Organ
Purkinje fibers
Specialized muscle cells that distribute ventricular excitation
High-yield
Purkinje fibers are modified cardiac muscle cells, not nerve axons.
Overview
Purkinje cells form the terminal ventricular conducting network, mainly beneath the endocardium. Their large, glycogen-rich cell bodies contain fewer contractile myofibrils than working cardiomyocytes. Rapid spread through this network helps coordinate contraction across the ventricular walls.
Reference facts
- Location
- Predominantly beneath ventricular endocardium, continuing from bundle branches into the ventricular walls and papillary regions
- Parts
- Large conducting cardiomyocytes with abundant glycogen and relatively few myofibrils
- Blood supply
- Branches of the coronary circulation supplying the surrounding ventricular regions
- Innervation
- Cardiac autonomic activity modulates their electrical behavior
- Relations
- Connects the bundle-branch system with working ventricular muscle
- Function
- Spreads excitation rapidly; subsidiary automatic activity can emerge when normal pacing is lost
Clinical correlation
Premature activity from Purkinje tissue can trigger ventricular arrhythmias, including fibrillation in some patients. This is a potential arrhythmia mechanism, not a diagnosis made from anatomy alone.
Frequently asked questions
Where are the purkinje fibers located?
Predominantly beneath ventricular endocardium, continuing from bundle branches into the ventricular walls and papillary regions.
What do the purkinje fibers do?
Spreads excitation rapidly; subsidiary automatic activity can emerge when normal pacing is lost.
What are the parts of the purkinje fibers?
The parts of the purkinje fibers are the large conducting cardiomyocytes with abundant glycogen and relatively few myofibrils.
What is the blood supply of the purkinje fibers?
Branches of the coronary circulation supplying the surrounding ventricular regions.