Structure of the Pericardium and the Great Vessels (Nursing)

00:01 Now let's start looking at that pump the heart.

00:04 But before we talk about the heart, we have to talk about what's around the heart or the pericardium.

00:12 So, the pericardium is this multi layered structure that protects the heart.

00:19 We have the heart muscle called the myocardium, inside the heart itself, just on top of that is something called a serous pericardium, with a visceral layer or visceral layer, directly attached to the surface of the heart.

00:36 It doubles back on itself to form a parietal layer of serous pericardium.

00:43 In between the two is a little bit of fluid called pericardial fluid.

00:47 Serous means watery. And so essentially, what these two layers are doing is producing a thin layer of pericardial fluid to reduce the friction between the heart and the pericardium, because it's constantly beating. It's contracting and it's expanding.

01:03 And it's doing that continuously, hopefully.

01:06 And you want to decrease the friction by having this pericardial fluid.

01:11 And beyond that, we have the fibrous pericardium sitting on top of the parietal layer.

01:17 And that's more of a thick, tough layer to help protect the heart.

01:23 Normally, the pericardial space only has a very small amount of fluid.

01:28 But in a lot of disease conditions, inflammation, heart attacks, and other things, you can have an excess called a pericardial effusion, where that fluid builds up.

01:39 And can actually start compressing the heart.

01:43 Now let's take a look at the great vessels.

01:46 When we say great vessel, we're talking about a vessel that attaches directly to the heart itself.

01:52 And what we've done here is take the heart out and cut around the pericardium.

01:56 So we can see the origins of these great vessels.

02:00 The first one to the right and superior of the heart is the superior vena cava.

02:04 Bringing back all of that deoxygenated blood from above the heart.

02:08 And then the inferior vena cava doing the same thing from below the heart.

02:14 We also have the pulmonary artery, which is going away from the heart out to the lungs, where blood can get oxygenated and come back via the right and left pulmonary veins.

02:26 And then finally, we're going to pump out through the aorta, all of that freshly oxygenated blood to supply the rest of the body.

02:37 So let's zoom out a little bit and look at some of the extensions of these great vessels.

02:43 So we have our superior vena cava here, and we see it's receiving a vein called the right brachiocephalic vein.

02:51 Now, we've seen the term brachial referring to arm in some of the other lectures cephalic refers to head.

02:58 So this is a vein receiving venous blood from the upper limb and the head and neck area.

03:05 We have a similar one on the left, which is quite a bit longer because the superior vena cava is over on the right side.

03:12 So this left brachiocephalic has to go a little bit further has to cross over the midline to get to the right side.

03:19 Going into the brachiocephalic.

03:20 So we have a right subclavian vein training the upper limb and a left subclavian vein doing the same on the left.

03:28 Then we have the internal jugular veins, training the head and neck area.

03:36 If we switch gears and think about the aorta, the first thing we see is a very large branch called the brachiocephalic trunk.

03:46 Brachiocephalic kind of tells us where it's going.

03:49 So we have a right subclavian artery going out to the upper limb and a right common carotid artery going up to the head and neck.

03:58 But there's a little thing here that you should note that's asymmetric compared to the venous system.

04:03 So we don't say left or right brachiocephalic trunk, we just say brachiocephalic trunk.

04:08 That's because on the left, there is no brachiocephalic trunk.

04:11 The left common carotid artery and the left subclavian artery come off directly from the aorta.

04:18 So it's asymmetric, we only have the one brachiocephalic trunk, and it's supplying stuff on the right side.