The _____ originate from small mounds of myocardium called papillary muscles and serve as anchors to prevent the cusps of the AV valves from inverting into the atria
a. Purkinje fibers
b. coronary sinuses
c. coronary arteries
d. chordae tendineae
D
Chordae tendineae are thin strands of connective tissue. On one end, they are attached to the underside of the AV valves. On the other end, they are attached to small mounds of myocardium called papillary muscles. Papillary muscles project inward from the lower portion of the ventricular walls. When the ventricles contract and relax, so do the papillary muscles. The papillary muscles adjust their tension on the chordae tendineae, preventing them from bulging too far into the atria.
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