The pericardium is a double-walled sac that contains the heart and the roots of the great vessels. The outer wall of the pericardium is composed of dense connective tissue. The portion of the inner wall of the pericardium that is in contact with the heart (but not in contact with the great vessels) is the epicardium. The epicardium contains the blood vessels supplying blood to heart muscle (the coronary arteries) as well as nerve fibers.
It's been three years since the world learned of Michael Jackson's death. Photos: Remembering the King of Pop Three Years Later.
21 November 2013. Michael Jackson (USA) may be the undisputed king of long-form music videos, but even Ghosts, his spine-tingling, 39-min 32-sec epic from 1997, was spooked in November 2013 when Pharrell Williams (USA) released the world's first 24-hour music video, for his single Happy, on the website 24hoursofhappy.com.