Conduction System of the Heart (Nursing)

00:01 Finally, let's talk about how the heart does its job in a coordinated fashion.

00:06 That's the job of the cardiac conduction system.

00:10 Now, the cardiac conduction system, it's easy to confuse with nerves that you have in the rest of the body because it's a muscle and generally nurse tell muscles what to do.

00:22 Not in the heart. In fact, the conduction system itself, although it sounds like they're going to be nerves, they're actually heart muscle cells that have just been modified for conduction rather than contraction.

00:35 Nerves can influence the heart and they can innervate the heart and do other things.

00:39 But the conduction of the heart itself is all carried out by heart muscle.

00:46 And it all starts with the sinoatrial node or SA node back in the right atrium. That's the pacemaker area.

00:55 That's what says, this is how fast we're going to go.

00:58 It can be modified by hormones and nerves of what we call the autonomic nervous system.

01:04 But generally, the speed is set here.

01:09 That conduction then has to go through the ventricles via what are called internodal tracks, through the right atrium and a particular one going through the left called Bachmann's bundle.

01:20 But then they all coalesce at another node, hence the term internodal tracks at the junction of the atrium and ventricle called the atrial ventricular or AV node.

01:33 From there, it can go through a fibrous area that insulates the heart as the Bundle of His.

01:41 And that's really important because we don't want the ventricles to be stimulated directly from the atria, we want it to come just as it's supposed to.

01:49 That's why everything funnels down to this Bundle of His that then reaches the ventricular septum on either side to form a left bundle branch or a right bundle branch.

02:01 So here we have the SA node, generating the impulse So here we have the SA node, generating the impulse traveling through the atria via these internodal tracks to reach the AV node.

02:12 And from there, the AV node says, it's okay to move on through the Bundle of His out towards the right and left bundle branches of the septum and eventually through the hearts Purkinje Network.