Electrical Conduction System of the Heart Cardiac | SA Node, AV Node, Bundle of His

hey everyone this is sarah with register nurse orange comb and today we're going to be talking about the electrical system of the heart you may encounter this topic in your anatomy and physiology class pathophysiology class or some class in nursing school as a nurse you need to know the basics of how the heart conducts electrical impulses to generate the PQRS way that you see on EKG strips so in this video I'm going to go over how the electrical system works where it's located and hopefully give you a better understanding of how electrical system works in nursing school I had a difficult time with this but once I actually learned how it worked and looked at where every part of it was located in the heart I began to grasp it I think learning the best is actually looking at the material and visualizing it and understanding it and formulating it and making it concrete in your head so here we go we're going to start and first we're going to go over the pathways as you see this drawing over here and then I'm going to compare it to what it looks like in the heart and give you some little facts that you need to remember for tests because a lot of tests test you on certain questions and I want to hit the highlights of that and then when we're done with this quiz go to our website registered nurse or in comm and take the quiz that's called electrical system of the heart you go the homepage click the slider you can get to that quiz and you can test your knowledge on the electrical system all those questions that are on the on the quiz you may see on an exam in school so let's get started okay from the strolling we are going to start in the SA node everything starts in the SA node that is your sign sinoatrial node it will branch off into the Bachmann's bundle then the electrical impulses are conducted down through what are called internodal pathways these are your pathways which sends an impulse down to your Atrio ventricular node which is an AV node the AV node since it's impulses down through what's called the bundle of his the bundle of his branches off into two bundle branches you have the right bundle branch which is going to affect the right side of the heart and then you have the left bundle branch which will affect the left side of the heart and those bundle branches branch off into water called Purkinje fibers and this helps deliver what's called depolarization of the ventricle depolarization another word is contraction always like that confusing nursing school so let's go over it whenever it says ventricular or atrial depolarization that means contraction of the muscle and then you might also see atrial and ventricular repolarization that means the muscle is resting so it contracts and then it rests okay so repolarization is resting you can remember that by resting is spelled re STI ng and repolarization re so remember resting and repolarization that way okay so that is how their lexical system works now let's look over into a diagram of the heart and see where these areas are located because where they're located is where they deliver their jaw back for instance the SA node is located in your right atrium this is your right atrium your SA node conducts what's called these polarization of atriums it causes your atriums to contract when they contract you go C on through the internet'll pathways out electricity and hits AV node your AV node is located in the intro septum area this is between both of your atriums and then it all it claps let them to let happen because what happens whenever that delay happens it allows those valves to close all the way and let the blood shoot through so you don't have backup of blood so the AV node allows that delay to happen and then when that delay happens it sends it down through the bundle of his which will be in between your ventricles your bundle of hiss is located between your intra ventricle septon which is this area right here so you have the AV node in this area and then the bundle of his will go down into the intro ventricle septum and branch off into your right and left bundles and this is your right side of the heart and that's your left side of the heart so you have your bundles going up through there and then your Purkinje fibers will go over the ventricular tissue and allow that contraction to happen so that sometimes I just think it's easier just seeing how the electrical system works and where it's actually located in your heart because each like on a test you're going to be asked what is the SA node what does it do the SA node contracts have been the atriums and you would know that because the SA node is located in the right atrium so let's just go over some facts that you would have to know about each of these conduction pathways to help you on your test so first let's go over the SA node your SA node which is called the sinoatrial node it is located in the right atrium which is right here the SA node is known to be the pacemaker of the heart so on the test you may see you may hear what is the pacemaker apart it's the SA node the SA node what it does is it causes your atrium to contract okay so it's responsible for atrial depolarization polarization means contraction it beats this is also another common test question it beats at 6,200 beats per minute which is a normal heart rate okay so that's why it's known as the pacemaker the SA node forms your P wave and we'll be going over this in depth in the next video I'm making but I just wanted to touch on this because your P wave represents atrial contraction so when you're looking at the P wave the SA node is responsible for that because that's representing atrial contraction okay now let's go over the AV node okay now regarding the AV node the AV node also known as atrial ventricular node is known as the gatekeeper of electrical conduction system the SA node was known as the pacemaker and the AV node is known as the gatekeeper that's usually another test question so you probably want to remember that it feeds at forty to sixty beats per minute so if the SA node failed the AV node would take over and beat at forty to sixty beats per minute that's usually another test question the test question may say which part of the heart beats ad electrical system beats at forty to sixty beats per minute it's the AV node the AV node allows a cloud a delay the delay between the SA and the AV node because remember that AV that SA node is contracting the atrium when it contracts the atrium it shoots blood down through your tricuspid valve into your right ventricle and because of that delay you want all that blood to empty completely into the ventricle because if not you would have backflow of blood so the AV node just is like the gatekeeper and allows the blood to completely empty from atrium into the ventricles so you don't have blood just going back front to the atrium because you want all that blood to pull back into the ventricles so that's the really the main goal of the AV keep of the AV node is to be the gatekeeper and allow the blood to completely empty into the ventricles now let's talk about the bundle of His and left and bundle branches okay now to the bundle of His left bundle and right bundle and the Purkinje fibers okay first let's talk about the bundle of His you have the bundle fuse which is right here it is located on in the intraventricular septum so that just as a fancy word for in-between the ventricles which these are your right and left ventricles so your bundle kiss is located down in this area now the bundle of His it will branch off into two bundles the right bundle and the left bundle so the right bundle is going to go to the right side of the heart and the left bundle is going to go to left side of the heart and these bundles spread out into fibers which are surrounding your been trickier ventricle muscle tissue so whenever that happens you get depolarization of the ventricles so you have the AV node who shoots electrical electricity down through the bundle of his the left bundle branch left and right bundles and in the Purkinje fibers and that causes a depolarization of the ventricles which is causing ventricles to contract so when that happens you have that and then it will be formed that forms your QRS so when your ventricles contract you're seen you're seeing the Purkinje fibers the bundle of His and the right left bundle is all contracting and that's making your QRS on your EKGs footway so just like the SA node made the P wave the contraction of the atrium now your visual ventricles are contracting and that's making your QRS and when the Purkinje fiber and fibers beat they beat it 20 to 40 beats per minute so that's probably another thing you want to remember is when everything else fails if the SA node failed in a patient or the AV node the Purkinje fibers could take off it's not going to be very good for that patient they need some intervention but it will be at 20 to 40 beats per minute and so just remember that that is forming your QRS now let's talk about the T wave the T wave is related to your QRS because the T way believe it or not those ventricles are so big whenever they can track which is depolarization you're going to get relaxation because you contract and then you relax and the T wave is whenever your ventricles are relaxing the ventricles are so big they call such a big impulse that you get the T wave and it's called ventricle repolarization which is just relaxing so that's what your T wave is that's just the basic rundown on your PQRS s that I just wanted to go over with you but in the next video we're going to go in more depth so that is the electrical system of your heart the down-and-dirty of it how it works and what you need to know is an R the basis and to give you some ideas of some things that you may encounter on a test so if you like this video please give it a thumbs up and go to our website remember registered nurse Orion calm and take the quiz to see how well you grasped this material and thank you so much for watching and have a great day

Channel: RegisteredNurseRN

Views: 1,371,996

Keywords: Electrical Conduction System Of The Heart, sa node, nclex, Heart (Anatomical Structure), hesi entrance exam anatomy, nursing school, hesi anatomy and physiology, how to memorize heart, registerednursern.com, hesi anatomy, heart blood flow, electrical system of the heart, quiz for the electrical system of heart, conduction system of the heart, cardiac conduction system, heart electrical system, sa node and av node, av node

Id: -X9rYD8zSQg

Length: 10min 51sec (651 seconds)

Published: Wed May 20 2015