Question 3#

Chemoreceptors in the aorta and carotid bodies do NOT sense which of the following? 

A. Changes in O2 tension
B. H+ ion concentration
C. HCO3 - concentration
D. Carbon dioxide (CO2) levels

Correct Answer is C


Chemoreceptors in the aorta and carotid bodies are sensitive to changes in O2 tension, H+ ion concentration, and carbon dioxide (CO2) levels. Stimulation of the chemoreceptors results in vasodilation of the coronary arteries, slowing of the heart rate, and vasoconstriction of the splanchnic and skeletal circulation. In addition, a variety of protein and nonprotein mediators are produced at the site of injury as part of the inflammatory response, and they act as afferent impulses to induce a host response.