Question

The conduction mechanism consists of three stages. Which of the following is the correct order of events during this process?

• A. atrial depolarization → ventricular depolarization → atrial and ventricular repolarization
• B. ventricular repolarization → atrial depolarization → atrial and ventricular repolarization
• C. atrial and ventricular repolarization → ventricular depolarization → atrial depolarization
• D. ventricular repolarization→ atrial depolarization→ atrial and ventricular depolarization

Answer 1

The correct option is A

atrial depolarization → ventricular depolarization → atrial and ventricular repolarization

The conduction mechanism can be broken down into three major stages. The stages in order are atrial depolarization, ventricular depolarization which is followed by combined atrial and ventricular repolarization. Depolarization refers to the decrease in negative charge in the conduction cells of the heart and this drives contraction of the heart chambers.Repolarisation on the other hand increases negative charge in the conduction cells of the heart bringing about relaxation of heart chambers.