Question

A doubled walled protective sac called the _________________encloses the heart.

Answer 1

Pericardium:

1. The pericardium, also called pericardial sac, is a double-walled sac containing the heart .
2. The fluid present between the pericardium is called pericardial fluid.
3. This fluid protects the heart from sudden shocks and jerks.

Final answer: A doubled walled protective sac called the pericardium encloses the heart.