part_of part of part of endocardium development extracellular matrix organization extracellular matrix organization involved in endocardium development GO:0061148 A process which results in the assembly, arrangement of constituent parts, or disassembly of an extracellular matrix of the endocardium. The endocardium is an anatomical structure comprised of an endothelium and an extracellular matrix that forms the innermost layer of tissue of the heart, and lines the heart chambers. 2010-06-03T09:18:02Z biological_process extracellular matrix organisation involved in endocardium development