When does septation of the heart begin?

Septation of the heart, the process by which the heart's chambers are divided, begins during embryonic development primarily between weeks 5 and 7. This critical period encompasses the formation of the interatrial septum, which separates the left and right atria, and the interventricular septum, which divides the left and right ventricles.

During this timeframe, the endocardial cushions also contribute to the development of the septa, influencing the separation of the four heart chambers. Proper timing in this process is essential for the correct development of the cardiovascular system, impacting overall cardiac function and structure.

Understanding the timeline of cardiac development helps practitioners recognize the critical phases during which congenital heart defects might arise if septation is improper. Therefore, the answer indicating weeks 5 to 7 is substantiated by our knowledge of embryonic cardiac development stages.