A doctor places drops in the eyes to dilate the pupils for an examination. The type of drug that is used is a(n) ________ drug.
1) sympathomimetic
2) muscarinic blocking
3) adrenergic activating
4) cholinergic activating
A) 1, 2
B) 3
C) 4
D) 1, 2, and 3
E) 2, 4

Question

A doctor places drops in the eyes to dilate the pupils for an examination. The type of drug that is used is a(n) ________ drug.
	1) sympathomimetic  
	2) muscarinic blocking
	3) adrenergic activating 
	4) cholinergic activating
A) 1, 2
B) 3
C) 4
D) 1, 2, and 3
E) 2, 4

Quizplus · Accepted Answer

The type of drug that is used to dilate the pupils for an examination is a sympathomimetic or a muscarinic blocking drug. These drugs work by either mimicking the action of the sympathetic nervous system (sympathomimetic) or by blocking the muscarinic receptors of the parasympathetic nervous system (muscarinic blocking).
Sympathomimetic drugs (1) stimulate the sympathetic nervous system, which can lead to pupil dilation (mydriasis) among other effects. An example of a sympathomimetic drug used for pupil dilation is phenylephrine.
Muscarinic blocking drugs (2), also known as antimuscarinic drugs, block the action of the neurotransmitter acetylcholine at muscarinic receptors, which are part of the parasympathetic nervous system. This blockage results in pupil dilation. An example of a muscarinic blocking drug used for this purpose is tropicamide.
Therefore, both sympathomimetic and muscarinic blocking drugs can be used to dilate the pupils for an eye examination.

A Doctor Places Drops in the Eyes to Dilate the Pupils