When do the coronary arteries typically develop during gestation?

The coronary arteries typically develop during the third week of gestation. This period is significant because it marks the beginning of the embryonic development of the circulatory system. During this week, the heart's development accelerates, leading to the initial formation of major vascular structures, including the coronary arteries that supply blood to the myocardium. The development of the coronary arteries is crucial for the establishment of a functional circulatory system necessary for the growing embryo.

In contrast, the first week involves the early stages of conception and the formation of the blastocyst, while the fifth and tenth weeks are stages in which further differentiation and development occur but do not specifically pertain to the initial formation of coronary arteries. The fifth week involves more complex heart structure formation and septation, while by the tenth week, the heart is typically fully formed, but coronary artery development is considered to have established prior.