One device measuring this structure's function uses twelve "leads" to output QRS complexes on 1-millimeter graph paper. This structure's tissue contains intercalated discs, and majority-collagen structures called chordae tendineae connect its tricuspid valve and papillary muscles. The Bundle of His and sinoatrial node send electrical signals to its Purkinje fibers. This organ has a mitral valve, and its dividers, or septa, separate the atria and 
One device measuring this structure's function uses twelve "leads" to output QRS complexes on 1-millimeter graph paper. This structure's tissue contains intercalated discs, and majority-collagen structures called chordae tendineae connect its tricuspid valve and papillary muscles. The Bundle of His and sinoatrial node send electrical signals to its Purkinje fibers. This organ has a mitral valve, and its dividers, or septa, separate the atria and ventricles, resulting in four chambers. For 10 points, name this organ below the aorta, which contracts in order to pump blood.
One device measuring this structure's function uses twelve "leads" to output QRS complexes on 1-millimeter graph paper.
heart