Describe the pericardium and distinguish between the fibrous and the serous pericardia relative to histological structure and location.

Video transcript

Welcome back. Everybody. Here's our next question. Which layer of the pericardium is tough and fibrous, providing protection and anchoring the heart in the chest. A visceral pericardium B, parietal pericardium, C, epicardium or D myocardium. Well, to start this, we should remember that the pericardium is this sort of double walled sack that surrounds the heart, providing protection. And we don't have to look at the whole structure to get the answer if time were of the essence here of this question because we can kind of logic our way to it if we think about, well, what's the layer of that's tough and fibrous, protecting the heart, anchoring the chest, that'd be the outermost layer. And that's choice B the parietal pericardium, the word visceral means that an inner lining. And so we know that the visceral pericardia must be an inner lining. But to understand our other answer choices and think through this thoroughly, I'm going to draw a really rough diagram here of the different layers of this pericardium. So the outer fibrous layer which I've drawn as a series of lines to signify these tough fibers is the parietal pericardium, which is the answer that we're looking for and it anchors the heart in the chest. It's to the diaphragm and to the sternum. So that's anchoring the heart in the chest wall and those tough fibers provide protection for the heart. So that's our pa parietal pericardium, which is our answer. But if we want to look at our other answer, choices, uh choice a the visceral pericardium underneath the parietal pericardium, we have this c pericardium, uh two membrane layers filled with a small amount of serious fluid that has a parietal layer that adjoins the parietal per cardi and then a visceral layer. And that also is called the epicardium. So the visceral pericardium or epicardium are this inner layer of the pericardium. It's a serious membrane and it directly covers the heart's surface, but it's not this tough fibrous outer surface that anchors the heart. So that's why choice A and choice C are not correct. And then finally, choice D the myocardium, the myocardium is this inner layer of heart muscle cells below that visceral layer of c pericardium right over the heart chamber. And it's what actually is responsible for those muscle contractions of the heart, but it's not the outer fibrous layer. So it is not our correct answer. So again, the tough fibrous layer that provides protection and anchors the heart. This choice be the parietal pericardium. See you in the next video