Question

Your body compensates for increased mean arterial pressure through the following

Select one:

a. Arterial baroreceptors induce a rapid change in blood pressure and the kidneys increase water excretion for long term reduction in mean arterial pressure

b. Renin is released into the circulation

c. Increased venous return

d. Glomerular filtration rate is decreased

Answer 1

Correct option is option A.

Explanation- baroreceptors are stretch receptors which are present at two locations- carotid and aortic arch. These receptors sense any increase or decrease in blood pressure and send signals to brain to take compensatory actions.

When there is increased blood pressure, the baroreceptors sends signal to brain. The brain through various pathway bring following changes to bring blood pressure to normal-

Brain send signals to kidney to excrete more water. If water content of blood decreases, then the total volume of blood decreases which eventually reduces blood pressure. This is a long term regulation of blood pressure.

Brain also sends signal to blood vessels and cause vasodilation. Vasodilation of blood vessels cause reduction in blood pressure. This is a short term regulation of blood pressure.

Option 2 in incorrect because secretion of renin will increase the blood pressure more via renin angiotensin pathway. Renin is released when blood pressure is reduced.

Option 3 in incorrect because increase venous return will increase blood volume in heart. And since blood volume is increased, then heart will pump the blood with more force and blood pressure will increase.

Option 4 is incorrect because if GFR is reduced, then blood volume will remain high. And high blood volume means high blood pressure.