Regulation of blood pressure with baroreceptors NCLEXRN Khan Academy
Let’s talk about blood pressure homeostasis. And what homeostasis means is balance. So how is it that our body is able to create balance for our blood pressure? So this is the heart, and we’ve got branches of the aorta coming off of it. I haven’t been drawing these branches every single time,.
But this time I think it’s quite helpful to see. We’ve got here the left brachial artery, going out to the left arm, and we’ve got the left carotid artery here. And again, I’m writing left and right from the perspective of the person whose heart this is. And you’ve got here the right carotid artery and the right brachial artery.
So this is blood going to the right arm. And we’ve got blood going to the right neck. One interesting thing, if you look at the right carotid, is that it bulges right here in fact, both sides do. And they bulge right before they split. And so that bulge is actually called the carotid sinus, right here.
And we call it that because a sinus is any cavity. And so this is the right carotid sinus, and this is the left carotid sinus. Another spot I’m going to talk about in this tutorial is the aortic arch, which is right there. So these three spots the two carotid sinuses and the aortic arch are really, really, interesting, and actually they’re very important for learning.
About how it is that our body is able to create balance in our blood pressure. So at the top I drew kind of a blowup version of the carotid sinus, and at the bottom is the aortic arch. And if you look closely under a microscope, you’d see nerve endings on the outer layer of the vessel. And so these nerve endings basically join up and form a nerve, and these on the carotid sinus.
Do the same thing. And they are basically going to form two large nerves that go off. And they send information about what’s happening in the blood vessel, specifically about stretch. So as blood is pulsing through this vessel right here, this carotid sinus, or as it’s pulsing through the aorta, even, that wall is being stretched out.
And as it gets stretched out, these nerves they’re very special nerves, they’re called baroreceptors. Baro, meaning pressure, and they’re receptors for pressure, so they’re baroreceptors. These baroreceptors are feeling the effects of stretch. And what they do is, they send a signal down the nerve that tells the brain how much stretch is happening.