pericardium
/ˌpɛrɪˈkɑrdiəm/
noun
- The double-layered sac of tissue that surrounds the heart and helps protect and support it.
- Inflammation of the pericardium is called pericarditis.
- The pericardium keeps the heart in place and prevents it from overexpanding.
- The surgeon carefully cut through the pericardium to access the heart.