Purkinje fibers

Definition

Purkinje fibers are specialized conductive fibers located in the inner ventricular walls of the heart. They play a crucial role in transmitting electrical impulses to ensure coordinated contractions of the ventricles.

5 Must Know Facts For Your Next Test

1. Purkinje fibers rapidly conduct electrical impulses from the atrioventricular (AV) node to the ventricles.
2. They ensure that both ventricles contract simultaneously and efficiently.
3. These fibers are part of the heart's intrinsic conduction system and help maintain a regular heartbeat.
4. Purkinje fibers have fewer myofibrils and more mitochondria compared to typical cardiac muscle cells, which aids their conductivity.
5. Damage or dysfunction in Purkinje fibers can lead to arrhythmias or other conduction abnormalities.

Review Questions

• What is the primary function of Purkinje fibers in the heart?
• How do Purkinje fibers differ structurally from typical cardiac muscle cells?
• What could be a potential consequence of damaged Purkinje fibers?

Related terms

Atrioventricular (AV) Node: A key component in the heart's electrical conduction system that delays impulses before they pass to the ventricles.

Sinoatrial (SA) Node: The natural pacemaker of the heart responsible for initiating electrical impulses.

Bundle of His: A collection of heart muscle cells specialized for electrical conduction; it transmits impulses from the AV node to the Purkinje fibers.