Question

Which of the following represents the correct sequence of the origin and conduction of action potential?

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

Answer 1

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

The correct sequence of the origin and conduction of action potential is
SA node $\to$ AV node $\to$ Bundle of His $\to$ Purkinje fibres.

The sinoatrial node is called a pacemaker as it generates the cardiac impulse. It is located in the right atrium. The atrioventricular node is in between the right atrium and the right ventricle. Bundle of His is situated in the interventricular septa. The bundle of His divides into two branches and gives rise to fine fibres called Purkinje fibres.

The electrochemical impulse generated by the sinoatrial node stimulates the atrioventricular node and carries the impulse to the two ventricles through the bundle of His and Purkinje fibres.