A cord, tendon, or nerve fiber. The chordae tendineae are string-like processes in the heart that attach the margins of the mitral and tricuspid valve leaflets to projections of the wall of the ventricle (papillary muscles). Rupture of the chordae, through injury, endocarditis, or degenerative changes, results in mitral incompetence.
The notochord is the embryonic structure around which the vertebral column develops.