Certified Ophthalmic Medical Technologist (COMT) Practice Exam

Which neurotransmitter substance do parasympathomimetic agents simulate the effect of?

1. Aldosterone

2. Norepinephrine

3. Acetylcholine

4. Serotonin

The correct answer is: Acetylcholine

Parasympathomimetic agents mimic the effects of acetylcholine, which is the neurotransmitter that primarily operates in the parasympathetic nervous system. This system is responsible for promoting the "rest and digest" functions of the body, which includes actions like slowing the heart rate, increasing glandular secretions, and contracting smooth muscles, particularly in the gastrointestinal tract. Acetylcholine acts on various receptors, including muscarinic and nicotinic receptors, which are key in mediating the actions of parasympathetic stimulation. When parasympathomimetic agents are administered, they enhance the effects of acetylcholine or simulate its action, leading to outcomes such as increased salivation, reduced heart rate, and bronchoconstriction. The other choices do not align with the function of parasympathomimetic agents. Aldosterone is a hormone involved in fluid balance and blood pressure regulation, norepinephrine is the primary neurotransmitter of the sympathetic nervous system that generally prepares the body for a fight or flight response, and serotonin is mainly involved in mood regulation and does not play a direct role in the actions mediated by the parasympathetic nervous system. Thus, acetylcholine is the key neurotransmitter simulated by paras