External and Internal Anatomy of the Heart (Nursing)

00:01 Finally, the literal heart of the course, the heart itself.

00:06 We're going to start with a nice anterior view, with the pericardium removed, we're always going to keep in mind that the heart doesn't just look like this when it's sitting in the chest, it's covered by that pericardium.

00:18 So we can actually see, the pericardium has been cut here, as a reminder that it doesn't look like this.

00:25 We see the superior vena cava, the inferior vena cava, and what they're attaching to is the first part of the heart, the right atrium.

00:35 The right atrium is going to lead into the right ventricle, and eventually pump out the pulmonary artery out to the lungs.

00:43 You'll notice from an anterior point of view, though, we don't see as much left ventricle.

00:48 That's because the heart is not only a little bit off to the left, but it's also rotated a little bit so that it points to the left, so that from an anterior point of view, you see a lot more of the right heart than you do the left.

01:01 Regardless, we can make out there's a little bit of a line here, there's a little bit of fat, and that's actually our external marker for something called the interventricular septum, or the border between the two ventricles.

01:15 This point at the inferior portion of these ventricles is called the cardiac apex.

01:21 And the cardiac apex, again, doesn't just point straight down, it's sort of points down or inferior into to the left.

01:29 And the left ventricle is going to pump out the ascending aorta, which is going to arch and eventually become a descending aorta as it heads down towards the abdomen.

01:41 And before it does that, it's going to give those branches we just mentioned.

01:44 The brachiocephalic trunk, and then directly off of the aortic arch is the left common carotid and the left subclavian arteries.

01:54 If we swing around to not exactly posterior, not exactly inferior, sort of posterior inferior view, we're going to see some of the stuff we really couldn't see from the anterior view.

02:06 We again can still see the superior vena cava and the inferior vena cava and the right atrium for reference.

02:13 But now we can actually see a little bit of those branches of the pulmonary.

02:17 We see the left pulmonary artery and the right pulmonary artery.

02:21 We also can now see the pulmonary veins, these are very posterior structures.

02:26 You see them on the left and the right.

02:28 They're both feeding into the left atrium, which is really the most posterior of all of these structures.

02:35 And we can see a lot more of our left ventricle finally.

02:39 Again, the cardiac apex is pointing down into the left.

02:43 And here we can see the aortic arch as it was disappearing out of our anterior view as it's coming posteriorly and starting to turn downward as a descending aorta.

02:57 Now let's take a look at the internal structure of the heart.

03:01 Starting with the right atrium.

03:04 So what we've done here is cut a little flap so we can see the inner workings.

03:09 We have the superior vena cava, and the inferior vena cava draining into this right atrium with their deoxygenated blood.

03:17 But there's a third source of deoxygenated blood entering the right atrium, something called the coronary sinus.

03:24 And the coronary sinus is essentially where the venous drainage of the hearts own veins enter the heart.

03:32 Here there's a little bit of the tricuspid valve that's going to separate our right atrium from our right ventricle.

03:39 And our right ventricle we can't quite see yet but we know it's going to be a little bit more anterior and inferior than our atrium.

03:47 And it's going to pump out the pulmonary artery.

03:51 So let's take a look inside that right ventricle.

03:55 We have the blood coming in from the right atrium through the tricuspid valve.

04:01 And these cusps, there's three of them, as the name implies, are attached to the heart via these tenderness cords appropriately called chordae tendineae any that attached to finger like muscles on the right ventricle wall called papillary muscles.

04:17 And just like there's a tricuspid valve we have three papillary muscles.

04:22 One anteriorly, posteriorly, and one septal are located along the septum between the two ventricles.

04:30 And this is the interventricular septum here and if we were to poke our finger through or in congenital heart disease turn how the ventricular septal defect, we would end up directly into the left ventricle chamber.

04:43 The outflow of the right ventricle is through the pulmonic valve into the pulmonary artery and out into the lungs.

04:52 And here we see the aortic arch branching over that right branch of the pulmonary artery that we just can't see.

05:01 Now, let's switch around to the left side, and look at the left atrium and ventricles.

05:07 So here we see the pulmonary veins entering into the left atrium after having just got oxygenated blood from the lungs.

05:14 And here we have a mitral valve, it looks similar to the tricuspid valve, except instead of three cups, we have two.

05:22 We still have chordae tendineae, and we still have papillary muscles, but we only have two - the anterior and posterior sides.