What is the primary effect of cyanide on the body?

The primary effect of cyanide on the body is its ability to inhibit the utilization of oxygen at the cellular level. Cyanide affects the mitochondria's ability to use oxygen to produce ATP, which is the energy currency of the cell. It specifically binds to cytochrome c oxidase, a crucial component of the electron transport chain, effectively halting aerobic respiration and leading to a situation where cells cannot use oxygen to produce energy.

This inability to utilize oxygen can result in cellular asphyxiation, even when oxygen levels in the blood are adequate. While other answers present effects related to cyanide exposure, they do not accurately capture cyanide's primary mechanism of action, which revolves around oxygen utilization impairment at the mitochondrial level.