And the outer layer consists of strong fibrous proteins that give our pericardium its strength. So the outer layer is responsible for not only attaching the heart to different parts of the body, but it also protects the heart from physical damage. Now the inner portion of the pericardium is also known as the inner cirrus layer and cirrus comes from the word serum because this section actually contains of a fluid that resembles serum. Now our inner cirrus layer can actually be subdivided into two regions. We have the parietal and the visceral layer. Now the parietal layer of the inner pericardium is this orange layer right here, while the visceral layer of the inner pericardium is this inner layer of our pericardium shown in orange.