Final answer:
The statement that atropine is a sympathetic blocking agent is false. Atropine is an anticholinergic drug that blocks muscarinic acetylcholine receptors, reducing parasympathetic nervous system activity and indirectly allowing increased sympathetic activity.
Step-by-step explanation:
Atropine is not a sympathetic blocking agent; therefore, the statement is false. Atropine is an anticholinergic drug that acts as an antagonist to muscarinic acetylcholine receptors, which are part of the parasympathetic nervous system. It works by blocking the effects of excess acetylcholine, a neurotransmitter that activates the parasympathetic response. Since the sympathetic and parasympathetic systems are components of the autonomic system that have generally opposite effects, atropine can be understood to indirectly increase sympathetic activity by inhibiting parasympathetic signals.
Drugs like phenylephrine mimic the actions of adrenergic molecules and are called sympathomimetic drugs because they stimulate sympathetic activity. Conversely, drugs such as ß-blockers are considered sympatholytic because they block adrenergic activity, which can reduce sympathetic effects on the target organ.