This is a view of a ventricle opened to show one of the atrio-ventricular (AV) valves of the cow heart (the atrium has been mostly removed from the top in this view). The AV valves are found between the atria and the ventricles and ensure that blood flows in only one direction -- from the atrium to the ventricle.
The AV valves close when the right and left ventricles contract to expel blood into the pulmonary trunk (artery) and aorta, respectively.
The chordae tendinae are thin strands of connective tissue that anchor the leaflets of each AV valve so that they cannot open into the atrium (thus allowing backflow of blood into the atrium).
Back to: The circulatory system