Question

Choose the correct pathway of the transmission of impulses in the heart

• A. AV node $\to$ SA node $\to$ Bundle of His $\to$ Purkinje fibres
• B. SA node $\to$ AV node $\to$ Bundle of His $\to$ Purkinje fibres
• C. SA node $\to$ Bundle of His $\to$ AV node $\to$ purkinje fibres
• D. AV node $\to$ Bundle of His $\to$ SA node $\to$ Purkinje fibres

Answer 1

The correct option is B SA node $\to$ AV node $\to$ Bundle of His $\to$ Purkinje fibres

1. The sinoatrial node (SA node) generates the electric impulse that begins the heart beat.
2. The excitation wave travels throughout the muscle of each atrium, causing it to contract.
3. The atrioventricular node (AV node) is stimulated. The relatively slower conduction through this node allows time for the atria to contract and complete the filling of the ventricles.
4. The excitation wave travels rapidly through the bundle of His and then throughout the ventricular walls by means of the bundle branches and Purkinje fibers.