MRCP UK EXAMINATIONS

Detailed explanation-1: -The neurotransmitters involved in the ANS are acetylcholine, norepinephrine, and epinephrine. Preganglionic neurons of the sympathetic and parasympathetic divisions and postganglionic neurons of the parasympathetic nervous system utilize acetylcholine (ACh).

Detailed explanation-2: -Acetylcholine is the chief neurotransmitter of the parasympathetic nervous system, the part of the autonomic nervous system (a branch of the peripheral nervous system) that contracts smooth muscles, dilates blood vessels, increases bodily secretions, and slows heart rate.

Detailed explanation-3: -Parasympathomimetics are a class of medications that activate the parasympathetic nervous system by mimicking or modifying the effects of acetylcholine. These drugs include muscarinic receptor agonists (direct-acting parasympathomimetics) and acetylcholinesterase inhibitors (indirect-acting parasympathomimetics).

Detailed explanation-4: -Acetylcholine is a neurotransmitter that plays a role in memory, learning, attention, arousal and involuntary muscle movement. Medical conditions associated with low acetylcholine levels include Alzheimer’s disease and myasthenia gravis.

Detailed explanation-5: -Parasympathetic nerves traveling within the vagus nerve release acetylcholine to act upon M2 and M3 muscarinic receptors on airway smooth muscle. The nerve terminals also express autoinhibitory M2 muscarinic receptors that respond to released acetylcholine to inhibit further neurotransmitter release.