Final answer:
The duration of atrial depolarization is approximately 100 ms.
Step-by-step explanation:
The duration of atrial depolarization can be calculated using the information provided. Atrial systole, which is the contraction of the atria, lasts approximately 100 ms. This is the time period during which the atria pump blood into the ventricles through the atrioventricular valves. It is important to note that atrial systole ends prior to ventricular systole, as the atrial muscle returns to diastole. Therefore, the duration of atrial depolarization is approximately 100 ms.