Review of Heart Development

The heart is one of the most important organs in the human body, and its development is complex and fascinating. This article will review the development of the heart from embryology through fetal life.

Early Embryonic Stage

During the early embryonic stage, the heart begins to form around day 22 of gestation. This process is known as cardiac morphogenesis and involves the formation of cardiac progenitor cells, which are then organized into a tube-like structure. This structure is known as the heart tube, and it begins to fold and twist into the recognizable four-chamber heart as the embryo grows. During this stage, the heart tube is divided into two chambers, the atrium and the ventricle, and is connected to the surrounding tissue by the bulbus cordis and sinus venosus. The heart tube also develops valves and septa that will divide the chambers and control the flow of blood through the heart.

Cardiac Looping

The next stage of heart development is known as cardiac looping. This occurs between days 24 and 26 of gestation, and involves the heart tube rotating around its own axis, forming the recognizable four-chamber heart. During this stage, the heart tube also begins to divide into the right and left ventricles, with the right ventricle forming first. The atria and ventricles are also divided into four chambers by the formation of the atrioventricular and interventricular septa.

Development of the Great Vessels

The next stage of heart development is the formation of the great vessels. These include the aorta, pulmonary artery, and the superior and inferior vena cava. The aorta is the main artery that carries blood away from the heart, while the pulmonary artery carries blood to the lungs. The superior and inferior vena cava are the veins that return blood to the heart from the body. During this stage, the aorticopulmonary septum begins to form, which divides the left and right sides of the heart.

Development of the Coronary Vessels

The last stage of heart development is the formation of the coronary vessels. These vessels are the arteries and veins that supply blood to the heart muscle. During this stage, the coronary arteries form from the aorta and the coronary veins form from the pulmonary artery. The coronary vessels then branch out to supply blood to the heart muscle, allowing it to function properly.

Conclusion

In conclusion, the development of the heart is a complex and fascinating process that starts in the early embryonic stage and continues through fetal life. During this process, the heart tube is formed and divided into two chambers, the atrium and ventricle. The heart then undergoes the stages of cardiac looping and the formation of the great vessels, before finally forming the coronary vessels that supply blood to the heart muscle. Through these stages, the heart is transformed from a simple tube into a four-chamber organ that is essential for life.