functional toxic response

Toxic responses to substances can be classified as either morphological (structural) or functional, or a combination of both. Morphological responses involve physical changes to an organ, which then impacts its function. For example, prolonged exposure to silica dust can lead to silicosis, where nodules form in the lungs, impairing their ability to expand and exchange oxygen.1

Functional responses, on the other hand, occur when a substance affects an organ's function without altering its structure. An example is exposure to malathion, which inhibits the enzyme acetylcholinesterase, leading to an overstimulation of the parasympathetic nervous system and potentially fatal respiratory depression. The nervous system is particularly sensitive to toxic damage. Toxic responses can also be local, occurring at the site of contact, or systemic, affecting tissues away from the point of entry. Some toxic effects are reversible, while others, like the formation of silicotic nodules, are irreversible.1234