The carotid sinus contains:

a. baroreceptors.

b. chemoreceptors.

c. metabolic controls.

d. smooth muscle cells.

Video transcript

Welcome everyone. Our next question says, the carotid sinus has numerous stretch receptors that are sensitive to changes in which of the following factors. A blood's oxygen concentration, B, body temperature, C hormone concentration or D arterial blood pressure. So, let's think about what stretch receptors would be useful for particularly in the context of the carotid sinus. So the carotid sinus is a dilated segment of artery just below the carotid artery in the neck. So we're talking about within a blood vessel, what would a stretch receptor be important for? But what would make the blood vessel stretch, increased blood pressure or then they could also sense if there's decreased blood pressure and it's not stretching so much. And indeed, that is what the stretch receptors or barrel receptors are for. They sense changes in choice d arterial blood pressure. This of course is really important in this area because this is the blood supply going up to the brain. And obviously, the body, it's very important to maintain a proper steady blood flow to the brain, not too high a blood pressure and not too low. So you have these specialized burial receptors that sense drops or rises in blood pressure and send signals to the brain which men make adjustments. So you have this whole cycle going where these barrel receptors send signals to the cardiovascular control centers of the brain resulting in adjustments to regulate blood pressure. So things like slowing or increasing the heart rate or causing vasoconstriction or vasodilation. When we look at our other answer, choices, um choice, a blood's oxygen concentration, choice c hormone concentration, the body does have receptors that sense those things to help the brain control them. But those would be chemo receptors, not stretch receptors and same with choice B body temperature that would be sensed by thermo receptors. So there are receptors for all these things, but that's not what stretch receptors do. They're there. The walls of the blood vessels are stretching or constricting and that's helping to monitor that arterial blood pressure. So choice D is our correct answer here. See you in the next video.