Final answer:
The carotid sinus baroreceptors are the ones that monitor blood pressure affecting the brain, by initiating the baroreceptor reflex to adjust blood pressure and maintain cerebral perfusion. Option 1 is correct.
Step-by-step explanation:
The baroreceptors that monitor blood pressure affecting the brain are the carotid sinus baroreceptors. These specialized stretch receptors are located at the base of the internal carotid arteries and respond to changes in arterial blood pressure by sending impulses to the cardiovascular centre.
They play a crucial role in regulating blood pressure by initiating the baroreceptor reflex, which adjusts the balance of sympathetic and parasympathetic stimulation to either increase or decrease blood pressure as necessary. The carotid sinus baroreceptors, therefore, help maintain cerebral perfusion and overall cardiovascular homeostasis. Other baroreceptor locations, such as the aortic arch, monitor blood pressure in general, but not specifically blood pressure affecting the brain.