proepicardium

The proepicardium is a transient embryonic structure that plays a crucial role in the development of the heart. It is derived from the splanchnic mesoderm and is located between the epicardium and the myocardium. The proepicardium is a thin layer of mesothelial cells that covers the developing heart and contributes to the formation of the epicardium, which later becomes the visceral layer of the pericardium.

During the early stages of heart development, the proepicardium is a continuous layer that surrounds the entire heart. As the heart grows and differentiates, the proepicardium undergoes a process of delamination, where it separates into two layers: the epicardium and the subepicardium. The epicardium eventually forms the visceral pericardium, while the subepicardium contributes to the formation of the coronary arteries and the cardiac plexus.

The proepicardium also plays a role in the development of the coronary arteries. As the heart grows, the proepicardium invaginates to form the coronary arteries, which supply blood to the myocardium. The proepicardium also contributes to the formation of the cardiac plexus, a network of nerves that innervates the heart.

In summary, the proepicardium is a transient embryonic structure that is essential for the development of the heart. It contributes to the formation of the epicardium, coronary arteries, and cardiac plexus, and plays a crucial role in the growth and differentiation of the heart.