Introduction to the Anatomy of the Heart

00:01 We'll continue right into the basic structures of the heart now.

00:05 General organization, how is it put together? What about those valves and what about those conduction system things? Hang on, we're going to be there.

00:15 So the heart, actually, it looks nothing at all, like the typical appearance that we see when we think of a heart.

00:22 Hopefully going forward as young doctors to be, you will think of the heart looking more like this.

00:28 And this is still kind of a schematic representation, again, doesn't look anything particularly like that other structure that we see on Valentine's Day cards and when we think of being in love.

00:41 Whatever.

00:42 So we have a heart here, we have various structures, we have a superior vena cava and the inferior vena cava dumping their contents into the right atrium.

00:50 Again, this is deoxygenated blood returning from the body.

00:54 That right atrium, then dumps its contents into the right ventricle, which will then squeeze it out through the pulmonary artery to the lungs, where it becomes oxygenated.

01:04 That returns through the pulmonary veins, to the left atrium, left atrium, then dumped into the left ventricle, left ventricle will pump out through the aorta.

01:15 Now, the way that we think about the heart is that the stuff at the top is the base.

01:21 And the stuff at the bottom is the apex.

01:24 That's because roughly, the heart is a triangle.

01:29 And the apex of the triangle is down at the bottom, and the base of the triangle is up at the top.

01:35 So it's kind of counterintuitive.

01:37 It just is what it is.

01:39 And now you know how to refer to the heart base versus the apex.

01:44 Okay, this is a little bit better representation of what the heart looks like, it's not quite so schematized.

01:49 And in fact, you now can't see the vessels on the surface of the heart, they're usually buried within the epicardial fat, that kind of white yellow tan material over the surface of the heart.

02:01 Same structures, we're just giving you a different representation, we're going to work off this model.

02:07 Here's what it looks like in real life.

02:08 This is what I deal with day in and day out in my practice as a cardiovascular pathologist, and autopsy pathologist.

02:17 And again, the same structures.

02:18 And we're looking on the left hand side at the anterior view of the heart, and on the right hand side at the posterior view of the heart.

02:24 And I would encourage you to kind of just pause this and look at the different kind of labels to make sure that you are oriented appropriately.

02:35 Moving on, let's look at the heart in a slightly different way.

02:38 So we've been looking at it kind of on the exterior surface, let's cut into it.

02:43 So this is a transverse section, that's as if I took a blade and went this way through the heart in my chest.

02:50 Okay, and on the right hand side is what that looks like.

02:54 So you can begin to see that there is a different quality to the muscle in the right ventricle versus the left ventricle.

03:04 The bottom of the slide is the anterior wall so that would face forward.

03:09 The top is the posterior wall, and this is all a transverse plane, the left ventricle lumen is slightly bigger, shown here and the thickness of the wall is slightly greater.

03:23 In fact substantially greater because we need to pump at a much higher pressure from the left ventricle versus the right ventricle.

03:31 Between the two ventricles is the interventricular septum.

03:36 This is really pretty much still a continuum of the doughnut of ventricle wall that is the left ventricle.

03:43 But it will also contribute to the motion and the ejection coming from the right ventricle.