Question

Following are the stages of pathway for conduction of an action potential through the heart:

1. AV bundle
2. Purkinje fibres
3. AV node
4. Bundle branches
5. SA node

Choose the correct sequence of pathway from the options given below:

Options

• B - D - E - С - А

• E - A - D - В - C

• E - C - A - D - B

• A - E - C - B - D

Answer 1

E - C - A - D - B

Explanation:

The action potential produced by the SAN causes both atria to contract simultaneously, a process known as atrial systole. The bundle of His conveys the action potential to the entire ventricular musculature (Purkinje fibres) after the AVN and AV bundle carry it to the ventricular side.

Therefore, the proper action potential conduction pathway is SA → AV node → AV bundle → Bundle branches → Purkinje fibres.