Question

Rhythmic heart beat is maintained by a highly specialized excitatory and conductive system. The correct sequence of events will be

• A. Atrio-ventricular node$\to$ Bundle of His$\to$ Sino-atrio node$\to$ Network of Purkinje fibres
• B. Network of Purkinje fibres$\to$ Atrio-ventricular node$\to$ Sino-atrio node$\to$ Bundle of His
• C. Atrio-ventricular node$\to$ Sino-atrio-node$\to$ Bundle of His$\to$ Purkinje fibres
• D. Sino-atrial node$\to$ Atrio-ventricular node$\to$ Purkinje fibres$\to$ Bundle of His
• E. Sino-atrial node$\to$ Atrio-ventricular node$\to$ Bundle of His$\to$ Purkinje fibres

Answer 1

The correct option is E Sino-atrial node$\to$ Atrio-ventricular node$\to$ Bundle of His$\to$ Purkinje fibres

The sino-atrial node is the point where the impulse is generated and so it is known as the pacemaker of the heart. This is the regulatory point and then the impulse is conducted to the atrioventricular node. The contraction impulse then passes to the Bundle of His and then passed on to the wall of the ventricles through the Purkinje fibres. This impulse is responsible for the contraction and relaxation of the heart which allows the production of the heart beat.

This, the correct answer is option E.