Which system is primarily affected by organophosphates?

• A. Digestive system
• B. Nervous system
• C. Cardiovascular system
• D. Endocrine system

Answer: (B)

Organophosphates primarily affect the nervous system. These compounds are a group of chemicals used in pesticides and can inhibit the enzyme acetylcholinesterase. This enzyme is crucial for breaking down acetylcholine, a neurotransmitter that transmits signals in the nervous system. When acetylcholinesterase is inhibited, acetylcholine accumulates, leading to overstimulation of nerve receptors. This can manifest in a range of symptoms, including muscle twitching, respiratory distress, and in severe cases, can result in respiratory failure and death due to the overwhelming stimulation of the nervous system.

Although organophosphates can have indirect effects on other systems, such as causing gastrointestinal symptoms or cardiovascular responses due to the stimulation of the nervous system, their primary and most direct impact is on neuronal function and transmission.