Chordae tendineae is covered by what to prevent blood clotting?

The chordae tendineae are delicate, fibrous cords that attach the cusps of the heart valves to the papillary muscles. They are covered by a layer of endothelial cells, which helps to prevent blood clotting. Endothelial cells are specialized cells that line the inside of blood vessels and heart chambers. They produce a number of substances that help to keep blood flowing smoothly, including nitric oxide, prostacyclin, and thrombomodulin. Nitric oxide and prostacyclin inhibit platelet aggregation and vasoconstriction, while thrombomodulin activates the protein C anticoagulant pathway. These substances work together to create a slippery, non-thrombogenic surface that prevents blood from clotting on the chordae tendineae.