Fig 020 Purkinje System

Purkinje Fibers

The Purkinje system is a network of specialized muscle cells that carry cardiac impulses to the ventricles of the heart and cause them to contract.

Purkinje fibers extend from the atrioventricular (AV) node, divide into left and right branches, and travel beneath the endocardium of the ventricles.

Purkinje fibers are modified cardiac muscle cells and stain differently from surrounding muscle cells:

• Larger cells
• Large amounts of glycogen
• Fewer myofibrils

Purkinje fibers conduct cardiac impulses faster and more efficiently than normal cardiac muscle cells.

(Do not confuse cardiac Purkinje fibers with the neurons named Purkinje cells in the cerebellum.)