What are trabeculae carneae?

What are trabeculae carneae?

• A. Small valves in the right atrium
• B. Large, irregular ridges inside the ventricular wall of the right ventricle
• C. Muscle bundles in the left atrium
• D. The lining of the SA node

Answer: (B)

Trabeculae carneae are large, irregular muscular ridges lining the inside of the ventricular walls. They are formed by bundles of cardiac muscle fibers and are not valves or structures of the atria. Some of these ridges extend as papillary muscles that anchor the chordae tendineae of the AV valves, helping prevent valve prolapse during contraction. The left atrium has its own muscular ridges (pectinate muscles), and the SA node is a specialized conduction tissue, not a trabeculated ventricular ridge.

Trabeculae carneae are large, irregular muscular ridges lining the inside of the ventricular walls. They are formed by bundles of cardiac muscle fibers and are not valves or structures of the atria. Some of these ridges extend as papillary muscles that anchor the chordae tendineae of the AV valves, helping prevent valve prolapse during contraction. The left atrium has its own muscular ridges (pectinate muscles), and the SA node is a specialized conduction tissue, not a trabeculated ventricular ridge.