pericardium
noun [ C ] anatomy specialized uk/ˌper.ɪˈkɑː.di.əm/ us/ˌper.ɪˈkɑːr.di.əm/ pericardia
心包
the double layer of tissue that surrounds the heart
The function of the pericardium is to protect and lubricate the heart. 心包的作用是保护和润滑心脏。