- The lining of the interior surface of the heart chambers. The endocardium consists of a layer of endothelial cells and an underlying layer of connective tissue.
* * *The innermost tunic of the heart, which includes endothelium and subendothelial connective tissue; in the atrial wall, smooth muscle and numerous elastic fibers also occur. [endo- + G. kardia, heart]
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* * *n.a delicate membrane, formed of flat endothelial cells, that lines the heart and is continuous with the lining of arteries and veins. At the openings of the heart cavities it is folded back on itself to form the cusps of the valves. It presents a smooth slippery surface, which does not impede blood flow.• endocardial adj.
* * *en·do·car·di·um (en″do-kahrґde-əm) [endo + Gr. kardia heart] [TA] the endothelial lining membrane of the cavities of the heart and the connective tissue bed on which it lies. This subendothelial connective tissue contains varying amounts of elastic and collagen fibers and smooth muscle cells. endocardial adj
Medical dictionary. 2011.