Ventricular contraction is in command of :
1. S.A. Node
2. A.V. Node
3. Purkinje fibers
4. Papillary muscles
Bundle of His is a network of:
1. Muscle fibres distributed throughout the heart walls
2. Muscle fibres are found only in the ventricle wall
3. Nerve fibres distributed in ventricles
4. Nerve fibres found throughout the heart