What fuses to create the right and left AV canal?

The development of the heart involves the formation of various structures that eventually lead to the separation of the atria and ventricles. The right and left atrioventricular (AV) canals are formed during the embryonic development of the heart, primarily through the fusion of the dorsal and ventral endocardial cushions. These cushions are specialized structures that arise from the lateral walls of the heart tube and play a critical role in the partitioning of the heart chambers.

As the heart develops, the dorsal and ventral endocardial cushions grow and eventually fuse in the midline, creating the AV septum. This process is essential for the proper separation of the left and right atrioventricular canals, allowing for normal flow from the atria to the ventricles.

Understanding this developmental process is crucial, as any disruption in the fusion of these structures can lead to congenital heart defects such as atrioventricular septal defects. Therefore, recognizing the role of the dorsal and ventral endocardial cushions in creating the AV canals helps clarify how the heart forms its complex structure.