What do Purkinje fibers do?

What do Purkinje fibers do?

• A. They extend from the left and right bundles around the heart apex and invaginate into the ventricular myocardium.
• B. They generate impulses at the SA node.
• C. They supply blood to the myocardium.
• D. They modulate autonomic signals to the heart.

Answer: (A)

Purkinje fibers are the rapid-conduction pathway of the heart. They form a subendocardial network that extends from the left and right bundle branches, circling the heart apex and invaginating into the ventricular walls. This arrangement allows the electrical impulse to spread quickly and evenly through the ventricles, producing coordinated, synchronized contraction. They do not generate the heartbeat themselves (that’s the SA node’s job), they do not supply blood to the heart muscle (that’s the coronary circulation), and they do not modulate autonomic signals to the heart (that control comes from autonomic nerves).

Purkinje fibers are the rapid-conduction pathway of the heart. They form a subendocardial network that extends from the left and right bundle branches, circling the heart apex and invaginating into the ventricular walls. This arrangement allows the electrical impulse to spread quickly and evenly through the ventricles, producing coordinated, synchronized contraction.

They do not generate the heartbeat themselves (that’s the SA node’s job), they do not supply blood to the heart muscle (that’s the coronary circulation), and they do not modulate autonomic signals to the heart (that control comes from autonomic nerves).