Question

If arterial blood pressure increases to 140/85 mmHg what is the correct response if the blood vessels are signaled by the brain?

a.Send more messages through sympathetic nerves that innervate pacemaker cells
b.Vasodilation to increase lumen size
c.Send fewer messages through sympathetic nerves that innervate pacemaker cells
d.Vasconstriction to decrease lumen size
d.All the choices are correct

Answer 1

When arterial blood pressure is elevated, the body responds by decreasing sympathetic stimulation and increasing parasympathetic activity, leading to vasodilation and reducing blood pressure.

Step-by-step explanation:

If arterial blood pressure increases to 140/85 mmHg, the correct response from the blood vessels signaled by the brain would be vasodilation to increase lumen size. When blood pressure rises too high, the baroreceptors are stretched more tightly and initiate action potentials at a higher rate which triggers parasympathetic stimulation of the heart, leading to a decrease in cardiac output. At the same time, sympathetic stimulation of the peripheral arterioles will decrease, resulting in vasodilation. This helps lower the blood pressure back towards normal levels.