Definition

Noun: A Purkinje fiber is a specialized cardiac muscle fiber that is part of the Purkinje network. These fibers are located in the inner ventricular walls of the heart, beneath the endocardium. They are part of the heart's electrical conduction system, responsible for rapidly transmitting electrical impulses to ensure coordinated contraction of the heart ventricles.

Usage

Purkinje fibers are a specific anatomical and physiological term used in biology and medicine. * They are essential for the propagation of the cardiac action potential. * They are distinguished from ordinary cardiac muscle fibers by their ability to conduct electrical signals faster.

Examples

• The electrical impulse travels from the atrioventricular node through the bundle of His and into the Purkinje fibers.
• Damage to the Purkinje fibers can lead to conduction abnormalities and arrhythmias.
• Under the microscope, Purkinje fibers appear larger and contain more glycogen than typical myocardial cells.

Advanced Usage

• Purkinje network/system: The entire network of these specialized fibers within the ventricles.
  • The impulse spreads throughout the ventricle via the Purkinje network.
• Purkinje cell: A completely different type of neuron found in the cerebellum. It is critical to note this is a distinct term, though eponymously related.
  • Do not confuse cardiac Purkinje fibers with cerebellar Purkinje cells.

Variants and Related Words

• Purkinje network (n): The interconnected system of Purkinje fibers in the heart's ventricles.
• Purkinje cell (n): A large, GABAergic neuron in the cerebellar cortex with a distinct flask-shaped soma.
• Cardiac muscle fiber (n): The general type of muscle tissue found in the heart, of which Purkinje fibers are a specialized subset.
• Conduction system (n): The system of specialized cardiac cells that generates and conducts electrical impulses, including the SA node, AV node, bundle of His, and Purkinje fibers.

Synonyms

• Purkinje myocyte
• Subendocardial branch (refers to the terminal branches of the Purkinje network)

Related Phrases

• To conduct impulses: This is the primary function of Purkinje fibers.
  • Purkinje fibers are designed to conduct impulses rapidly.
• Ventricular contraction: The physiological outcome of the impulse propagation through the Purkinje fibers.
  • The activation of Purkinje fibers triggers synchronized ventricular contraction.

Noun

1. a specialized cardiac muscle fiber that is part of the Purkinje network