Which structure connects the heart valves to the papillary muscles?

Neurogenic heart receives stimulus for contraction from . . . . . . fibres.

In a rabbit,oxygenated blood flows from:

Given below are two statements.
Statement $I$: Visceral layer of serous pericardium forms the outer wall of human heart.
Statement $II$: Epicardium is formed of a thick layer of cardiac muscles.
In the light of the above two statements,choose the correct answer from the options given below.

The first heart sound is caused by the closure of which valves?

How can the origin and conduction of the heartbeat be represented?