Cardiac muscles contract:

Purkinje fibers are located in the following structure/s:

Where is the impulse for the heartbeat generated?

The pericardium and the pericardial fluid help in

The apex beat of the heart is synchronous with:

When the heart of a frog is removed from the body,it continues to beat for some time. Select the correct statement$(s)$ from the following:
$(i)$ The frog is a cold-blooded animal.
$(ii)$ The frog does not have a heart-based circulatory system.
$(iii)$ The heart has myogenic properties.
$(iv)$ The heart is self-excitable.