The septum is formed during development as this muscular ridge of tissue grows upward from the apex, or the tip, and then fuses with a thinner membranous region coming down from the endocardial cushions.

室间隔在胚胎发育期间形成，这种组织肌肉嵴从心尖部往上长，并与从心内膜垫向下延伸的薄膜区域融合。