What is the role of papillary muscles?

What is the role of papillary muscles?

• A. Pump blood through semilunar valves
• B. Muscular projections that anchor chordae tendineae in the heart
• C. Generate the heartbeat
• D. Shield the AV valves from backflow

Answer: (B)

The key idea is how the valves between the atria and ventricles are held secure during contraction. Papillary muscles are muscular projections from the ventricular walls that anchor the chordae tendineae, the string-like cords attached to the leaflets of the mitral and tricuspid valves. When the ventricles contract, these muscles also pull on the chords, tenseing the valve leaflets so they don’t bulge back into the atria. This prevents prolapse and helps the valves stay closed during systole, ensuring blood is ejected into the aorta and pulmonary artery rather than regurgitating backward. They don’t generate the heartbeat or pump blood through the semilunar valves; their main role is to stabilize the AV valves by maintaining proper tension on the chordae tendineae.

The key idea is how the valves between the atria and ventricles are held secure during contraction. Papillary muscles are muscular projections from the ventricular walls that anchor the chordae tendineae, the string-like cords attached to the leaflets of the mitral and tricuspid valves. When the ventricles contract, these muscles also pull on the chords, tenseing the valve leaflets so they don’t bulge back into the atria. This prevents prolapse and helps the valves stay closed during systole, ensuring blood is ejected into the aorta and pulmonary artery rather than regurgitating backward. They don’t generate the heartbeat or pump blood through the semilunar valves; their main role is to stabilize the AV valves by maintaining proper tension on the chordae tendineae.