Which muscles pull the chordae tendineae?

• A. Papillary muscles
• B. Intercalated disks
• C. Diaphragm
• D. Skeletal muscles

Answer: (A)

Papillary muscles pull on the chordae tendineae to keep the atrioventricular valve leaflets from prolapsing during ventricular contraction. When the ventricles contract, these muscles tense the chordae, anchoring the valve cusps and preventing them from bulging into the atria, which maintains one-way blood flow. Intercalated disks are cell junctions between cardiac muscle cells, not muscles that move the chordae. The diaphragm and skeletal muscles don’t directly control the chordae tendineae or valve mechanics.