The cardiac chambers consist of two atria. two ventricles. and four valves The cardiac valves consist of thin flaps of tough, flexible, endothelium-covered fibrous art tissue firmly attached at the Pul base to the fibrous valve rings Movements of the valve leaflets are essentially passive, and the orientation of the cardiac valves is responsible for the unidirectional flow of blood through the heart.The cardiac chambers consist of two atria, two ventricles, and four valves The cardiac valves consist of thin flaps of tough, flexible, endothelium-covered fibrous tissue firmly attached at the base to the fibrous valve rings. Movements of the valve leaflets are essentially passive, and the orientation of the cardiac valves is responsible for the unidirectional flow of blood through the heart