Which of the following statements are wrong?
(i) The heart is protected by a double-walled membranous bag called the pericardium.
(ii) Bundle of His is a tract of conducting fibres that carry impulses from atria to ventricles.
(iii) Impulses generated by SA node stimulates the atria and ventricles to contract simultaneously.
(iv) SA node has an inherent ability to generate nerve impulse at a higher rate compared to the rest of cardiac muscle fibres.