to the effects of nerve agents on the nervous system. Nerve agents, which are toxic compounds that interfere with the normal functioning of the nervous system, inhibit the enzyme acetylcholinesterase. This leads to an excessive accumulation of acetylcholine at the neuromuscular junction, resulting in prolonged contraction of the muscles.

This sustained contraction occurs because the muscles are unable to relax due to continued stimulation by acetylcholine. As a result, the muscles may experience a state of continuous activation, which can manifest as muscle rigidity or spasms. It is essential to understand that while muscle paralysis can be a later effect or result of severe toxicity, the initial and prominent feature of nerve agent exposure is prolonged contraction, highlighting the disruptive effect these agents have on neuromuscular communication.

In contrast, muscle twitching and rapid fatigue may occur at different stages or under different conditions but do not accurately capture the primary effect of nerve agents on muscular action in the acute phase of exposure. The muscular response to nerve agents is characterized primarily by sustained contraction rather than intermittent activity or gradual fatigue.