Final answer:
Alpha-1 receptor stimulation increases BP, initiating a baroreflex that slows heart rate through parasympathetic stimulation, thereby limiting the increase in cardiac output. β-blockers reduce cardiac output by inhibiting β-1 receptors, which can lead to bradycardia if overprescribed.
Step-by-step explanation:
Stimulation of Alpha-1 receptors increases blood pressure (BP), which triggers a reflex slowing of the heart rate, known as the baroreflex. The baroreflex helps to limit the change in cardiac output (CO) by activating the parasympathetic nervous system, which in turn decreases heart rate and stroke volume through vagus nerve stimulation. This reflex mechanism is crucial in maintaining homeostasis. Medications like β-blockers target these processes. β-blockers, such as those prescribed for hypertension, work by inhibiting β-1 adrenergic receptors, thereby reducing heart rate, stroke volume, and ultimately cardiac output. It is important to prescribe them with caution, as overprescription can result in bradycardia or cardiac arrest.