Mammal heart, chambers (Gross, Low)

Structure List Right ventricle Left ventricle Right auricle Left auricle Aorta Cranial vena cava Pulmonary trunk Left subclavian artery Brachiocephalic trunk Papillary muscle Chordae tendineae

The papillary muscles are attached to the AV valves by the chordae tendineae. They prevent the valves from involuting into the atria when the ventricles contract.