The origin of the coronary arteries is not entirely clear. In the literature, one finds two theories.
According to the first, endothelial tissue grows out of the aortic wall and connects with the subepicardial vessel plexus while the heart is developing.
Other researchers are of the opinion that the vessel plexus arises in situ and finds retrogradely a connection with the aorta. Cell markings in animal trials have substantiated that their coronary arteries develop from precursor cells in situ with the formation of the epicardial layer and attain a connection with the aorta secondarily. The muscle layer of the coronary arteries stems from the mesoderm and not, as in the aorta, partially from immigrated neural crest cells.