Endokardkuddar

Endokardkuddar, a Swedish term, translates to "endocardial cushions" in English. These are localized thickenings of the endocardium, the inner lining of the heart chambers. They are transient structures that play a crucial role during embryonic heart development. Specifically, endocardial cushions form in the atrioventricular canal and the outflow tract of the developing heart.

During the fifth week of gestation, mesenchymal cells proliferate within the cardiac jelly and migrate to form these cushions. They are essential for the proper septation of the atrioventricular canal, which ultimately divides the common atrium and ventricle into their definitive left and right sides. Furthermore, endocardial cushions contribute to the formation of the atrioventricular valves, namely the mitral and tricuspid valves. They also influence the partitioning of the great arteries in the outflow tract.

The development and fusion of these cushions are critical for normal heart anatomy. Abnormalities in endocardial cushion formation or resorption can lead to congenital heart defects, such as atrioventricular septal defects, atrial septal defects, and ventricular septal defects. The process involves complex signaling pathways and cellular interactions, highlighting the intricate nature of cardiac embryogenesis. While present only during a specific developmental window, their significance in establishing a functional four-chambered heart is profound.