What term refers to agents that temporarily block nerve signals?

The term that refers to agents that temporarily block nerve signals is anesthetics. Anesthetics work by interfering with the transmission of nerve impulses, which can result in a loss of sensation, pain relief, or sedation. This mechanism is crucial in medical and surgical procedures where it is necessary to prevent the patient from feeling pain.

In contrast, the other options describe different categories of substances. Asphyxiants are gases or vapors that can cause suffocation by displacing oxygen, irritants are compounds that provoke inflammation or discomfort in the tissues upon contact, and pests refer to unwanted animals or insects that can harm crops or spread disease. None of these options relate to the blockage of nerve signals in the way that anesthetics do.