Formation of cardiac septa

• Septa are walls in the primitive atrium, ventricle and outflow tract
• Generation septa mechanisms:

  • differential growth and remodeling of the myocardium
  • generation of endocardial cushions
• Cardiac septa consist of two components: a muscular portion and a membranous (fibrous) portion.
• Differential growth and remodeling of the myocardium is responsible for the muscular portion
• Endocardial cushions are responsible for membranous portions
• endocardial cushions formation starts with the secretion of extracellular matrix by the myocardium during cardiac looping
• Endocardial cushions are mesenchymal-filled bulges and ridges
• cushions are crucial for septation and cardiac valve formation