Final answer:
Antipsychotic medications mainly block dopaminergic receptors to treat symptoms of schizophrenia by preventing dopamine overstimulation. Different drugs like agonists and antagonists either activate or block these receptors to regulate neurotransmitter imbalances, determining the therapeutic effects on disorders like Parkinson's disease.
Step-by-step explanation:
Most antipsychotic medications act by blocking dopaminergic receptors (Option B). These medications are designed to antagonize the dopamine neurotransmitter, thereby inhibiting the overstimulation of dopamine receptors, which is often associated with certain symptoms of schizophrenia. It is important to note that while these drugs are antagonists that block the receptors, there are other compounds known as agonists that activate them instead. In contrast, Parkinson's disease is treated with dopamine agonists that mimic the effects of dopamine to compensate for the low levels of this neurotransmitter in such patients.
As for drugs affecting both divisions of the autonomic system, they could interact with various neurotransmitter receptors such as nicotinic, muscarinic, α-adrenergic, and β-adrenergic. Each of these plays a different role in mediating the actions of the autonomic nervous system.