Question

Following are the stages of pathway for conduction of an action potential through the heart
A. AV bundle 
B. Purkinje fibres 
C. AV node 
D. Bundle branches 
E. SA node
Choose the correct sequence of pathway from the options given below

• A. E-C-A-D-B
• B. A-E-C-B-D
• C. B-D-E-C-A
• D. E-A-D-B-C

Answer 1

The Correct Option is A

An action potential's conduction pathway through the heart follows specific stages that involve sequentially activating different regions of the heart's electrical system to coordinate a proper heartbeat. Here's the correct sequence:

1. SA node (Sinoatrial node): Initiates the electrical impulse as the natural pacemaker, which causes the atria to contract.
2. AV node (Atrioventricular node): Receives the impulse from the SA node and introduces a delay, allowing time for the ventricles to fill with blood before they contract.
3. AV bundle (Bundle of His): Transfers the impulse from the AV node to the ventricles, acting as a bridge.
4. Bundle branches: Conduct the impulse through the septum, dividing the signal towards the left and right ventricles.
5. Purkinje fibres: Spread the impulse throughout the ventricles, causing them to contract.

Thus, the correct sequence matching the provided options is E-C-A-D-B, which corresponds to SA node, AV node, AV bundle, Bundle branches, Purkinje fibres.