What is Pericardium, definition and function. Pericardium is a tough, two-layer membranous sac that encloses the HEART. The pericardiumâs fibrous outer layer, called the fibrous pericardium, protects the heart from contact with the chest wall and other structures in the chest, including the LUNGS and the sternum.he inner layer of the pericardium is a filmy envelope. Its two surfaces are the parietal pericardium, which contacts the fibrous pericardium, and the epicardium, which covers the MYOCARDIUM somewhat like a wet tissue. Inside the envelope is a watery fluid that lubricates the heart.
Roman Empire Timeline. Timeline Description: The Roman Empire was one of the greatest civilizations in history. It began in Rome in 753 BC. Rome controlled over two million square miles stretching from the Rhine River to Egypt and from Britain to Asia Minor. This timeline highlights the major events in the history of Ancient Rome.
The Western Empire ceased to exist in 476 CE when the Goths took control, but the Empire continued on in the east, with its capital in Constantinople and was commonly known as the Roman Empire. 1  Rome began as a kingdom around 800 BCE and was then a republic, before becoming an empire. The first Roman Emperor was Octavius, who took the imperial name Augustus. He became emperor in 31 BCE. The Roman Empire split into a Western Roman Empire and an Eastern Roman Empire in 395 CE. The Western Empire ended in 476 CE. The Eastern Empire, or Byzantine Empire, ended in 1453. Depending on how you define the Roman Empire: The united empire lasted 426 years; The Western Empire lasted a further 81 years, for a total of 507 years